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• android database leak found IllegalStateException

  - by saravanan

  04-20 16:53:39.010: ERROR/Database(419): Leak found 04-20 16:53:39.010: ERROR/Database(419): java.lang.IllegalStateException: mPrograms size 1 04-20 16:53:39.010: ERROR/Database(419): at android.database.sqlite.SQLiteDatabase.finalize(SQLiteDatabase.java:1668) 04-20 16:53:39.010: ERROR/Database(419): at dalvik.system.NativeStart.run(Native Method) 04-20 16:53:39.010: ERROR/Database(419): Caused by: java.lang.IllegalStateException: /data/data/com.example.search/databases/rlite.db SQLiteDatabase created and never closed 04-20 16:53:39.010: ERROR/Database(419): at android.database.sqlite.SQLiteDatabase.(SQLiteDatabase.java:1694) 04-20 16:53:39.010: ERROR/Database(419): at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:738) 04-20 16:53:39.010: ERROR/Database(419): at android.database.sqlite.SQLiteDatabase.openOrCreateDatabase(SQLiteDatabase.java:760) 04-20 16:53:39.010: ERROR/Database(419): at android.database.sqlite.SQLiteDatabase.openOrCreateDatabase(SQLiteDatabase.java:753) 04-20 16:53:39.010: ERROR/Database(419): at android.app.ApplicationContext.openOrCreateDatabase(ApplicationContext.java:473) 04-20 16:53:39.010: ERROR/Database(419): at android.content.ContextWrapper.openOrCreateDatabase(ContextWrapper.java:193) 04-20 16:53:39.010: ERROR/Database(419): at android.database.sqlite.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java:98) 04-20 16:53:39.010: ERROR/Database(419): at com.example.search.Database.(Database.java:33) 04-20 16:53:39.010: ERROR/Database(419): at com.example.search.JobDetails.applyJob(JobDetails.java:120) 04-20 16:53:39.010: ERROR/Database(419): at com.example.search.JobDetails.jobdetailsAction(JobDetails.java:98) 04-20 16:53:39.010: ERROR/Database(419): at java.lang.reflect.Method.invokeNative(Native Method) 04-20 16:53:39.010: ERROR/Database(419): at java.lang.reflect.Method.invoke(Method.java:521) 04-20 16:53:39.010: ERROR/Database(419): at android.view.View$1.onClick(View.java:2026) 04-20 16:53:39.010: ERROR/Database(419): at android.view.View.performClick(View.java:2364) 04-20 16:53:39.010: ERROR/Database(419): at android.view.View.onTouchEvent(View.java:4179) 04-20 16:53:39.010: ERROR/Database(419): at android.widget.TextView.onTouchEvent(TextView.java:6540) 04-20 16:53:39.010: ERROR/Database(419): at android.view.View.dispatchTouchEvent(View.java:3709) 04-20 16:53:39.010: ERROR/Database(419): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884) 04-20 16:53:39.010: ERROR/Database(419): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884) 04-20 16:53:39.010: ERROR/Database(419): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884) 04-20 16:53:39.010: ERROR/Database(419): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884) 04-20 16:53:39.010: ERROR/Database(419): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884) 04-20 16:53:39.010: ERROR/Database(419): at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:1659) 04-20 16:53:39.010: ERROR/Database(419): at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1107) 04-20 16:53:39.010: ERROR/Database(419): at android.app.Activity.dispatchTouchEvent(Activity.java:2061) 04-20 16:53:39.010: ERROR/Database(419): at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1643) 04-20 16:53:39.010: ERROR/Database(419): at android.view.ViewRoot.handleMessage(ViewRoot.java:1691) 04-20 16:53:39.010: ERROR/Database(419): at android.os.Handler.dispatchMessage(Handler.java:99) 04-20 16:53:39.010: ERROR/Database(419): at android.os.Looper.loop(Looper.java:123) 04-20 16:53:39.010: ERROR/Database(419): at android.app.ActivityThread.main(ActivityThread.java:4363) 04-20 16:53:39.010: ERROR/Database(419): at java.lang.reflect.Method.invokeNative(Native Method) 04-20 16:53:39.010: ERROR/Database(419): at java.lang.reflect.Method.invoke(Method.java:521) 04-20 16:53:39.010: ERROR/Database(419): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860) 04-20 16:53:39.010: ERROR/Database(419): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618) 04-20 16:53:39.010: ERROR/Database(419): at dalvik.system.NativeStart.main(Native Method) when i read the database show error like this. please do reply me

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• Scaling MKMapView Annotations relative to the zoom level

  - by Jonathan

  The Problem I'm trying to create a visual radius circle around a annonation, that remains at a fixed size in real terms. Eg. So If i set the radius to 100m, as you zoom out of the Map view the radius circle gets progressively smaller. I've been able to achieve the scaling, however the radius rect/circle seems to "Jitter" away from the Pin Placemark as the user manipulates the view. The Manifestation Here is a video of the behaviour. The Implementation The annotations are added to the Mapview in the usual fashion, and i've used the delegate method on my UIViewController Subclass (MapViewController) to see when the region changes. -(void)mapView:(MKMapView *)pMapView regionDidChangeAnimated:(BOOL)animated{ //Get the map view MKCoordinateRegion region; CGRect rect; //Scale the annotations for( id<MKAnnotation> annotation in [[self mapView] annotations] ){ if( [annotation isKindOfClass: [Location class]] && [annotation conformsToProtocol:@protocol(MKAnnotation)] ){ //Approximately 200 m radius region.span.latitudeDelta = 0.002f; region.span.longitudeDelta = 0.002f; region.center = [annotation coordinate]; rect = [[self mapView] convertRegion:foo toRectToView: self.mapView]; if( [[[self mapView] viewForAnnotation: annotation] respondsToSelector:@selector(setRadiusFrame:)] ){ [[[self mapView] viewForAnnotation: annotation] setRadiusFrame:rect]; } } } The Annotation object (LocationAnnotationView)is a subclass of the MKAnnotationView and it's setRadiusFrame looks like this -(void) setRadiusFrame:(CGRect) rect{ CGPoint centerPoint; //Invert centerPoint.x = (rect.size.width/2) * -1; centerPoint.y = 0 + 55 + ((rect.size.height/2) * -1); rect.origin = centerPoint; [self.radiusView setFrame:rect]; } And finally the radiusView object is a subclass of a UIView, that overrides the drawRect method to draw the translucent circles. setFrame is also over ridden in this UIView subclass, but it only serves to call [UIView setNeedsDisplay] in addition to [UIView setFrame:] to ensure that the view is redrawn after the frame has been updated. The radiusView object's (CircleView) drawRect method looks like this -(void) drawRect:(CGRect)rect{ //NSLog(@"[CircleView drawRect]"); [self setBackgroundColor:[UIColor clearColor]]; //Declarations CGContextRef context; CGMutablePathRef path; //Assignments context = UIGraphicsGetCurrentContext(); path = CGPathCreateMutable(); //Alter the rect so the circle isn't cliped //Calculate the biggest size circle if( rect.size.height > rect.size.width ){ rect.size.height = rect.size.width; } else if( rect.size.height < rect.size.width ){ rect.size.width = rect.size.height; } rect.size.height -= 4; rect.size.width -= 4; rect.origin.x += 2; rect.origin.y += 2; //Create paths CGPathAddEllipseInRect(path, NULL, rect ); //Create colors [[self areaColor] setFill]; CGContextAddPath( context, path); CGContextFillPath( context ); [[self borderColor] setStroke]; CGContextSetLineWidth( context, 2.0f ); CGContextSetLineCap(context, kCGLineCapSquare); CGContextAddPath(context, path ); CGContextStrokePath( context ); CGPathRelease( path ); //CGContextRestoreGState( context ); } Thanks for bearing with me, any help is appreciated. Jonathan

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• Android: Custom ListAdapter extending BaseAdapter crashes on application launch.

  - by Danny

  Data being pulled from a local DB, then mapped using a cursor. Custom Adapter displays data similar to a ListView. As items are added/deleted from the DB, the adapter is supposed to refresh. The solution attempted below crashes the application at launch. Any suggestions? Thanks in advance, -D @Override public View getView(int position, View convertView, ViewGroup parent) { View v = convertView; ViewGroup p = parent; if (v == null) { LayoutInflater vi = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); v = vi.inflate(R.layout.items_row, p); } int size = mAdapter.getCount(); Log.d(TAG, "position " + position + " Size " + size); if(size != 0){ if(position < size) return mAdapter.getView(position, v, p); Log.d(TAG, "-position " + position + " Size " + size); } return null; } Errors: 03-23 00:14:10.392: ERROR/AndroidRuntime(718): java.lang.UnsupportedOperationException: addView(View, LayoutParams) is not supported in AdapterView 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at android.widget.AdapterView.addView(AdapterView.java:461) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at android.view.LayoutInflater.inflate(LayoutInflater.java:415) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at android.view.LayoutInflater.inflate(LayoutInflater.java:320) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at android.view.LayoutInflater.inflate(LayoutInflater.java:276) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at com.xyz.abc.CustomSeparatedListAdapter.getView(CustomSeparatedListAdapter.java:90) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at android.widget.AbsListView.obtainView(AbsListView.java:1273) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at android.widget.ListView.makeAndAddView(ListView.java:1658) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at android.widget.ListView.fillDown(ListView.java:637) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at android.widget.ListView.fillFromTop(ListView.java:694) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at android.widget.ListView.layoutChildren(ListView.java:1516) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at android.widget.AbsListView.onLayout(AbsListView.java:1112) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at android.view.View.layout(View.java:6569) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at android.widget.FrameLayout.onLayout(FrameLayout.java:333) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at android.view.View.layout(View.java:6569) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at android.widget.FrameLayout.onLayout(FrameLayout.java:333) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at android.view.View.layout(View.java:6569) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at android.widget.FrameLayout.onLayout(FrameLayout.java:333) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at android.view.View.layout(View.java:6569) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1119) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at android.widget.LinearLayout.layoutVertical(LinearLayout.java:998) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at android.widget.LinearLayout.onLayout(LinearLayout.java:918) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at android.view.View.layout(View.java:6569) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at android.widget.FrameLayout.onLayout(FrameLayout.java:333) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at android.view.View.layout(View.java:6569) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at android.widget.FrameLayout.onLayout(FrameLayout.java:333) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at android.view.View.layout(View.java:6569) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at android.widget.FrameLayout.onLayout(FrameLayout.java:333) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at android.view.View.layout(View.java:6569) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at android.view.ViewRoot.performTraversals(ViewRoot.java:979) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at android.view.ViewRoot.handleMessage(ViewRoot.java:1613) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at android.os.Handler.dispatchMessage(Handler.java:99) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at android.os.Looper.loop(Looper.java:123) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at android.app.ActivityThread.main(ActivityThread.java:4203) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at java.lang.reflect.Method.invokeNative(Native Method) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at java.lang.reflect.Method.invoke(Method.java:521) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:791) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:549) 03-23 00:14:10.392: ERROR/AndroidRuntime(718): at dalvik.system.NativeStart.main(Native Method)

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• Critical tools that every Java Developer should have in his toolbelt?

  - by Timur Fanshteyn

  I was trying to compile a list of tools that a good Java Developer should be know of, and keep in his Developer Tool Belt I can think of a few Eclipse Development Environment - There are other IDEs, but you should know how Eclipse of eclipse. JUnit - Java Unit Testing Framework. Of course there are others, but... ANT Maven Soap UI - for testing SOAP endpoints jrat - Java Profiler. I don't know of other good Java profilers Java Decompiler - For when you just have to know what's in the jar file

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• Java: what is the class for the isBinary-method?

  - by HH

  I am accustomed to java.io.* and java.util.* but not to the tree: com.starbase.util Class FileUtils java.lang.Object | +--com.starbase.util.FileUtils Source. So which class should I import to use the isBinary-method? Do I do "import java.lang.Object;" or "import java.lang.Object.com.starbase.util.FileUtils;"?

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• Object as itemValue in <f:selectItems>

  - by Ehsun

  Is it possible to have objects as itemValue in tag? for example I have a class Foo: public class Foo { private int id; private String name; private Date date; } And another class Bar public class Bar { private Foo foos; } public class BarBean { private Set<Foo> foos; } Now in a Bean called BarBean I need to have a to get the Foo of the current Bar from User like this: <h:selectOneMenu value="#{barBean.bar.foo}" required="true"> <f:selectItems value="#{barBean.foos}" var="foo" itemLabel="#{foo.name}" itemValue="#{foo}" /> </h:selectOneMenu> ---------------edited: my converter: package ir.khorasancustoms.g2g.converters; import ir.khorasancustoms.g2g.persistance.CatalogValue; import java.util.ResourceBundle; import javax.faces.application.FacesMessage; import javax.faces.component.UIComponent; import javax.faces.context.FacesContext; import javax.faces.convert.Converter; import javax.faces.convert.FacesConverter; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.Transaction; import org.hibernate.cfg.Configuration; @FacesConverter("ir.khorasancustoms.CatalogValueConverter") public class CatalogValueConverter implements Converter { @Override public Object getAsObject(FacesContext context, UIComponent component, String value) { SessionFactory factory = new Configuration().configure().buildSessionFactory(); Session session = factory.openSession(); try { int id = Integer.parseInt(value); CatalogValue catalogValue = (CatalogValue) session.load(CatalogValue .class, id); return catalogValue; } catch (Exception ex) { Transaction tx = session.getTransaction(); if (tx.isActive()) { tx.rollback(); } ResourceBundle rb = ResourceBundle.getBundle("application"); String message = rb.getString("databaseConnectionFailed"); FacesContext.getCurrentInstance().addMessage(null, new FacesMessage(FacesMessage.SEVERITY_FATAL, message, message)); } finally { session.close(); } return null; } @Override public String getAsString(FacesContext context, UIComponent component, Object value) { return ((CatalogValue) value).getId() + ""; } } and my facelet: <h:outputText value="#{lbls.paymentUnit}:"/> <h:selectOneMenu id="paymentUnit" label="#{lbls.paymentUnit}" value="#{price.price.ctvUnit}" required="true"> <f:selectItems value="#{price.paymentUnits}"/> <f:converter converterId="ir.khorasancustoms.CatalogValueConverter"/> </h:selectOneMenu> <h:message for="paymentUnit" infoClass="info" errorClass="error" warnClass="warning" fatalClass="fatal"/>

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• Why does limiting my virtual memory to 512MB with ulimit -v crash the JVM?

  - by Narinder Kumar

  I am trying to enforce maximum memory a program can consume on a Unix system. I thought ulimit -v should do the trick. Here is a sample Java program I have written for testing : import java.util.*; import java.io.*; public class EatMem { public static void main(String[] args) throws IOException, InterruptedException { System.out.println("Starting up..."); System.out.println("Allocating 128 MB of Memory"); List<byte[]> list = new LinkedList<byte[]>(); list.add(new byte[134217728]); //128 MB System.out.println("Done...."); } } By default, my ulimit settings are (output of ulimit -a) : core file size (blocks, -c) 0 data seg size (kbytes, -d) unlimited scheduling priority (-e) 0 file size (blocks, -f) unlimited pending signals (-i) 31398 max locked memory (kbytes, -l) 64 max memory size (kbytes, -m) unlimited open files (-n) 1024 pipe size (512 bytes, -p) 8 POSIX message queues (bytes, -q) 819200 real-time priority (-r) 0 stack size (kbytes, -s) 8192 cpu time (seconds, -t) unlimited max user processes (-u) 31398 virtual memory (kbytes, -v) unlimited file locks (-x) unlimited When I execute my java program (java EatMem), it executes without any problems. Now I try to limit max memory available to any program launched in the current shell to 512MB by launching the following command : ulimit -v 524288 ulimit -a output shows the limit to be set correctly (I suppose): core file size (blocks, -c) 0 data seg size (kbytes, -d) unlimited scheduling priority (-e) 0 file size (blocks, -f) unlimited pending signals (-i) 31398 max locked memory (kbytes, -l) 64 max memory size (kbytes, -m) unlimited open files (-n) 1024 pipe size (512 bytes, -p) 8 POSIX message queues (bytes, -q) 819200 real-time priority (-r) 0 stack size (kbytes, -s) 8192 cpu time (seconds, -t) unlimited max user processes (-u) 31398 virtual memory (kbytes, -v) 524288 file locks (-x) unlimited If I now try to execute my java program, it gives me the following error: Error occurred during initialization of VM Could not reserve enough space for object heap Could not create the Java virtual machine. Ideally it should not happen as my Java program is only taking around 128MB of memory which is well within my specified ulimit parameters. If I change the arguments to my Java program as below: java -Xmx256m EatMem The program again works fine. While trying to give more memory than limited by ulimit like : java -Xmx800m EatMem results in expected error. Why the program fails to execute in the first case after setting ulimit ? I have tried the above test on Ubuntu 11.10 and 12.0.4 with Java 1.6 and Java 7

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• Java 1.4 to Java 6 migration

  - by joesatch

  Hi, I have some enterprise apps running on Java 1.4. They mostly invoke Stored Proces on DB, Parse XML files (Not too large files, at the most few megs), read/write from/to disk. We have a requirement where now we have to migrate these apps to Java 6(No code changes to be done at all). My questions: If I dont recompile my apps under Java 6 and just run them with it, will it work fine (I know they 'should'). But if somebody thinks other way round, could you kindly share your thoughts please? More important question is - Will it have any perfomance impact?. As in, App compiled on 1.4 and running on 1.6 vs App compiled and running on 1.6. Is 1.6 gonna do any bytecode optimization for the same old peace of code compared to 1.4? Many Thanks js

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• How to serialize Java primitives using Jersey REST

  - by Olvagor

  In my application I use Jersey REST to serialize complex objects. This works quite fine. But there are a few method which simply return an int or boolean. Jersey can't handle primitive types (to my knowledge), probably because they're no annotated and Jersey has no default annotation for them. I worked around that by creating complex types like a RestBoolean or RestInteger, which simply hold an int or boolean value and have the appropriate annotations. Isn't there an easier way than writing these container objects?

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• Java Spring 3.0 MVC Annotation vs COC. Whats the preferred method in the Java community?

  - by Athens

  I am using Spring's MVC framework for an application I'm hosting on Google's App Engine. So far, my controllers are registered via the @Controller annotation; however, prior to getting into Spring, I evaluated ASP.net MVC 2 which requires no configuration and is based on convention. Is convention over configuration (COC) the current and preferred method in the Java community to implement MVC with Spring. Also, this may be a result of my limited knowledge so far but i noticed that i could only instantiate my Controllers the required constuctor injection if i use the COC method via the ControllerClassNameHandlerMapping. For instance the following controller bean config will fail if i use the defaultannotationhandlermapping. <bean id="c" class="com.domain.TestController"> <constructor-arg ref="service" /> </bean> <bean id="service" class="com.domain.Service" /> My com.domain.TestController controller works fine if i use ControllerClassNameHandlerMapping/COC but it results in an error when i use defaultannotationhandlermapping/Annotations.

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• Android passing an arraylist back to parent activity

  - by Nicklas O

  Hi there. I've been searching for a simple example of this with no luck. In my android application I have two activities: 1. The main activity which is launched at startup 2. A second activity which is launched by pressing a button on the main activty. When the second activity is finished (by pressing a button) I want it to send back an ArrayList of type MyObject to the main activity and close itself, which the main activity can then do whatever with it. How would I go about achieving this? I have been trying a few things but it is crashing my application when I start the second activity. When the user presses button to launch second activity: Intent i = new Intent(MainActivity.this, secondactivity.class); startActivityForResult(i, 1); The array which is bundled back after pressing a button on the second activity: Intent intent= getIntent(); Bundle b = new Bundle(); b.putParcelableArrayList("myarraylist", mylist); intent.putExtras(b); setResult(RESULT_OK, intent); finish(); And finally a listener on the main activity (although I'm not sure of 100% when this code launches...) protected void onActivityResult(int requestCode, int resultCode, Intent data) { super.onActivityResult(requestCode, resultCode, data); if(resultCode==RESULT_OK && requestCode==1){ Bundle extras = data.getExtras(); final ArrayList<MyObject> mylist = extras.getParcelableArrayList("myarraylist"); Toast.makeText(MainActivity.this, mylist.get(0).getName(), Toast.LENGTH_SHORT).show(); } } Any ideas where I am going wrong? The onActivityResult() seems to be crashing my application. EDIT: This is my class MyObject, its called plan and has a name and an id import android.os.Parcel; import android.os.Parcelable; public class Plan implements Parcelable{ private String name; private String id; public Plan(){ } public Plan(String name, String id){ this.name = name; this.id = id; } public String getName(){ return name; } public void setName(String name){ this.name = name; } public String getId(){ return id; } public void setId(String id){ this.id = id; } public String toString(){ return "Plan ID: " + id + " Plan Name: " + name; } @Override public int describeContents() { // TODO Auto-generated method stub return 0; } @Override public void writeToParcel(Parcel dest, int flags) { dest.writeString(id); dest.writeString(name); } public static final Parcelable.Creator<Plan> CREATOR = new Parcelable.Creator<Plan>() { public Plan createFromParcel(Parcel in) { return new Plan(); } @Override public Plan[] newArray(int size) { // TODO Auto-generated method stub return new Plan[size]; } }; } This is my logcat E/AndroidRuntime( 293): java.lang.RuntimeException: Unable to instantiate activ ity ComponentInfo{com.daniel.android.groupproject/com.me.android.projec t.secondactivity}: java.lang.NullPointerException E/AndroidRuntime( 293): at android.app.ActivityThread.performLaunchActiv ity(ActivityThread.java:2417) E/AndroidRuntime( 293): at android.app.ActivityThread.handleLaunchActivi ty(ActivityThread.java:2512) E/AndroidRuntime( 293): at android.app.ActivityThread.access$2200(Activi tyThread.java:119) E/AndroidRuntime( 293): at android.app.ActivityThread$H.handleMessage(Ac tivityThread.java:1863) E/AndroidRuntime( 293): at android.os.Handler.dispatchMessage(Handler.ja va:99) E/AndroidRuntime( 293): at android.os.Looper.loop(Looper.java:123) E/AndroidRuntime( 293): at android.app.ActivityThread.main(ActivityThrea d.java:4363) E/AndroidRuntime( 293): at java.lang.reflect.Method.invokeNative(Native Method) E/AndroidRuntime( 293): at java.lang.reflect.Method.invoke(Method.java:5 21) E/AndroidRuntime( 293): at com.android.internal.os.ZygoteInit$MethodAndA rgsCaller.run(ZygoteInit.java:860) E/AndroidRuntime( 293): at com.android.internal.os.ZygoteInit.main(Zygot eInit.java:618) E/AndroidRuntime( 293): at dalvik.system.NativeStart.main(Native Method) E/AndroidRuntime( 293): Caused by: java.lang.NullPointerException E/AndroidRuntime( 293): at com.daniel.android.groupproject.login.<init>( login.java:51) E/AndroidRuntime( 293): at java.lang.Class.newInstanceImpl(Native Method ) E/AndroidRuntime( 293): at java.lang.Class.newInstance(Class.java:1479) E/AndroidRuntime( 293): at android.app.Instrumentation.newActivity(Instr umentation.java:1021) E/AndroidRuntime( 293): at android.app.ActivityThread.performLaunchActiv ity(ActivityThread.java:2409) E/AndroidRuntime( 293): ... 11 more

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• What is an Enterprise Java Bean really?

  - by HDave

  On the Tomcat FAQ it says: "Tomcat is not an EJB server. Tomcat is not a full J2EE server." But if I: use Spring to supply an application context annotate my entities with JPA annotations (and use Hibernate as a JPA provider) configure C3P0 as a connection pooling data source annotate my service methods with @Transactional (and use Atomikos as JTA provider) Use JAXB for marshalling and unmarshalling and possibly add my own JNDI capability then don't I effectively have a JEE application server? And then aren't my beans EJBs? Or is there some other defining characteristic? What is it that a JEE compliant app server gives you that you can't easily/readily get from Tomcat with some 3rd party subsystems?

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• What are the alternatives for Java authentication?

  - by Crusader

  Preferably something that integrates well with a Flex front end. Yes the Spring Security guys say this is possible, but all examples seem to use legacy jsp tag libraries making them half useless as examples. I don't want to spend a month setting up and learning how to use a security tool. I would like a tool which supports using annotations (@RolesAllowed etc), MINIMAL XML, and 'remember-me' features (not cookie based). Apache Shiro seems to support Flex/Silverlight/Swing as well but I'd like to know if there are any other alternatives that are NOT container specific.

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• Beginning Java (Working with Arrays; Class Assignment)

  - by Jason

  I am to the point where I feel as if I correctly wrote the code for this homework assignment. We were given a skeleton and 2 classes that we had to import (FileIOHelper and Student). /* * Created: *** put the date here *** * * Author: *** put your name here *** * * The program will read information about students and their * scores from a file, and output the name of each student with * all his/her scores and the total score, plus the average score * of the class, and the name and total score of the students with * the highest and lowest total score. */ // import java.util.Scanner; import java.io.*; // C:\Users\Adam\info.txt public class Lab6 { public static void main(String[] args) throws IOException { // Fill in the body according to the following comments Scanner key boardFile = new Scanner(System.in); // Input file name String filename = getFileName(keyboardFile); //Open the file // Input number of students int numStudents = FileIOHelper.getNumberOfStudents(filename); Student students[] = new Student[numStudents]; // Input all student records and create Student array and // integer array for total scores int totalScore[] = new int[students.length]; for (int i = 0; i < students.length; i++){ for(int j = 1; j < 4; j++){ totalScore[i] = totalScore[i] + students[i].getScore(j); } } // Compute total scores and find students with lowest and // highest total score int maxScore = 0; int minScore = 0; for(int i = 0; i < students.length; i++){ if(totalScore[i] >= totalScore[maxScore]){ maxScore = i; } else if(totalScore[i] <= totalScore[minScore]){ minScore = i; } } // Compute average total score int allScores = 0; int average = 0; for (int i = 0; i < totalScore.length; i++){ allScores = allScores + totalScore[i]; } average = allScores / totalScore.length; // Output results outputResults(students, totalScore, maxScore, minScore, average); } // Given a Scanner in, this method prompts the user to enter // a file name, inputs it, and returns it. private static String getFileName(Scanner in) { // Fill in the body System.out.print("Enter the name of a file: "); String filename = in.next(); return filename; // Do not declare the Scanner variable in this method. // You must use the value this method receives in the // argument (in). } // Given the number of students records n to input, this // method creates an array of Student of the appropriate size, // reads n student records using the FileIOHelper, and stores // them in the array, and finally returns the Student array. private static Student[] getStudents(int n) { Student[] myStudents = new Student[n]; for(int i = 0; i <= n; i++){ myStudents[i] = FileIOHelper.getNextStudent(); } return myStudents; } // Given an array of Student records, an array with the total scores, // the indices in the arrays of the students with the highest and // lowest total scores, and the average total score for the class, // this method outputs a table of all the students appropriately // formatted, plus the total number of students, the average score // of the class, and the name and total score of the students with // the highest and lowest total score. private static void outputResults( Student[] students, int[] totalScores, int maxIndex, int minIndex, int average ) { // Fill in the body System.out.println("\nName \t\tScore1 \tScore2 \tScore3 \tTotal"); System.out.println("--------------------------------------------------------"); for(int i = 0; i < students.length; i++){ outputStudent(students[i], totalScores[i], average); System.out.println(); } System.out.println("--------------------------------------------------------"); outputNumberOfStudents(students.length); outputAverage(average); outputMaxStudent(students[maxIndex], totalScores[maxIndex]); outputMinStudent(students[minIndex], totalScores[minIndex]); System.out.println("--------------------------------------------------------"); } // Given a Student record, the total score for the student, // and the average total score for all the students, this method // outputs one line in the result table appropriately formatted. private static void outputStudent(Student s, int total, int avg) { System.out.print(s.getName() + "\t"); for(int i = 1; i < 4; i++){ System.out.print(s.getScore(i) + "\t"); } System.out.print(total + "\t"); if(total < avg){ System.out.print("-"); }else if(total > avg){ System.out.print("+"); }else{ System.out.print("="); } } // Given the number of students, this method outputs a message // stating what the total number of students in the class is. private static void outputNumberOfStudents(int n) { System.out.println("The total number of students in this class is: \t" + n); } // Given the average total score of all students, this method // outputs a message stating what the average total score of // the class is. private static void outputAverage(int average) { System.out.println("The average total score of the class is: \t" + average); } // Given the Student with highest total score and the student's // total score, this method outputs a message stating the name // of the student and the highest score. private static void outputMaxStudent( Student student, int score ) { System.out.println(student.getName() + " got the maximum total score of: \t" + score); } // Given the Student with lowest total score and the student's // total score, this method outputs a message stating the name // of the student and the lowest score. private static void outputMinStudent( Student student, int score ) { System.out.println(student.getName() + " got the minimum total score of: \t" + score); } } But now I get an error at the line totalScore[i] = totalScore[i] + students[i].getScore(j); Exception in thread "main" java.lang.NullPointerException at Lab6.main(Lab6.java:42)

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• MYSQL LIMIT not working as expected - Java

  - by Sirish

  I have this weird problem in java when trying to fetch records from MYSql database by using the limit function in the query. Not sure what went wrong or did wrong, this query is giving me a hard time. Issue - When I run this query through my java program it returns all the records and not limiting the records to 10 as given in the limit. The same query when ran in MYSql command line, it execute very well and fetches me only 10 recrods. Below is the java code and query. Any help or support is appreciated.! Java code - public UserVO getApplUserDetailsList(UserVO userVO) throws CAPDAOException { List<UserVO> returnList = null; String methodName = "getApplUserDetails()"; Session session = null; String queryString = null; Transaction transaction = null; PreparedStatement ps = null; ResultSet rs = null; if(userVO == null) { logger.writeToTivoliAlertLog(className, CAPConstants.ERROR, methodName, null, "userVO returned null. Busines validation error.!", null); throw new CAPDAOException("userVO returned null. Busines validation error.!",CAPException.BUSINESS_VALIDATION_ERROR_SECURITY); } try { returnList = new ArrayList<UserVO>(); System.out.println(""); String appusr = userVO.getAppUsrNm(); session = getSession(); transaction = session.beginTransaction(); if(userVO.getAppUsrRoleCd()!=null && !userVO.getAppUsrRoleCd().trim().equalsIgnoreCase(CAPConstants.DEFAULT_DROPDOWN_VALUE)){ queryString = "SELECT " + "APPL_USR_ID,APPL_USR_NM,APPL_USR_FRST_NM, " + "APPL_USR_LST_NM,ACCESS_ROLE_CD " + "FROM APPL_USR " + "WHERE " + "APPL_USR_NM LIKE ?"+ " AND APPL_USR_FRST_NM LIKE ?"+ " AND APPL_USR_LST_NM LIKE ?"+ " AND ACCESS_ROLE_CD = ?"+ " AND APPL_USR_ID != ?"; ps = session.connection().prepareStatement(queryString); ps.setString(1,userVO.getAppUsrNm()+CAPConstants.PERCENTILE_SYMBOL); ps.setString(2,userVO.getAppUsrFirstNm()+CAPConstants.PERCENTILE_SYMBOL); ps.setString(3,userVO.getAppUsrLastNm()+CAPConstants.PERCENTILE_SYMBOL); ps.setString(4,userVO.getAppUsrRoleCd()); ps.setInt(5, 1); } else { queryString = "SELECT " + "APPL_USR_ID,APPL_USR_NM,APPL_USR_FRST_NM, " + "APPL_USR_LST_NM,ACCESS_ROLE_CD " + "FROM APPL_USR " + "WHERE " + "APPL_USR_NM LIKE ?"+ " AND APPL_USR_FRST_NM LIKE ?"+ " AND APPL_USR_LST_NM LIKE ?"+ " AND APPL_USR_ID != ?"; ps = session.connection().prepareStatement(queryString); ps.setString(1,userVO.getAppUsrNm()+CAPConstants.PERCENTILE_SYMBOL); ps.setString(2,userVO.getAppUsrFirstNm()+CAPConstants.PERCENTILE_SYMBOL); ps.setString(3,userVO.getAppUsrLastNm()+CAPConstants.PERCENTILE_SYMBOL); ps.setInt(4, 1); } if(userVO.getQueryAction()!=null && userVO.getQueryAction().equals(CAPConstants.GET_DATA)) queryString += " ORDER BY APPL_USR_ID LIMIT " + userVO.getPAGE_MIN_LIMIT() + ", " + userVO.getPAGE_MAX_LIMIT(); else queryString += " ORDER BY APPL_USR_ID"; rs = ps.executeQuery(); if(userVO.getQueryAction()!=null && userVO.getQueryAction().equals(CAPConstants.GET_DATA)) { int tempCOunt = 0; while(rs!=null && rs.next()) { tempCOunt ++; UserVO returnVO = new UserVO(); returnVO.setAppUsrId(rs.getInt("APPL_USR_ID")); returnVO.setAppUsrNm(rs.getString("APPL_USR_NM")); returnVO.setAppUsrFirstNm(rs.getString("APPL_USR_FRST_NM")); returnVO.setAppUsrLastNm(rs.getString("APPL_USR_LST_NM")); if (rs.getString("ACCESS_ROLE_CD")!=null && rs.getString("ACCESS_ROLE_CD").trim().equalsIgnoreCase(CAPConstants.ADMINISTRATOR_ROLE_CD)) returnVO.setApplicationLevelRole("Administrator"); else if (rs.getString("ACCESS_ROLE_CD")!=null && rs.getString("ACCESS_ROLE_CD").trim().equalsIgnoreCase(CAPConstants.MAINTAINER_ROLE_CD)) returnVO.setApplicationLevelRole("Maintainer"); else if (rs.getString("ACCESS_ROLE_CD")!=null && rs.getString("ACCESS_ROLE_CD").trim().equalsIgnoreCase(CAPConstants.VIEWER_ROLE_CD)) returnVO.setApplicationLevelRole("Viewer"); else returnVO.setApplicationLevelRole("None"); returnList.add(returnVO); } System.out.println("Count >>>>>>>>>>>>>>>>>>> "+tempCOunt); userVO.setReturnListFromDB(returnList); } else { int rowcount = 0; if (rs.last()) { rowcount = rs.getRow(); rs.beforeFirst(); // not rs.first() because the rs.next() below will move on, missing the first element } userVO.setTotalRecordCount(rowcount); System.out.println("Total count of the records to be used for pagination >> "+rowcount); rowcount = 0; while(rs!=null && rs.next()) { rowcount ++; UserVO returnVO = new UserVO(); returnVO.setAppUsrId(rs.getInt("APPL_USR_ID")); returnVO.setAppUsrNm(rs.getString("APPL_USR_NM")); returnVO.setAppUsrFirstNm(rs.getString("APPL_USR_FRST_NM")); returnVO.setAppUsrLastNm(rs.getString("APPL_USR_LST_NM")); if (rs.getString("ACCESS_ROLE_CD")!=null && rs.getString("ACCESS_ROLE_CD").trim().equalsIgnoreCase(CAPConstants.ADMINISTRATOR_ROLE_CD)) returnVO.setApplicationLevelRole("Administrator"); else if (rs.getString("ACCESS_ROLE_CD")!=null && rs.getString("ACCESS_ROLE_CD").trim().equalsIgnoreCase(CAPConstants.MAINTAINER_ROLE_CD)) returnVO.setApplicationLevelRole("Maintainer"); else if (rs.getString("ACCESS_ROLE_CD")!=null && rs.getString("ACCESS_ROLE_CD").trim().equalsIgnoreCase(CAPConstants.VIEWER_ROLE_CD)) returnVO.setApplicationLevelRole("Viewer"); else returnVO.setApplicationLevelRole("None"); returnList.add(returnVO); System.out.println("Row count >>"+rowcount); if(rowcount == CAPConstants.PAGINATION_MAX_VALUE) break; } rowcount = 0; userVO.setReturnListFromDB(returnList); } System.out.println("returnList >>"+returnList); return userVO; } catch (Throwable e) { e.printStackTrace(); logger.writeToTivoliAlertLog(className, CAPConstants.ERROR, methodName, userVO.getAppUsrNm(), "Error occured while trying to fetch application user details. Printing stack trace to the log for analysis..", e); throw new CAPDAOException("Error occured while trying to fetch application user details.",CAPException.SPEXECUTION_ERROR_CODE); } finally{ closeTransactionAndSession(session,transaction); } } MYSQL Query - SELECT APPL_USR_ID,APPL_USR_NM,APPL_USR_FRST_NM, APPL_USR_LST_NM,ACCESS_ROLE_CD FROM APPL_USR WHERE APPL_USR_NM LIKE '%' AND APPL_USR_FRST_NM LIKE '%' AND APPL_USR_LST_NM LIKE '%' AND APPL_USR_ID != 1 ORDER BY APPL_USR_ID LIMIT 10, 10

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• Passing ActionListeners in Java, pack()

  - by Crystal

  Two questions. First question is I'm trying to create a simple form that when you press a button, it adds a Person object to the ArrayList. However, since I am not used to GUIs, I tried creating one and am first just trying to get the user input from the JTextField, create an ActionListener object of the appropriate type, so once that works, then I can pass in all the JTextField inputs to create my Person object. Unfortunately, I am not getting any data when I type in something to the firstName JTextField and was wondering if someone could look at my code below. import java.awt.*; import java.awt.event.*; import javax.swing.*; import java.util.List; import java.util.ArrayList; public class AddressBook { public static void main(String[] args) { EventQueue.invokeLater(new Runnable() { public void run() { AddressBookFrame frame = new AddressBookFrame(); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); JMenuBar menuBar = new JMenuBar(); frame.setJMenuBar(menuBar); JMenu fileMenu = new JMenu("File"); JMenuItem openItem = new JMenuItem("Open"); JMenuItem saveItem = new JMenuItem("Save"); JMenuItem saveAsItem = new JMenuItem("Save As"); JMenuItem printItem = new JMenuItem("Print"); JMenuItem exitItem = new JMenuItem("Exit"); fileMenu.add(openItem); fileMenu.add(saveItem); fileMenu.add(saveAsItem); fileMenu.add(printItem); fileMenu.add(exitItem); menuBar.add(fileMenu); JMenu editMenu = new JMenu("Edit"); JMenuItem newItem = new JMenuItem("New"); JMenuItem editItem = new JMenuItem("Edit"); JMenuItem deleteItem = new JMenuItem("Delete"); JMenuItem findItem = new JMenuItem("Find"); JMenuItem firstItem = new JMenuItem("First"); JMenuItem previousItem = new JMenuItem("Previous"); JMenuItem nextItem = new JMenuItem("Next"); JMenuItem lastItem = new JMenuItem("Last"); editMenu.add(newItem); editMenu.add(editItem); editMenu.add(deleteItem); editMenu.add(findItem); editMenu.add(firstItem); editMenu.add(previousItem); editMenu.add(nextItem); editMenu.add(lastItem); menuBar.add(editMenu); JMenu helpMenu = new JMenu("Help"); JMenuItem documentationItem = new JMenuItem("Documentation"); JMenuItem aboutItem = new JMenuItem("About"); helpMenu.add(documentationItem); helpMenu.add(aboutItem); menuBar.add(helpMenu); frame.setVisible(true); } }); } } class AddressBookFrame extends JFrame { public AddressBookFrame() { setLayout(new BorderLayout()); setTitle("Address Book"); setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT); AddressBookToolBar toolBar = new AddressBookToolBar(); add(toolBar, BorderLayout.NORTH); AddressBookStatusBar aStatusBar = new AddressBookStatusBar("5"); add(aStatusBar, BorderLayout.SOUTH); AddressBookForm form = new AddressBookForm(); add(form, BorderLayout.CENTER); } public static final int DEFAULT_WIDTH = 500; public static final int DEFAULT_HEIGHT = 500; } /* Create toolbar buttons and add buttons to toolbar */ class AddressBookToolBar extends JPanel { public AddressBookToolBar() { setLayout(new FlowLayout(FlowLayout.LEFT)); JToolBar bar = new JToolBar(); JButton newButton = new JButton("New"); JButton editButton = new JButton("Edit"); JButton deleteButton = new JButton("Delete"); JButton findButton = new JButton("Find"); JButton firstButton = new JButton("First"); JButton previousButton = new JButton("Previous"); JButton nextButton = new JButton("Next"); JButton lastButton = new JButton("Last"); bar.add(newButton); bar.add(editButton); bar.add(deleteButton); bar.add(findButton); bar.add(firstButton); bar.add(previousButton); bar.add(nextButton); bar.add(lastButton); add(bar); } } /* Creates the status bar string */ class AddressBookStatusBar extends JPanel { public AddressBookStatusBar(String statusBarString) { setLayout(new FlowLayout(FlowLayout.LEFT)); this.statusBarString = new JLabel("Total number of people: " + statusBarString); add(this.statusBarString); } private JLabel statusBarString; private int totalContacts; } class AddressBookForm extends JPanel { public AddressBookForm() { this.setLayout(new GridLayout(2, 1)); JPanel formPanel = new JPanel(); formPanel.setLayout(new GridLayout(4, 2)); JTextField firstName = new JTextField(20); JTextField lastName = new JTextField(20); JTextField telephone = new JTextField(20); JTextField email = new JTextField(20); JLabel firstNameLabel = new JLabel("First Name: ", JLabel.LEFT); formPanel.add(firstNameLabel); formPanel.add(firstName); JLabel lastNameLabel = new JLabel("Last Name: ", JLabel.LEFT); formPanel.add(lastNameLabel); formPanel.add(lastName); JLabel telephoneLabel = new JLabel("Telephone: ", JLabel.LEFT); formPanel.add(telephoneLabel); formPanel.add(telephone); JLabel emailLabel = new JLabel("Email: ", JLabel.LEFT); formPanel.add(emailLabel); formPanel.add(email); add(formPanel); JPanel buttonPanel = new JPanel(); JButton insertButton = new JButton("Insert"); JButton displayButton = new JButton("Display"); // create button actions AddressBookManager insertAction = new AddressBookManager(firstName.getText()); insertButton.addActionListener(insertAction); buttonPanel.add(insertButton); buttonPanel.add(displayButton); add(buttonPanel); } private List<Person> addressList = new ArrayList<Person>(); private class AddressBookManager implements ActionListener { public AddressBookManager(String text) { // addressList.add( setName(text); System.out.println("Test" + text); } public void actionPerformed(ActionEvent e) { System.out.println("Hello" + name); } public void setName(String name) { this.name = name; } private String name; } } Second question is, how do I make my form not take up the whole center space. I don't like the stretch look and was hoping the JTextFields could be just one line long, not a big box. Same thing with the buttons. Any thoughts? Thanks.

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• The first day of JavaOne is already over!

  - by delabassee

  In the past Sunday used to be a more relaxing day with ‘just’ some JavaOne activities going on. Sunday used to be a soft day to prepare yourself for an exhausting week. This is now over as JavaOne is expanding; Sunday is now an integral part of the conference. One of the side effect of this extra day is that some activities related to JavaOne and OpenWorld such as MySQL Connect are being push to start a day earlier on Saturday (can you spot the pattern here?). On the GlassFish front, Sunday was a very busy day! It started at the Moscone Center with the annual GlassFish Community Event where the Java EE 7 and GF 4 roadmaps were presented and discussed. During the event, different GlassFish users such as ZeroTurnaround (the JRebel guys), Grupo RBS and IDR Solutions shared their views on GF, why they like GF but also what could be improved. The event was also a forum for the GF community to exchange with some of the key Java EE / GlassFish Oracle Executives and the different GF team members. The Strategy keynote and the Technical keynote were held in the Masonic Auditorium later in the after-noon. Oracle executives have presented the plans for Java SE, Java FX and Java EE. As on-demand replays will be available soon, I will not summarize several hours of content but here are some personal takeaways from those keynotes. Modularity Modularity is a big deal. We know by now that Project Jigsaw will not be ready for Java SE 8 but in any case, it is already possible (and encouraged) to test Jigsaw today. In the future, Java EE plan to rely on the modularity features provided by Java SE, so Project Jigsaw is also relevant for Java EE developers. Shorter term, to cover some of the modular requirements, Java SE will adopt the approach that was used for Java EE 6 and the notion of Profiles. This approach does not define a module system per say; Profiles is a way to clearly define different subsets of Java SE to fulfill different needs (e.g. the full JRE is not required for a headless application). The introduction of different Profiles, from the Base profile (10mb) to the Full Profile (+50mb), has been proposed for Java SE 8. Embedded Embedded is a strong theme going forward for the Java Plaform. There is now a dedicated program : Java Embedded @ JavaOne Java by nature (e.g. platform independence, built-in security, ability easily talks to any back-end systems, large set of skills available on the market, etc.) is probably the most suited platform for the Internet of Things. You can quickly be up-to-speed and develop services and applications for that space just by using your current Java skills. All you need to start developing on ARM is a 35$ Raspberry Pi ARM board (25$ if you are cheap and can live without an ethernet connection) and the recently released JDK for Linux/ARM. Obviously, GlassFish runs on Raspberry Pi. If you wan to go further in the embedded space, you should take a look Java SE Embedded, an optimized, low footprint, Java environment that support the major embedded architectures (ARM, PPC and x86). Finally, Oracle has recently introduced Java Embedded Suite, a new solution that brings modern middleware capabilities to the embedded space. Java Embedded Suite is an optimized solution that leverage Java SE Embedded but also GlassFish, Jersey and JavaDB to deploy advanced value added capabilities (eg. sensor data filtering and) deeper in the network, closer to the devices. JavaFX JavaFX is going strong! Starting from Java SE 7u6, JavaFX is bundled with the JDK. JavaFX is now available for all the major desktop platforms (Windows, Linux and Mac OS X). JavaFX is now also available, in developer preview, for low end device running Linux/ARM. During the keynote, JavaFX was shown running on a Raspberry Pi! And as announced during the keynote, JavaFX should be fully open-sourced by the end of the year; contributions are welcome!. There is a strong momentum around JavaFX, it’s the ideal client solution for the Java platform. A client layer that works perfectly with GlassFish on the back-end. If you were not convince by JavaFX, it’s time to reconsider it! As an old Chinese proverb say “One tweet is worth a thousand words!” HTML5, Project Avatar and Java EE 7 HTML5 got a lot of airtime too, it was covered during the Java EE 7 section of the keynote. Some details about Project Avatar, Oracle’s incubator project for a TSA (Thin Server Architecture) solution, were diluted and shown during the keynote. On the tooling side, Project Easel running on NetBeans 7.3 beta was demo’ed, including a cool NetBeans debugging session running in Chrome! HTML 5, Project Avatar and Java EE 7 deserve separate posts... Feedback We need your feedback! There are many projects, JSRs and products cooking : GlassFish 4, Project Jigsaw, Concurrency Utilities for Java EE (JSR 236), OpenJFX, OpenJDK to name just a few. Those projects, those specifications will have a profound impact on the Java platform for the years to come! So if you have the opportunity, download, install, learn, tests them and give feedback! Remember, you can "Make the Future Java!" Finally, the traditional GlassFish Party at the Thirsty Bear concluded the first JavaOne day. This party is another place where the community can freely exchange with the GlassFish team in a more relaxed, more friendly (but sometime more noisy) atmosphere. Arun has posted a set of pictures to reflect the atmosphere of the keynotes and the GlassFish party. You can find more details on the others Java EE and GlassFish activities here.

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• create fixed length flat file with Java

  - by Leslie

  I have a process that currently runs in a Delphi application that I wrote and I need to convert it to a Java process that will run on our web application. Basically our State Financial (legacy) system requires this file in a specific output. In Delphi it is like this: procedure CreateSHAREJournalFile(AppDate : string; ClassCode : string; BudgetRef : String; AccountNumber : string; FYEStep : integer); var GLFileInfo : TStrings; MPayFormat, HPayFormat, TPayFormat : string;<br> const<br> //this is the fixed length format for each item in the file<br> HeaderFormat = '%-1s%-5s%-10s%-8s%-12s%-10s%-21s%-3s%-71s%-3s%-20s%-1s';<br> DetailFormat = '%-1s%-5s%-9s%-10s%-10s%-10s%-10s%-8s%-6s%-5s%-5s%-5s%-8s%-25s%-10s%-60s%-28s%-66s%-28s';<br> begin<br> try<br>//get the data from the query<br> with dmJMS.qryShare do<br> begin<br> SQL.Clear;<br> SQL.Add('SELECT SUM(TOTHRPAY) As HourPay, SUM(TOTMLPAY) As MilePay, SUM(TOTALPAY) AS TotalPay FROM JMPCHECK INNER JOIN JMPMAIN ON JMPCHECK.JURNUM = JMPMAIN.JURNUM WHERE PANELID LIKE ''' + Copy(AppDate, 3, 6) + '%'' ');<br> if FYEStep > -1 then<br> SQL.Add('AND WARRANTNO = ' + QUotedStr(IntToStr(FYEStep)));<br> Active := True;<br> //assign totals to variables so they can be padded with leading zeros<br> MPayFormat := FieldByName('MilePay').AsString;<br> while length(MPayFormat) < 28 do <br>MPayFormat := '0' + MPayFormat;<br> HPayFormat := FieldByName('HourPay').AsString;<br> while length(HPayFormat) < 28 do <br>HPayFormat := '0' + HPayFormat;<br> TPayFormat := Format('%f' ,[(FieldByName('TotalPay').AsCurrency)]);<br> while length(TPayFormat) < 27 do<br> TPayFormat := '0' + TPayFormat;<br> TPayFormat := '-' + TPayFormat;<br> //create a TStringlist to put each line item into<br> GLFileInfo := TStringList.Create;<br> //add header info using HeaderFormat defined above<br> GLFileInfo.Add(Format(HeaderFormat, ['H', '21801', 'NEXT', FormatDateTime('MMDDYYYY', Today), '', 'ACTUALS', '', 'EXT', '', 'EXT', '', 'N']));<br> //add detail info using DetailFormat defined above<br> GLFileInfo.Add(Format(DetailFormat, ['L', '21801', '1', 'ACTUALS', AccountNumber, '', '1414000000', '111500', '', '01200', ClassCode, '', BudgetRef, '', AccountNumber + '0300', '', MPayFormat, '', MPayFormat]));<br> GLFileInfo.Add(Format(DetailFormat, ['L', '21801', '2', 'ACTUALS', AccountNumber, '', '1414000000', '111500', '', '01200', ClassCode, '', BudgetRef, '', AccountNumber + '0100', '', HPayFormat, '', HPayFormat]));<br> GLFileInfo.Add(Format(DetailFormat, ['L', '21801', '3', 'ACTUALS', '101900', '', '1414000000', '111500', '', '01200', ClassCode, '', BudgetRef, '', '', '', TPayFormat, '', TPayFormat]));<br> //save TStringList to text file<br> GLFileINfo.SaveToFile(ExtractFilePath(Application.ExeName) + 'FileTransfer\GL_' + formatdateTime('mmddyy', Today) + SequenceID + '24400' + '.txt');<br> end;<br> finally<br> GLFileINfo.Free;<br> end; end; is there an equivalent in Java for the Format option? Or the TStringList that saves to a text file? Thanks for any information....haven't done a lot of Java programming! Leslie

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• How to read URDU from url and show it to your mobile using java Me

  - by Basit

  HI, Hope you all will be fine. Actually I m facing a problem. Actually i am using Google translation API. What my application does it connect to CGI-script, i pass value to it using GET then the CGI script connect to Google API, Translate the mesage from english to Urdu and then i retreive it.Here is the code [Java] import java.io.*; import javax.microedition.io.*; import javax.microedition.lcdui.*; import javax.microedition.midlet.*; /** * An example MIDlet to invoke a CGI script (GET method). */ public class InvokeCgiMidlet1 extends MIDlet { private Display display; String url = "http://xxx.xxx.xx.xxx/cgi-bin/api/GT/GT_Send_Msg.cgi?message=my%20name%20is%20basit"; public InvokeCgiMidlet1() { display = Display.getDisplay(this); } /** * Initialization. Invoked when we activate the MIDlet. */ public void startApp() { try { getGrade(url); } catch (IOException e) { System.out.println("IOException " + e); e.printStackTrace(); } } /** * Pause, discontinue .... */ public void pauseApp() { } /** * Destroy must cleanup everything. */ public void destroyApp(boolean unconditional) { } /** * Retrieve a grade.... */ void getGrade(String url) throws IOException { HttpConnection c = null; InputStream is = null; OutputStream os = null; StringBuffer b = new StringBuffer(); TextBox t = null; String response; try { c = (HttpConnection)Connector.open(url, Connector.READ_WRITE); c.setRequestMethod(HttpConnection.GET); c.setRequestProperty("User-Agent","Profile/MIDP-1.0 Confirguration/CLDC-1.0"); c.setRequestProperty("Content-Type","application/x-www-form-urlencoded"); c.setRequestProperty("User-Agent","Profile/MIDP-2.0 Configuration/CLDC-1.1"); c.setRequestProperty("Accept-Charset","UTF-8;q=0.7,*;q=0.7"); c.setRequestProperty("Accept-Encoding","gzip, deflate"); c.setRequestProperty("Accept","text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5"); c.setRequestProperty("Content-Language", "en-EN"); os = c.openOutputStream(); Reader r = new InputStreamReader(c.openDataInputStream(), "UTF-8"); int ch; while ((ch = r.read()) != -1) { b.append((char) ch ); //System.out.println((char)ch + "->" + ch + "->" + ch); } t = new TextBox("Final Grades", b.reverse().toString(), 1024, 0); } finally { if(is!= null) { is.close(); } if(os != null) { os.close(); } if(c != null) { c.close(); } } display.setCurrent(t); } } [/Java] The problem is as i told you that the translated text is in Urdu. So when it appear on screen each character is separate like this. ? ?? ? ? ?? . Because i read character by character I want it to appear in proper form like this ??????? So how can i do this. Is there font rendering required. If yes then how can i do it or any other method please hep me. Thanks

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• context.getContextResolved appliaction stopped - begginner in java

  - by Szymad

  I have a problem with my app. I'm trying to execute query, but app stops every time. This error occurs while trying to execute query. I'm learing from Android Pro 3 book, but code presented in this book is deprecated. package com.example.contactsabuout; import android.net.Uri; import android.os.Bundle; import android.provider.Contacts; import android.provider.ContactsContract; import android.app.Activity; import android.database.Cursor; import android.util.Log; import android.content.Context; import android.view.Menu; import android.view.View; import android.widget.TextView; public class MainActivity extends Activity { private static Context context; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); MainActivity.context = getApplicationContext(); Log.v("INFO", "Completed: onCreate."); } public static Context getAppContext() { return MainActivity.context; } public void doQuery(View view) { Uri peopleBaseUri = ContactsContract.Contacts.CONTENT_URI; Log.v("II","Button clicked."); Log.v("II", "Uri for ContactsContract.Contacts: " + peopleBaseUri); Context context = getAppContext(); Log.v("II", "Got context: " + context); Cursor cur; Log.v("II", "Created cursor: cur"); cur = context.getContentResolver().query(peopleBaseUri, null, null, null, null); } @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.activity_main, menu); return true; } } FROM LogCat 10-28 17:45:02.513: V/INFO(4677): Completed: onCreate. 10-28 17:45:02.613: D/libEGL(4677): loaded /system/lib/egl/libGLES_android.so 10-28 17:45:02.653: D/libEGL(4677): loaded /system/lib/egl/libEGL_adreno200.so 10-28 17:45:02.723: D/libEGL(4677): loaded /system/lib/egl/libGLESv1_CM_adreno200.so 10-28 17:45:02.723: D/libEGL(4677): loaded /system/lib/egl/libGLESv2_adreno200.so 10-28 17:45:03.014: I/Adreno200-EGLSUB(4677): <ConfigWindowMatch:2078>: Format RGBA_8888. 10-28 17:45:03.054: D/OpenGLRenderer(4677): Enabling debug mode 0 10-28 17:45:03.254: D/OpenGLRenderer(4677): has fontRender patch 10-28 17:45:03.274: D/OpenGLRenderer(4677): has fontRender patch 10-28 17:45:12.873: V/II(4677): Button clicked. 10-28 17:45:12.873: V/II(4677): Uri for ContactsContract.Contacts: content://com.android.contacts/contacts, rest will be null 10-28 17:45:12.873: V/II(4677): Got context: android.app.Application@40d83d90 10-28 17:45:12.873: V/II(4677): Created cursor: cur 10-28 17:45:12.933: D/AndroidRuntime(4677): Shutting down VM 10-28 17:45:12.933: W/dalvikvm(4677): threadid=1: thread exiting with uncaught exception (group=0x40aaf228) 10-28 17:45:12.953: E/AndroidRuntime(4677): FATAL EXCEPTION: main 10-28 17:45:12.953: E/AndroidRuntime(4677): java.lang.IllegalStateException: Could not execute method of the activity 10-28 17:45:12.953: E/AndroidRuntime(4677): at android.view.View$1.onClick(View.java:3071) 10-28 17:45:12.953: E/AndroidRuntime(4677): at android.view.View.performClick(View.java:3538) 10-28 17:45:12.953: E/AndroidRuntime(4677): at android.view.View$PerformClick.run(View.java:14330) 10-28 17:45:12.953: E/AndroidRuntime(4677): at android.os.Handler.handleCallback(Handler.java:608) 10-28 17:45:12.953: E/AndroidRuntime(4677): at android.os.Handler.dispatchMessage(Handler.java:92) 10-28 17:45:12.953: E/AndroidRuntime(4677): at android.os.Looper.loop(Looper.java:156) 10-28 17:45:12.953: E/AndroidRuntime(4677): at android.app.ActivityThread.main(ActivityThread.java:4977) 10-28 17:45:12.953: E/AndroidRuntime(4677): at java.lang.reflect.Method.invokeNative(Native Method) 10-28 17:45:12.953: E/AndroidRuntime(4677): at java.lang.reflect.Method.invoke(Method.java:511) 10-28 17:45:12.953: E/AndroidRuntime(4677): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784) 10-28 17:45:12.953: E/AndroidRuntime(4677): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551) 10-28 17:45:12.953: E/AndroidRuntime(4677): at dalvik.system.NativeStart.main(Native Method) 10-28 17:45:12.953: E/AndroidRuntime(4677): Caused by: java.lang.reflect.InvocationTargetException 10-28 17:45:12.953: E/AndroidRuntime(4677): at java.lang.reflect.Method.invokeNative(Native Method) 10-28 17:45:12.953: E/AndroidRuntime(4677): at java.lang.reflect.Method.invoke(Method.java:511) 10-28 17:45:12.953: E/AndroidRuntime(4677): at android.view.View$1.onClick(View.java:3066) 10-28 17:45:12.953: E/AndroidRuntime(4677): ... 11 more 10-28 17:45:12.953: E/AndroidRuntime(4677): Caused by: java.lang.SecurityException: Permission Denial: reading com.android.providers.contacts.HtcContactsProvider2 uri content://com.android.contacts/contacts from pid=4677, uid=10155 requires android.permission.READ_CONTACTS 10-28 17:45:12.953: E/AndroidRuntime(4677): at android.os.Parcel.readException(Parcel.java:1332) 10-28 17:45:12.953: E/AndroidRuntime(4677): at android.database.DatabaseUtils.readExceptionFromParcel(DatabaseUtils.java:182) 10-28 17:45:12.953: E/AndroidRuntime(4677): at android.database.DatabaseUtils.readExceptionFromParcel(DatabaseUtils.java:136) 10-28 17:45:12.953: E/AndroidRuntime(4677): at android.content.ContentProviderProxy.query(ContentProviderNative.java:406) 10-28 17:45:12.953: E/AndroidRuntime(4677): at android.content.ContentResolver.query(ContentResolver.java:315) 10-28 17:45:12.953: E/AndroidRuntime(4677): at com.example.contactsabuout.MainActivity.doQuery(MainActivity.java:47) 10-28 17:45:12.953: E/AndroidRuntime(4677): ... 14 more I'm trying to learn android.

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• How to play audio in Java Application

  - by user577829

  I'm making a java application and I need to play audio. I'm playing mainly small sound files of my cannon firing (its a cannon shooting game) and the projectiles exploding, though I plan on having looping background music. I have found two different methods to accomplish this, but both don't work how I want. The first method is literally a method: public void playSoundFile(File file) {//http://java.ittoolbox.com/groups/technical-functional/java-l/sound-in-an-application-90681 try { //get an AudioInputStream AudioInputStream ais = AudioSystem.getAudioInputStream(file); //get the AudioFormat for the AudioInputStream AudioFormat audioformat = ais.getFormat(); System.out.println("Format: " + audioformat.toString()); System.out.println("Encoding: " + audioformat.getEncoding()); System.out.println("SampleRate:" + audioformat.getSampleRate()); System.out.println("SampleSizeInBits: " + audioformat.getSampleSizeInBits()); System.out.println("Channels: " + audioformat.getChannels()); System.out.println("FrameSize: " + audioformat.getFrameSize()); System.out.println("FrameRate: " + audioformat.getFrameRate()); System.out.println("BigEndian: " + audioformat.isBigEndian()); //ULAW format to PCM format conversion if ((audioformat.getEncoding() == AudioFormat.Encoding.ULAW) || (audioformat.getEncoding() == AudioFormat.Encoding.ALAW)) { AudioFormat newformat = new AudioFormat(AudioFormat.Encoding.PCM_SIGNED, audioformat.getSampleRate(), audioformat.getSampleSizeInBits() * 2, audioformat.getChannels(), audioformat.getFrameSize() * 2, audioformat.getFrameRate(), true); ais = AudioSystem.getAudioInputStream(newformat, ais); audioformat = newformat; } //checking for a supported output line DataLine.Info datalineinfo = new DataLine.Info(SourceDataLine.class, audioformat); if (!AudioSystem.isLineSupported(datalineinfo)) { //System.out.println("Line matching " + datalineinfo + " is not supported."); } else { //System.out.println("Line matching " + datalineinfo + " is supported."); //opening the sound output line SourceDataLine sourcedataline = (SourceDataLine) AudioSystem.getLine(datalineinfo); sourcedataline.open(audioformat); sourcedataline.start(); //Copy data from the input stream to the output data line int framesizeinbytes = audioformat.getFrameSize(); int bufferlengthinframes = sourcedataline.getBufferSize() / 8; int bufferlengthinbytes = bufferlengthinframes * framesizeinbytes; byte[] sounddata = new byte[bufferlengthinbytes]; int numberofbytesread = 0; while ((numberofbytesread = ais.read(sounddata)) != -1) { int numberofbytesremaining = numberofbytesread; sourcedataline.write(sounddata, 0, numberofbytesread); } } } catch (Exception e) { e.printStackTrace(); } } The problem with this is that my entire program stops until the sound file is finished, or at least nearly finished. The second method is this: File file = new File("Launch1.wav"); AudioClip clip; try { clip = JApplet.newAudioClip(file.toURL()); clip.play(); } catch (Exception e) { e.getMessage(); } The problem I have here is that every time the sound file ends early or doesn't play at all depending on where I place the code. Is their any way to play sound without the above mentioned problems? Am I doing something wrong? Any help is greatly appreciated.

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• Java, LDAP: Make it not ignore blank passwords?

  - by Steve

  I'm maintaining some legacy Java LDAP code. I know next to nothing about LDAP. The program below basically just sends the userid and password to the LDAP server, receives notification back if the credentials are good. If so, it prints out the LDAP attributes received from the LDAP server, if not it prints out an exception. All works well if a bad password is given. An "invalid credentials" exception gets thrown. However, if a blank password is sent to the LDAP Server, authentication will still happen, LDAP attributes will still be returned. Is this unhappy situation due to the LDAP server allowing blank passwords, or does the code below need to be adjusted such a blank password will get fed to the LDAP server in such a way so it will get rejected? I do have data validation in place. I took it off in a testing environment to solve another issue and noticed this problem. I would prefer not to have this problem underneath the data validation. Thanks much in advance for any information import javax.naming.*; import javax.naming.directory.*; import java.util.*; import java.sql.*; public class LDAPTEST { public static void main(String args[]) { String lcf = "com.sun.jndi.ldap.LdapCtxFactory"; String ldapurl = "ldaps://ldap-cit.smew.acme.com:636/o=acme.com"; String loginid = "George.Jetson"; String password = ""; DirContext ctx = null; Hashtable env = new Hashtable(); Attributes attr = null; Attributes resultsAttrs = null; SearchResult result = null; NamingEnumeration results = null; int iResults = 0; int iAttributes = 0; env.put(Context.INITIAL_CONTEXT_FACTORY, lcf); env.put(Context.PROVIDER_URL, ldapurl); env.put(Context.SECURITY_PROTOCOL, "ssl"); env.put(Context.SECURITY_AUTHENTICATION, "simple"); env.put(Context.SECURITY_PRINCIPAL, "uid=" + loginid + ",ou=People,o=acme.com"); env.put(Context.SECURITY_CREDENTIALS, password); try { ctx = new InitialDirContext(env); attr = new BasicAttributes(true); attr.put(new BasicAttribute("uid",loginid)); results = ctx.search("ou=People",attr); while (results.hasMore()) { result = (SearchResult)results.next(); resultsAttrs = result.getAttributes(); for (NamingEnumeration enumAttributes = resultsAttrs.getAll(); enumAttributes.hasMore();) { Attribute a = (Attribute)enumAttributes.next(); System.out.println("attribute: " + a.getID() + " : " + a.get().toString()); iAttributes++; }// end for loop iResults++; }// end while loop System.out.println("Records == " + iResults + " Attributes: " + iAttributes); }// end try catch (Exception e) { e.printStackTrace(); } }// end function main() }// end class LDAPTEST

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• Java -Android. Parser problem

  - by Kano

  I am making a very simple app with an RSS reader. The reader works great, but it's only giving me the title, and i want the description too. I'am very new to android, and I have tried a lot of things, but I can't get it to work. I've found a lot of parsers but they are to complicated for me to understand, so I was hoping to find a simple solution, since it's only title and description i want. Can anyone help me? import java.io.IOException; import java.net.MalformedURLException; import java.net.URL; import javax.xml.parsers.ParserConfigurationException; import javax.xml.parsers.SAXParser; import javax.xml.parsers.SAXParserFactory; import org.xml.sax.Attributes; import org.xml.sax.InputSource; import org.xml.sax.SAXException; import org.xml.sax.XMLReader; import org.xml.sax.helpers.DefaultHandler; import android.app.Activity; import android.os.Bundle; import android.widget.TextView; public class NyhedActivity extends Activity { String streamTitle = ""; @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); setContentView(R.layout.nyheder); TextView result = (TextView)findViewById(R.id.result); try { URL rssUrl = new URL("http://tv2sport.dk/rss/*/*/*/248/*/*"); SAXParserFactory mySAXParserFactory = SAXParserFactory.newInstance(); SAXParser mySAXParser = mySAXParserFactory.newSAXParser(); XMLReader myXMLReader = mySAXParser.getXMLReader(); RSSHandler myRSSHandler = new RSSHandler(); myXMLReader.setContentHandler(myRSSHandler); InputSource myInputSource = new InputSource(rssUrl.openStream()); myXMLReader.parse(myInputSource); result.setText(streamTitle); } catch (MalformedURLException e) { // TODO Auto-generated catch block e.printStackTrace(); result.setText("Cannot connect RSS!"); } catch (ParserConfigurationException e) { // TODO Auto-generated catch block e.printStackTrace(); result.setText("Cannot connect RSS!"); } catch (SAXException e) { // TODO Auto-generated catch block e.printStackTrace(); result.setText("Cannot connect RSS!"); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); result.setText("Cannot connect RSS!"); } } private class RSSHandler extends DefaultHandler { final int stateUnknown = 0; final int stateTitle = 1; int state = stateUnknown; int numberOfTitle = 0; String strTitle = ""; String strElement = ""; @Override public void startDocument() throws SAXException { // TODO Auto-generated method stub strTitle = "Nyheder fra "; } @Override public void endDocument() throws SAXException { // TODO Auto-generated method stub strTitle += ""; streamTitle = "" + strTitle; } @Override public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException { // TODO Auto-generated method stub if (localName.equalsIgnoreCase("title")) { state = stateTitle; strElement = ""; numberOfTitle++; } else { state = stateUnknown; } } @Override public void endElement(String uri, String localName, String qName) throws SAXException { // TODO Auto-generated method stub if (localName.equalsIgnoreCase("title")) { strTitle += strElement + "\n"+"\n"; } state = stateUnknown; } @Override public void characters(char[] ch, int start, int length) throws SAXException { // TODO Auto-generated method stub String strCharacters = new String(ch, start, length); if (state == stateTitle) { strElement += strCharacters; } } } }

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• Can java do a timer on command line by overwriting the time on the same line?

  - by javaLearner.java

  HI I am a new java programmer (very new). What I want to do/test is (not sure if its recommendable or doable?), we know that System.out.println("Message"); will output the "Message" in command prompt. Is it possible to display the current time, without having to repeatly use the system.out.println()? Name, like instead of displaying: 10:00:01 10:00:02 10:00:03 I wand to have liek this: 10:00:0X where X will continue counting

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• Explanation of the definition of interface inheritance as described in GoF book

  - by Geek

  I am reading the first chapter of the Gof book. Section 1.6 discusses about class vs interface inheritance: Class versus Interface Inheritance It's important to understand the difference between an object's class and its type. An object's class defines how the object is implemented.The class defines the object's internal state and the implementation of its operations.In contrast,an object's type only refers to its interface--the set of requests on which it can respond. An object can have many types, and objects of different classes can have the same type. Of course, there's a close relationship between class and type. Because a class defines the operations an object can perform, it also defines the object's type . When we say that an object is an instance of a class, we imply that the object supports the interface defined by the class. Languages like c++ and Eiffel use classes to specify both an object's type and its implementation. Smalltalk programs do not declare the types of variables; consequently,the compiler does not check that the types of objects assigned to a variable are subtypes of the variable's type. Sending a message requires checking that the class of the receiver implements the message, but it doesn't require checking that the receiver is an instance of a particular class. It's also important to understand the difference between class inheritance and interface inheritance (or subtyping). Class inheritance defines an object's implementation in terms of another object's implementation. In short, it's a mechanism for code and representation sharing. In contrast,interface inheritance(or subtyping) describes when an object can be used in place of another. I am familiar with the Java and JavaScript programming language and not really familiar with either C++ or Smalltalk or Eiffel as mentioned here. So I am trying to map the concepts discussed here to Java's way of doing classes, inheritance and interfaces. This is how I think of of these concepts in Java: In Java a class is always a blueprint for the objects it produces and what interface(as in "set of all possible requests that the object can respond to") an object of that class possess is defined during compilation stage only because the class of the object would have implemented those interfaces. The requests that an object of that class can respond to is the set of all the methods that are in the class(including those implemented for the interfaces that this class implements). My specific questions are: Am I right in saying that Java's way is more similar to C++ as described in the third paragraph. I do not understand what is meant by interface inheritance in the last paragraph. In Java interface inheritance is one interface extending from another interface. But I think the word interface has some other overloaded meaning here. Can some one provide an example in Java of what is meant by interface inheritance here so that I understand it better?

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