Search Results

Search found 5831 results on 234 pages for 'chuck final'.

Page 24/234 | < Previous Page | 20 21 22 23 24 25 26 27 28 29 30 31  | Next Page >

  • Java: immutable Stack?

    - by HH
    I chose to use Stacks and Tables before knowing Collections has immutable empty things only for Set, Map and List. Because the size of table does not change after its init: Integer[] table = new Intger[0] I can use the zero-witdh table as an empty table. But I cannot use final or empty Stack to get immutable Stack: No immutability to Stack with Final import java.io.*; import java.util.*; public class TestStack{ public static void main(String[] args) { final Stack<Integer> test = new Stack<Integer>(); Stack<Integer> test2 = new Stack<Integer>(); test.push(37707); test2.push(80437707); //WHY is there not an error to remove an elment // from FINAL stack? System.out.println(test.pop()); System.out.println(test2.pop()); } } Java Api 5 for list interface shows that Stack is an implementing class for list and arraylist, here. The java.coccurrent pkg does not have any immutable Stack data structure. From Stack to some immutable data structure How to get immutable Stack data structure? Can I box it with list? Should I switch my current implementatios from stacks to Lists to get immutable? Which immutable data structure is Very fast with about similar exec time as Stack?

    Read the article

  • How to call a .NET Webservice from Android using KSOAP2?

    - by Rajapandian
    Hai to All,I have a problem while calling the webservice,i have a .NET web service in the server and i am using KSOAP2(ksoap2-j2se-full-2.1.2) in android.While running the program i got an runtime Exception like "org.ksoap2.serialization.SoapPrimitive". I dont know what to do.Here is my code. package projects.ksoap2sample; import org.ksoap2.SoapEnvelope; import org.ksoap2.serialization.SoapObject; import org.ksoap2.serialization.SoapSerializationEnvelope; import org.ksoap2.transport.HttpTransportSE; import android.app.*; import android.os.*; import android.widget.TextView; public class ksoap2sample extends Activity { /** Called when the activity is first created. */ private static final String SOAP_ACTION = "http://tempuri.org/HelloWorld"; private static final String METHOD_NAME = "HelloWorld"; private static final String NAMESPACE = "http://tempuri.org/"; private static final String URL = "http://192.168.1.19/TestWeb/WebService.asmx"; TextView tv; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); tv=(TextView)findViewById(R.id.text1); try { SoapObject request = new SoapObject(NAMESPACE, METHOD_NAME); //request.addProperty("prop1", "myprop"); SoapSerializationEnvelope envelope = new SoapSerializationEnvelope(SoapEnvelope.VER11); envelope.dotNet=true; envelope.setOutputSoapObject(request); HttpTransportSE androidHttpTransport = new HttpTransportSE(URL); androidHttpTransport.call(SOAP_ACTION, envelope); Object result = (Object)envelope.getResponse(); String[] results = (String[]) result; tv.setText( ""+results[0]); } catch (Exception e) { tv.setText(e.getMessage()); } } } May be my code is wrong.please help me. Regards Rajapandian

    Read the article

  • In Java Concurrency In Practice by Brian Goetz, why is the Memoizer class not annotated with @ThreadSafe?

    - by dig_dug
    Java Concurrency In Practice by Brian Goetz provides an example of a efficient scalable cache for concurrent use. The final version of the example showing the implementation for class Memoizer (pg 108) shows such a cache. I am wondering why the class is not annotated with @ThreadSafe? The client, class Factorizer, of the cache is properly annotated with @ThreadSafe. The appendix states that if a class is not annotated with either @ThreadSafe or @Immutable that it should be assumed that it isn't thread safe. Memoizer seems thread-safe though. Here is the code for Memoizer: public class Memoizer<A, V> implements Computable<A, V> { private final ConcurrentMap<A, Future<V>> cache = new ConcurrentHashMap<A, Future<V>>(); private final Computable<A, V> c; public Memoizer(Computable<A, V> c) { this.c = c; } public V compute(final A arg) throws InterruptedException { while (true) { Future<V> f = cache.get(arg); if (f == null) { Callable<V> eval = new Callable<V>() { public V call() throws InterruptedException { return c.compute(arg); } }; FutureTask<V> ft = new FutureTask<V>(eval); f = cache.putIfAbsent(arg, ft); if (f == null) { f = ft; ft.run(); } } try { return f.get(); } catch (CancellationException e) { cache.remove(arg, f); } catch (ExecutionException e) { throw launderThrowable(e.getCause()); } } } }

    Read the article

  • Deleting JPA entity containing @CollectionOfElements throws ConstraintViolationException

    - by Lyle
    I'm trying to delete entities which contain lists of Integer, and I'm getting ConstraintViolationExceptions because of the foreign key on the table generated to hold the integers. It appears that the delete isn't cascading to the mapped collection. I've done quite a bit of searching, but all of the examples I've seen on how to accomplish this are in reference to a mapped collection of other entities which can be annotated; here I'm just storing a list of Integer. Here is the relevant excerpt from the class I'm storing: @Entity @Table(name="CHANGE_IDS") @GenericGenerator( name = "CHANGE_ID_GEN", strategy = "org.hibernate.id.enhanced.SequenceStyleGenerator", parameters = { @Parameter(name="sequence_name", value="course_changes_seq"), @Parameter(name="increment_size", value="5000"), @Parameter(name=" optimizer", value="pooled") } ) @NamedQueries ({ @NamedQuery( name="Changes.getByStatus", query= "SELECT c " + "FROM DChanges c " + "WHERE c.status = :status "), @NamedQuery( name="Changes.deleteByStatus", query= "DELETE " + "FROM Changes c " + "WHERE c.status = :status ") }) public class Changes { @Id @GeneratedValue(generator="CHANGE_ID_GEN") @Column(name = "ID") private final long id; @Enumerated(EnumType.STRING) @Column(name = "STATUS", length = 20, nullable = false) private final Status status; @Column(name="DOC_ID") @org.hibernate.annotations.CollectionOfElements @org.hibernate.annotations.IndexColumn(name="DOC_ID_ORDER") private List<Integer> docIds; } I'm deleting the Changes objects using a @NamedQuery: final Query deleteQuery = this.entityManager.createNamedQuery("Changes.deleteByStatus"); deleteQuery.setParameter("status", Status.POST_FLIP); final int deleted = deleteQuery.executeUpdate(); this.logger.info("Deleted " + deleted + " POST_FLIP Changes");

    Read the article

  • Renaming column in Android sqlite database results in error

    - by Apophenia Overload
    I've been modifying the Notepad tutorial for Android very subtly- all I did was rename the column from title to name: Before: public static final String KEY_TITLE = "title"; ... private static final String DATABASE_CREATE = "create table notes (_id integer primary key autoincrement, " + "title text not null, body text not null);"; After: public static final String KEY_TITLE = "name"; ... private static final String DATABASE_CREATE = "create table notes (_id integer primary key autoincrement, " + "name text not null, body text not null);"; However, it always results in this: 06-10 03:29:38.421: ERROR/AndroidRuntime(344): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.android.demo.notepad1/com.android.demo.notepad1.Notepadv1}: android.database.sqlite.SQLiteException: no such column: name: , while compiling: SELECT _id, name, body FROM notes ... 06-10 03:29:38.421: ERROR/AndroidRuntime(344): Caused by: android.database.sqlite.SQLiteException: no such column: name: , while compiling: SELECT _id, name, body FROM notes Am I failing to rename something? All I am modifying is the Exercise 1 Solution program from the Notepad tutorial.

    Read the article

  • How can I place validating constraints on my method input parameters?

    - by rcampbell
    Here is the typical way of accomplishing this goal: public void myContractualMethod(final String x, final Set<String> y) { if ((x == null) || (x.isEmpty())) { throw new IllegalArgumentException("x cannot be null or empty"); } if (y == null) { throw new IllegalArgumentException("y cannot be null"); } // Now I can actually start writing purposeful // code to accomplish the goal of this method I think this solution is ugly. Your methods quickly fill up with boilerplate code checking the valid input parameters contract, obscuring the heart of the method. Here's what I'd like to have: public void myContractualMethod(@NotNull @NotEmpty final String x, @NotNull final Set<String> y) { // Now I have a clean method body that isn't obscured by // contract checking If those annotations look like JSR 303/Bean Validation Spec, it's because I borrowed them. Unfortunitely they don't seem to work this way; they are intended for annotating instance variables, then running the object through a validator. Which of the many Java design-by-contract frameworks provide the closest functionality to my "like to have" example? The exceptions that get thrown should be runtime exceptions (like IllegalArgumentExceptions) so encapsulation isn't broken.

    Read the article

  • Is 1/0 a legal Java expression?

    - by polygenelubricants
    The following compiles fine in my Eclipse: final int j = 1/0; // compiles fine!!! // throws ArithmeticException: / by zero at run-time Java prevents many "dumb code" from even compiling in the first place (e.g. "Five" instanceof Number doesn't compile!), so the fact this didn't even generate as much as a warning was very surprising to me. The intrigue deepens when you consider the fact that constant expressions are allowed to be optimized at compile time: public class Div0 { public static void main(String[] args) { final int i = 2+3; final int j = 1/0; final int k = 9/2; } } Compiled in Eclipse, the above snippet generates the following bytecode (javap -c Div0) Compiled from "Div0.java" public class Div0 extends java.lang.Object{ public Div0(); Code: 0: aload_0 1: invokespecial #8; //Method java/lang/Object."<init>":()V 4: return public static void main(java.lang.String[]); Code: 0: iconst_5 1: istore_1 // "i = 5;" 2: iconst_1 3: iconst_0 4: idiv 5: istore_2 // "j = 1/0;" 6: iconst_4 7: istore_3 // "k = 4;" 8: return } As you can see, the i and k assignments are optimized as compile-time constants, but the division by 0 (which must've been detectable at compile-time) is simply compiled as is. javac 1.6.0_17 behaves even more strangely, compiling silently but excising the assignments to i and k completely out of the bytecode (probably because it determined that they're not used anywhere) but leaving the 1/0 intact (since removing it would cause an entirely different program semantics). So the questions are: Is 1/0 actually a legal Java expression that should compile anytime anywhere? What does JLS say about it? If this is legal, is there a good reason for it? What good could this possibly serve?

    Read the article

  • Why is my GUI unresponsive while a SwingWorker thread runs?

    - by Starchy
    Hello, I have a SwingWorker thread with an IOBound task which is totally locking up the interface while it runs. Swapping out the normal workload for a counter loop has the same result. The SwingWorker looks basically like this: public class BackupWorker extends SwingWorker<String, String> { private static String uname = null; private static String pass = null; private static String filename = null; static String status = null; BackupWorker (String uname, String pass, String filename) { this.uname = uname; this.pass = pass; this.filename = filename; } @Override protected String doInBackground() throws Exception { BackupObject bak = newBackupObject(uname,pass,filename); return "Done!"; } } The code that kicks it off lives in a class that extends JFrame: public void actionPerformed(ActionEvent event) { String cmd = event.getActionCommand(); if (BACKUP.equals(cmd)) { SwingUtilities.invokeLater(new Runnable() { public void run() { final StatusFrame statusFrame = new StatusFrame(); statusFrame.setVisible(true); SwingUtilities.invokeLater(new Runnable() { public void run () { statusFrame.beginBackup(uname,pass,filename); } }); } }); } } Here's the interesting part of StatusFrame: public void beginBackup(final String uname, final String pass, final String filename) { worker = new BackupWorker(uname, pass, filename); worker.execute(); try { System.out.println(worker.get()); } catch (InterruptedException e) { e.printStackTrace(); } catch (ExecutionException e) { e.printStackTrace(); } } } So far as I can see, everything "long-running" is handled by the worker, and everything that touches the GUI on the EDT. Have I tangled things up somewhere, or am I expecting too much of SwingWorker?

    Read the article

  • Problem when copying array of different types using Arrays.copyOf

    - by Shervin
    I am trying to create a method that pretty much takes anything as a parameter, and returns a concatenated string representation of the value with some delimiter. public static String getConcatenated(char delim, Object ...names) { String[] stringArray = Arrays.copyOf(names, names.length, String[].class); //Exception here return getConcatenated(delim, stringArray); } And the actual method public static String getConcatenated(char delim, String ... names) { if(names == null || names.length == 0) return ""; StringBuilder sb = new StringBuilder(); for(int i = 0; i < names.length; i++) { String n = names[i]; if(n != null) { sb.append(n.trim()); sb.append(delim); } } //Remove the last delim return sb.substring(0, sb.length()-1).toString(); } And I have the following JUnit test: final String two = RedpillLinproUtils.getConcatenated(' ', "Shervin", "Asgari"); Assert.assertEquals("Result", "Shervin Asgari", two); //OK final String three = RedpillLinproUtils.getConcatenated(';', "Shervin", "Asgari"); Assert.assertEquals("Result", "Shervin;Asgari", three); //OK final String four = RedpillLinproUtils.getConcatenated(';', "Shervin", null, "Asgari", null); Assert.assertEquals("Result", "Shervin;Asgari", four); //OK final String five = RedpillLinproUtils.getConcatenated('/', 1, 2, null, 3, 4); Assert.assertEquals("Result", "1/2/3/4", five); //FAIL However, the test fails on the last part with the exception: java.lang.ArrayStoreException at java.lang.System.arraycopy(Native Method) at java.util.Arrays.copyOf(Arrays.java:2763) Can someone spot the error?

    Read the article

  • Playing with bytes...need to convert from java to C#

    - by ibiza
    Hi fellow programmers, I am not used to manipulate bytes in my code and I have this piece of code that is written in Java and I would need to convert it to its C# equivalent : protected static final int putLong(final byte[] b, final int off, final long val) { b[off + 7] = (byte) (val >>> 0); b[off + 6] = (byte) (val >>> 8); b[off + 5] = (byte) (val >>> 16); b[off + 4] = (byte) (val >>> 24); b[off + 3] = (byte) (val >>> 32); b[off + 2] = (byte) (val >>> 40); b[off + 1] = (byte) (val >>> 48); b[off + 0] = (byte) (val >>> 56); return off + 8; } Thanks in advance for all your help, I am looking forward to learn from this.

    Read the article

  • CGLIB proxy error after spring bean definition loading into XmlWebApplicationContext at runtime

    - by VasylV
    I load additional singleton beans definitions at runtime from external jar file into existing XmlWebApplicationContext of my application: BeanFactory beanFactory = xmlWebApplicationContext.getBeanFactory(); DefaultListableBeanFactory defaultFactory = (DefaultListableBeanFactory)beanFactory; final URL url = new URL("external.jar"); final URL[] urls = {url}; ClassLoader loader = new URLClassLoader(urls, this.getClass().getClassLoader()); defaultFactory.setBeanClassLoader(loader); final ClassPathBeanDefinitionScanner scanner = new ClassPathBeanDefinitionScanner(defaultFactory); final DefaultResourceLoader resourceLoader = new DefaultResourceLoader(); resourceLoader.setClassLoader(loader); scanner.setResourceLoader(resourceLoader); scanner.scan("com.*"); Object bean = xmlWebApplicationContext.getBean("externalBean"); After all above xmlWebApplicationContext contains all external definitions of beans. But when i am trying to get bean from context exception is thrown: Couldn't generate CGLIB proxy for class ... I saw in debug mode that in the bean initialization process first time proxy is generated by org.springframework.aop.aspectj.autoproxy.AspectJAwareAdvisorAutoProxyCreator and than it is tried to generate proxy with org.springframework.aop.framework.autoproxy.BeanNameAutoProxyCreator but fails with mentioned exception.

    Read the article

  • How can a link within a WebView load another layout using javascript?

    - by huffmaster
    So I have 2 layout files (main.xml, featured.xml) and both each have a single WebView. When the application starts "main.xml" loads a html file into it's WebView. In this html file I have a link that calls javascript that runs code in the Activity that loaded the html. Once back in this Activity code though I try running setContentView(R.layout.featured) but it just bombs out on me. If I debug it just dies without any real error and if I run it the application just Force closes. Am I going about this correctly or should I be doing something differently? final private int MAIN = 1; final private int FEATURED = 2; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); webview = (WebView) findViewById(R.id.wvMain); webview.getSettings().setJavaScriptEnabled(true); webview.getSettings().setSupportZoom(false); webview.addJavascriptInterface(new EHJavaScriptInterface(), "eh"); webview.loadUrl("file:///android_asset/default.html"); } final class EHJavaScriptInterface { EHJavaScriptInterface() { } public void loadLayout(final String lo) { int i = Integer.parseInt(lo.trim()); switch (i) { /****** THIS IS WHERE I'M BOMBING OUT *********/ case FEATURED: setContentView(R.layout.featured);break; case MAIN: setContentView(R.layout.main);break; } } }

    Read the article

  • Passing an arbitrary JSONValue to a JSNI function

    - by Riley Lark
    I have a JSONValue in my Java that may be a JSONArray, a JSONObject, a JSONString, etc. I want to pass it to a JSNI function that can accept any of those types. If I naively write my JSNI as something like: public final native jsni(Object parameter) /*-{ doSomething(parameter); }-*/; public void useFunction(JSONValue value) { jsni(value); //Throws js exception at runtime :( } then I get a javascript exception, because GWT doesn't know how to convert the JSONValue to a JavaScriptObject (or native string / number value). My current workaround is public final native jsniForJSO(Object parameter) /*-{ doSomething(parameter); }-*/; public final native jsniForString(String parameter) /*-{ doSomething(parameter); }-*/; public final native jsniForNumber(double parameter) /*-{ doSomething(parameter); }-*/; public actuallyUseFunction(JSONValue value) { if (value.isObject()) { jsniForJSO(value.isObject().getJavaScriptObject()); } else if (value.isString()) { jsniForString(value.isString().stringValue()); } else { //etc } } This is a big burden for code maintainability, etc... especially if you have more than one parameter. Is there a way to generate these functions automatically, or get around this issue altogether? I've taken to wrapping everything in a JSONObject first, so I can definitely get a JavaScriptObject to pass to my jsni, but that's another clumsy mechanic.

    Read the article

  • java - powermock whenNew doesnt seem to work, calls the actual constructor

    - by user1331243
    I have two final classes that are used in my unit test. I am trying to use whenNew on the constructor of a final class, but I see that it calls the actual constructor. The code is @PrepareForTest({A.class, B.class, Provider.class}) @Test public void testGetStatus() throws Exception { B b = mock(B.class); when(b.getStatus()).thenReturn(1); whenNew(B.class).withArguments(anyString()).thenReturn(b); Provider p = new Provider(); int val = p.getStatus(); assertTrue((val == 1)); } public class Provider { public int getStatus() { B b = new B("test"); return b.getStatus(); } } public final class A { private void init() { // ...do soemthing } private static A a; private A() { } public static A getInstance() { if (a == null) { a = new A(); a.init(); } return a; } } public final class B { public B() { } public B(String s) { this(A.getInstance(), s); } public B(A a, String s) { } public int getStatus() { return 0; } } On debug, I find that its the actual class B instance created and not the mock instance that is returned for new usage and assertion fails. Any pointers on how to get this working. Thanks

    Read the article

  • Simple encryption - Sum of Hashes in C

    - by Dogbert
    I am attempting to demonstrate a simple proof of concept with respect to a vulnerability in a piece of code in a game written in C. Let's say that we want to validate a character login. The login is handled by the user choosing n items, (let's just assume n=5 for now) from a graphical menu. The items are all medieval themed: eg: _______________________________ | | | | | Bow | Sword | Staff | |-----------|-----------|-------| | Shield | Potion | Gold | |___________|___________|_______| The user must click on each item, then choose a number for each item. The validation algorithm then does the following: Determines which items were selected Drops each string to lowercase (ie: Bow becomes bow, etc) Calculates a simple string hash for each string (ie: `bow = b=2, o=15, w=23, sum = (2+15+23=40) Multiplies the hash by the value the user selected for the corresponding item; This new value is called the key Sums together the keys for each of the selected items; this is the final validation hash IMPORTANT: The validator will accept this hash, along with non-zero multiples of it (ie: if the final hash equals 1111, then 2222, 3333, 8888, etc are also valid). So, for example, let's say I select: Bow (1) Sword (2) Staff (10) Shield (1) Potion (6) The algorithm drops each of these strings to lowercase, calculates their string hashes, multiplies that hash by the number selected for each string, then sums these keys together. eg: Final_Validation_Hash = 1*HASH(Bow) + 2*HASH(Sword) + 10*HASH(Staff) + 1*HASH(Shield) + 6*HASH(Potion) By application of Euler's Method, I plan to demonstrate that these hashes are not unique, and want to devise a simple application to prove it. in my case, for 5 items, I would essentially be trying to calculate: (B)(y) = (A_1)(x_1) + (A_2)(x_2) + (A_3)(x_3) + (A_4)(x_4) + (A_5)(x_5) Where: B is arbitrary A_j are the selected coefficients/values for each string/category x_j are the hash values for each string/category y is the final validation hash (eg: 1111 above) B,y,A_j,x_j are all discrete-valued, positive, and non-zero (ie: natural numbers) Can someone either assist me in solving this problem or point me to a similar example (ie: code, worked out equations, etc)? I just need to solve the final step (ie: (B)(Y) = ...). Thank you all in advance.

    Read the article

  • JSF, writeAttribute("value", str, null) fails with strings obtained through ValueExpression.getValue

    - by Roma
    Hello, I'm having a somewhat weird problem with custom JSF component. Here's my renderer code: public class Test extends Renderer { public void encodeBegin(final FacesContext context, final UIComponent component) throws IOException { ResponseWriter writer = context.getResponseWriter(); writer.startElement("textarea", component); String clientId = component.getClientId(context); if (clientId != null) writer.writeAttribute("name", clientId, null); ValueExpression exp = component.getValueExpression("value"); if (exp != null && exp.getValue(context.getELContext()) != null) { String val = (String) exp.getValue(context.getELContext()); System.out.println("Value: " + val); writer.writeAttribute("value", val, null); } writer.endElement("textarea"); writer.flush(); } } The code generates: <textarea name="j_id2:j_id12:j_id19" value=""></textarea> Property binding contains "test" and as it should be, "Value: test" is successfully printed to console. Now, if I change the code to: public void encodeBegin(final FacesContext context, final UIComponent component) throws IOException { ResponseWriter writer = context.getResponseWriter(); writer.startElement("textarea", component); String clientId = component.getClientId(context); if (clientId != null) writer.writeAttribute("name", clientId, null); ValueExpression exp = component.getValueExpression("value"); if (exp != null && exp.getValue(context.getELContext()) != null) { String val = (String) exp.getValue(context.getELContext()); String str = "new string"; System.out.println("Value1: " + val + ", Value2: " + str); writer.writeAttribute("value", str, null); } writer.endElement("textarea"); writer.flush(); } generated html is: <textarea name="j_id2:j_id12:j_id19" value="new string"></textarea> and console output is "Value1: test, Value2: new string" What's going on here? This doesn't make sense. Why would writeAttribute differentiate between the two strings? Additional info: The component extends UIComponentBase I am using it with facelets

    Read the article

  • Calling web service from seems to hang

    - by anothershrubery
    I am trying to call an asmx web service from an Android app. Just literally started some Android development today. I've been following various solutions I have found on the net and on here and it seems it is more difficult than anticipated. I have tried various solutions and using KSoap2 seems to be the easiest way to implement this, well it would be if I could get it working. I have the following code which works up until a point: private class CallWebService extends AsyncTask<Void, Void, Void> { private static final String SOAP_ACTION = "http://tempuri.org/GetUser"; private static final String METHOD_NAME = "GetUser"; private static final String NAMESPACE = "http://tempuri.org/"; private static final String URL = "http://160.10.1.79:59315/Service1.asmx"; TextView tv; @Override protected Void doInBackground(Void... params) { tv=(TextView)findViewById(R.id.txtMessage); try { SoapObject request = new SoapObject(NAMESPACE, METHOD_NAME); SoapSerializationEnvelope envelope = new SoapSerializationEnvelope(SoapEnvelope.VER11); envelope.dotNet=true; envelope.setOutputSoapObject(request); HttpTransportSE androidHttpTransport = new HttpTransportSE(URL); androidHttpTransport.call(SOAP_ACTION, envelope); Object result = (Object)envelope.getResponse(); tv.setText(result.toString()); } catch (Exception e) { tv.setText(e.getMessage()); } return null; } } It seems to hang at the line androidHttpTransport.call(SOAP_ACTION, envelope); Any ideas why? Is this the correct approach? Should I be looking in another direction?

    Read the article

  • JPA entitylisteners and @embeddable

    - by seanizer
    I have a class hierarchy of JPA entities that all inherit from a BaseEntity class: @MappedSuperclass @EntityListeners( { ValidatorListener.class }) public abstract class BaseEntity implements Serializable { // other stuff } I want all entities that implement a given interface to be validated automatically on persist and/or update. Here's what I've got. My ValidatorListener: public class ValidatorListener { private enum Type { PERSIST, UPDATE } @PrePersist public void checkPersist(final Object entity) { if (entity instanceof Validateable) { this.check((Validateable) entity, Type.PERSIST); } } @PreUpdate public void checkUpdate(final Object entity) { if (entity instanceof Validateable) { this.check((Validateable) entity, Type.UPDATE); } } private void check(final Validateable entity, final Type persist) { switch (persist) { case PERSIST: if (entity instanceof Persist) { ((Persist) entity).persist(); } if (entity instanceof PersistOrUpdate) { ((PersistOrUpdate) entity).persistOrUpdate(); } break; case UPDATE: if (entity instanceof Update) { ((Update) entity).update(); } if (entity instanceof PersistOrUpdate) { ((PersistOrUpdate) entity).persistOrUpdate(); } break; default: break; } } } and here's my Validateable interface that it checks against (the outer interface is just a marker, the inner contain the methods): public interface Validateable { interface Persist extends Validateable { void persist(); } interface PersistOrUpdate extends Validateable { void persistOrUpdate(); } interface Update extends Validateable { void update(); } } All of this works, however I would like to extend this behavior to Embeddable classes. I know two solutions: call the validation method of the embeddable object manually from the entity validation method: public void persistOrUpdate(){ // validate my own properties first // then manually validate the embeddable property: myEmbeddable.persistOrUpdate(); // this works but I'd like something that I don't have to call manually } use reflection, checking all properties to see if their type is of one of their interface types. This would work, but it's not pretty. Is there a more elegant solution?

    Read the article

  • Why am I getting a ClassCastException here?

    - by Holly
    I'm creating an android application and i'm trying to use a PreferenceActivity. I'm getting the java.lang.ClassCastException: java.lang.String error when it gets to this line return PreferenceManager.getDefaultSharedPreferences(context).getInt(USER_TERM, USER_TERM_DEF); I thought it might be because I'm not converting it properly from it's string value in the EditText box to the int I need but I can't figure out how to fix this, or is that even the cause? I'm flummoxed. Here's my preference activity class: public class UserPrefs extends PreferenceActivity { //option names and default vals private static final String USER_TERM = "term_length"; private static final String USER_YEAR = "year_length"; private static final int USER_TERM_DEF = 12; private static final int USER_YEAR_DEF = 34; @Override protected void onCreate(Bundle savedInstanceState){ super.onCreate(savedInstanceState); addPreferencesFromResource(R.xml.preferences); } public static int getTermLength(Context context){ try{ return PreferenceManager.getDefaultSharedPreferences(context).getInt(USER_TERM, USER_TERM_DEF); }catch (ClassCastException e){Log.v("getTermLength", "error::: " + e); } //return 1;//temporary, needed to catch the error and couldn't without adding a return outside the block.// } public static int getYearLength(Context context){ return PreferenceManager.getDefaultSharedPreferences(context).getInt(USER_YEAR, USER_YEAR_DEF); } And here's the bit of code where I'm trying to use the the preferences inside another class: public float alterForFrequency(Context keypadContext, float enteredAmount, String spinnerPosition){ int termLength = UserPrefs.getTermLength(keypadContext); int yearLength = UserPrefs.getYearLength(keypadContext); } The complete android logcat, i've uploaded here: http://freetexthost.com/v3t4ta3wbi

    Read the article

  • Sending data back to Controller Spring-MVC

    - by Umesh Awasthi
    I am not sure if this is a complex problem but as a starting person this seems a bit complex to me. I have an object based on which i need to show some values on the UI and let user select some of them, i need to send data back to another controller when user click on the submit button.Here is the structure of my data object public class PrsData{ private Map<String, List<PrsCDData>> prsCDData; } public class PrsCDData{ private Map<String, Collection<ConfiguredDesignData>> configuredDesignData; } public ConfiguredDesignData{ // simple fields } I have set the object in model before showing the view like model.addAttribute("prsData", productData.getPrData()); In the form i have following settings <form:form method="post" commandName="prsData" action="${addProductToCartAction}" > <form:hidden path="prsCDData['${prsCDDataMap.key}'] [${status.index}].configuredDesignData['${configuredDesignDataMap.key}'] [${configuredDesignDataStatus.index}].code"/> <form:hidden path="prsCDData['${prsCDDataMap.key}'] [${status.index}].configuredDesignData['${configuredDesignDataMap.key}'] [${configuredDesignDataStatus.index}].description"/> </form:form> This is what i have at AddProductToCartController public String addToCart(@RequestParam("productCodePost") final String code, @ModelAttribute("prsData") final PrsData prsData, final Model model, @RequestParam(value = "qty", required = false, defaultValue = "1") final long qty) On submitting the form i am getting following exception org.springframework.beans.NullValueInNestedPathException: Invalid property 'prsCDData[Forced][0]' of bean class [com.product.data.PrsData]: Cannot access indexed value of property referenced in indexed property path 'prsCDData[Forced][0]': returned null It seems like its trying to access the values on this controller while i am trying to send value to that controller and trying to create same object with selected values Can any one tell me where i am doing wrong and what i need to take care of

    Read the article

  • how to show all added items into another activity, like: AddtoCart and ViewCart Functionality

    - by Stanley
    i am trying to make a shopping cart app, allowing user to choose category then select item to purchase, once user will click on any item to purchase, then showing that selected item into another activity with item image, name, cost, qty (to accept by user) and also providing add to cart functionality, now i want whenever user will click on Add to Cart button, then selected item need to show in ViewCart Activity, so here i am placing my AddtoCart Activity code, please tell me what i need to write to show added item(s) into ViewCart Category just like in shopping cart, In ViewCart activity i just want to show item title, cost and qty (entered by user):- public class AddtoCart extends Activity{ static final String KEY_TITLE = "title"; static final String KEY_COST = "cost"; static final String KEY_THUMB_URL = "imageUri"; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.single); Intent in = getIntent(); String title = in.getStringExtra(KEY_TITLE); String thumb_url = in.getStringExtra(KEY_THUMB_URL); String cost = in.getStringExtra(KEY_COST); ImageLoader imageLoader = new ImageLoader(getApplicationContext()); ImageView imgv = (ImageView) findViewById(R.id.single_thumb); TextView txttitle = (TextView) findViewById(R.id.single_title); TextView txtcost = (TextView) findViewById(R.id.single_cost); txttitle.setText(title); txtcost.setText(cost); imageLoader.DisplayImage(thumb_url, imgv); // Save a reference to the quantity edit text final EditText editTextQuantity = (EditText) findViewById(R.id.edit_qty); ImageButton addToCartButton = (ImageButton) findViewById(R.id.img_add); addToCartButton.setOnClickListener(new OnClickListener() { public void onClick(View v) { // Check to see that a valid quantity was entered int quantity = 0; try { quantity = Integer.parseInt(editTextQuantity.getText() .toString()); if (quantity <= 0) { Toast.makeText(getBaseContext(), "Please enter a quantity of 1 or higher", Toast.LENGTH_SHORT).show(); return; } } catch (Exception e) { Toast.makeText(getBaseContext(), "Please enter a numeric quantity", Toast.LENGTH_SHORT).show(); return; } // Close the activity finish(); } }); }}

    Read the article

  • Interview Q: sorting an almost sorted array (elements misplaced by no more than k)

    - by polygenelubricants
    I was asked this interview question recently: You're given an array that is almost sorted, in that each of the N elements may be misplaced by no more than k positions from the correct sorted order. Find a space-and-time efficient algorithm to sort the array. I have an O(N log k) solution as follows. Let's denote arr[0..n) to mean the elements of the array from index 0 (inclusive) to N (exclusive). Sort arr[0..2k) Now we know that arr[0..k) are in their final sorted positions... ...but arr[k..2k) may still be misplaced by k! Sort arr[k..3k) Now we know that arr[k..2k) are in their final sorted positions... ...but arr[2k..3k) may still be misplaced by k Sort arr[2k..4k) .... Until you sort arr[ik..N), then you're done! This final step may be cheaper than the other steps when you have less than 2k elements left In each step, you sort at most 2k elements in O(k log k), putting at least k elements in their final sorted positions at the end of each step. There are O(N/k) steps, so the overall complexity is O(N log k). My questions are: Is O(N log k) optimal? Can this be improved upon? Can you do this without (partially) re-sorting the same elements?

    Read the article

  • showDialog in Activity not displaying dialog

    - by Mohit Deshpande
    Here is my code: public class TasksList extends ListActivity { ... private static final int COLUMNS_DIALOG = 7; private static final int ORDER_DIALOG = 8; ... /** * @see android.app.Activity#onCreateDialog(int) */ @Override protected Dialog onCreateDialog(int id) { Dialog dialog; final String[] columns; Cursor c = managedQuery(Tasks.CONTENT_URI, null, null, null, null); columns = c.getColumnNames(); final String[] order = { "Ascending", "Descending" }; switch (id) { case COLUMNS_DIALOG: AlertDialog.Builder columnDialog = new AlertDialog.Builder(this); columnDialog.setSingleChoiceItems(columns, -1, new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { bundle.putString("column", columns[which]); } }); dialog = columnDialog.create(); case ORDER_DIALOG: AlertDialog.Builder orderDialog = new AlertDialog.Builder(this); orderDialog.setSingleChoiceItems(order, -1, new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { String orderS; if (order[which].equalsIgnoreCase("Ascending")) orderS = "ASC"; else orderS = "DESC"; bundle.putString("order", orderS); } }); dialog = orderDialog.create(); default: dialog = null; } return dialog; } /** * @see android.app.Activity#onOptionsItemSelected(android.view.MenuItem) */ @Override public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId()) { case SORT_MENU: showDialog(COLUMNS_DIALOG); showDialog(ORDER_DIALOG); String orderBy = bundle.getString("column") + bundle.getString("order"); Cursor tasks = managedQuery(Tasks.CONTENT_URI, projection, null, null, orderBy); adapter = new TasksAdapter(this, tasks); getListView().setAdapter(adapter); break; case FILTER_MENU: break; } return false; } The showDialog doesn't display the dialog. I used the Debugger and it does executes these statements, but the dialog doesn't show. }

    Read the article

  • Generic factory of generic containers

    - by Feuermurmel
    I have a generic abstract class Factory<T> with a method createBoxedInstance() which returns instances of T created by implementations of createInstance() wrapped in the generic container Box<T>. abstract class Factory<T> { abstract T createInstance(); public final Box<T> createBoxedInstance() { return new Box<T>(createInstance()); } public final class Box<T> { public final T content; public Box(T content) { this.content = content; } } } At some points I need a container of type Box<S> where S is an ancestor of T. Is it possible to make createBoxedInstance() itself generic so that it will return instances of Box<S> where S is chosen by the caller? Sadly, defining the function as follows does not work as a type parameter cannot be declared using the super keyword, only used. public final <S super T> Box<S> createBoxedInstance() { return new Box<S>(createInstance()); } The only alternative I see, is to make all places that need an instance of Box<S> accept Box<? extends S> which makes the container's content member assignable to S. Is there some way around this without re-boxing the instances of T into containers of type Box<S>? (I know I could just cast the Box<T> to a Box<S> but I would feel very, very guilty.)

    Read the article

  • Twitter ?? Nashorn ????(??)

    - by Homma
    ???? Nashorn ? Java ??????? Twitter ???????????????????? JavaFX ??????????????? ????? ??? jlaskey ??? Nashorn Blog ????????????? https://blogs.oracle.com/nashorn/entry/nashorn_in_the_twitterverse_continued ???????? ?? Twitter ???????????????????????? JavaFX ??????????????????????????????? Nashorn ?? JavaFX ??????????????JavaFX ???????????????????????????????????????Nashorn ? Java ????????????????????????????????????(JavaFX ?????????????????????)? ?????????????????????????????????????????????? Twitter ????????????????????????? var twitter4j = Packages.twitter4j; var TwitterFactory = twitter4j.TwitterFactory; var Query = twitter4j.Query; function getTrendingData() { var twitter = new TwitterFactory().instance; var query = new Query("nashorn OR nashornjs"); query.since("2012-11-21"); query.count = 100; var data = {}; do { var result = twitter.search(query); var tweets = result.tweets; for each (var tweet in tweets) { var date = tweet.createdAt; var key = (1900 + date.year) + "/" + (1 + date.month) + "/" + date.date; data[key] = (data[key] || 0) + 1; } } while (query = result.nextQuery()); return data; } ??????????????????getTrendingData() ??????????????(??????????Nashorn ???????? OpenJDK ?????? 2012 ? 11 ? 21 ???)??????????????????????????????????? ????JavaFX ? BarChart ??????????? var javafx = Packages.javafx; var Stage = javafx.stage.Stage var Scene = javafx.scene.Scene; var Group = javafx.scene.Group; var Chart = javafx.scene.chart.Chart; var FXCollections = javafx.collections.FXCollections; var ObservableList = javafx.collections.ObservableList; var CategoryAxis = javafx.scene.chart.CategoryAxis; var NumberAxis = javafx.scene.chart.NumberAxis; var BarChart = javafx.scene.chart.BarChart; var XYChart = javafx.scene.chart.XYChart; var Series = javafx.scene.chart.XYChart.Series; var Data = javafx.scene.chart.XYChart.Data; function graph(stage, data) { var root = new Group(); stage.scene = new Scene(root); var dates = Object.keys(data); var xAxis = new CategoryAxis(); xAxis.categories = FXCollections.observableArrayList(dates); var yAxis = new NumberAxis("Tweets", 0.0, 200.0, 50.0); var series = FXCollections.observableArrayList(); for (var date in data) { series.add(new Data(date, data[date])); } var tweets = new Series("Tweets", series); var barChartData = FXCollections.observableArrayList(tweets); var chart = new BarChart(xAxis, yAxis, barChartData, 25.0); root.children.add(chart); } ????????????????????????????????stage.scene = new Scene(root) ? stage.setScene(new Scene(root)) ????????????????????Nashorn ? stage ??????? scene ???????????????????(Dynalink ?????????)Java Beans ???????????????? (setScene()) ???????????????????????????????Nashorn ? FXCollections ??????????????????????????????observableArrayList(dates) ??????????Nashorn ? JavaScript ??? (dates) ? Java ???????????????????????????? JavaScript ?????????????????? Java ????????????????????????????????????????????????????????????? ????????????????????????????????? JavaFX ???????????????????????? JavaFX ??????????????javafx.application.Application ??????????????????????????? JavaFX ????????????????????????????????????????????????? import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import javafx.application.Application; import javafx.stage.Stage; import javax.script.ScriptEngine; import javax.script.ScriptEngineManager; import javax.script.ScriptException; public class TrendingMain extends Application { private static final ScriptEngineManager MANAGER = new ScriptEngineManager(); private final ScriptEngine engine = MANAGER.getEngineByName("nashorn"); private Trending trending; public static void main(String[] args) { launch(args); } @Override public void start(Stage stage) throws Exception { trending = (Trending) load("Trending.js"); trending.start(stage); } @Override public void stop() throws Exception { trending.stop(); } private Object load(String script) throws IOException, ScriptException { try (final InputStream is = TrendingMain.class.getResourceAsStream(script)) { return engine.eval(new InputStreamReader(is, "utf-8")); } } } ???? Nashorn ??????? JSR-223 ? javax.script ????????? private static final ScriptEngineManager MANAGER = new ScriptEngineManager(); private final ScriptEngine engine = MANAGER.getEngineByName("nashorn"); ????????? JavaScript ???????? Nashorn ???????????????????? load ???????????????????????engine ???????????????load ????????????? ???????????????Java ???????????????????????????????????????????????????? Java ????????????????JavaFX ???????? start ????? stop ?????????????????????????????????????? public interface Trending { public void start(Stage stage) throws Exception; public void stop() throws Exception; } ?????????????????????????????? function newTrending() { return new Packages.Trending() { start: function(stage) { var data = getTrendingData(); graph(stage, data); stage.show(); }, stop: function() { } } } newTrending(); ?????? Trending ?????????????????????start ????? stop ??????????????????????????????????? eval ???? Java ??????????????? trending = (Trending) load("Trending.js"); ????????????????Trending.js ??????? getTrendingData ???????????? newTrending ????????????????????? Java ?????????newTrending ????????? eval ????????? Trending ????????????????????????????????????????????????????????? trending.start(stage); ???????? ???? Nashorn ????????? http://www.myexpospace.com/JavaOne2012/SessionFiles/CON5251_PDF_5251_0001.pdf ???????? Dynalink ??????? https://github.com/szegedi/dynalink ????????

    Read the article

< Previous Page | 20 21 22 23 24 25 26 27 28 29 30 31  | Next Page >