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Search found 533 results on 22 pages for 'nullpointerexception'.

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  • Java init method

    - by Johan Sjöberg
    What's a good way to make sure an init method is invoked in java? The alternatives I see are Don't test it, let the method fail by itself, likely by a NullPointerException Test if method was initialized or throw public void foo() { if (!inited) { throw new IllegalArgumentException("not initalized"); } ... } Delagate public void foo() { if (!inited) { throw new IllegalArgumentException("not initalized"); } fooInternal(); } private void fooInternal(){ ... }; Always init, and make init a noop otherwise public void foo() { init(); ... } public void init() { if(!inited) { ... } } Silently init public void foo() { if (!inited) { init(); } ... } Most of these approaches are very verbose and decreases overall readability.

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  • Java: JSP halt execution on rest of page

    - by bguiz
    Hi, How do you stop a JSP from executing? I have JSPs which kick the user off a page by means of a "forward". public boolean kickIfNotLoggedIn( HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException { //code to check if user is logged in req.getRequestDispatcher( ACCESS_DENIED_PAGE).forward(request, response); } In my JSP, I have this code, BEFORE any HTML output: <% //loginHelper.kickIfNotLoggedIn(request, response); if (!loginHelper.kickIfNotLoggedIn(request, response)) { return; } %> If I don't use the return statement, the JSP continues processing, and I get a NullPointerException. If I use the return statement (as is commonly suggested on various sources on the net), I get an IllegalStateException: StandardWrapperValve[jsp]: PWC1406: Servlet.service() for servlet jsp threw exception java.lang.IllegalStateException: PWC3991: getOutputStream() has already been called for this response at org.apache.coyote.tomcat5.CoyoteResponse.getWriter(CoyoteResponse.java:717) at org.apache.coyote.tomcat5.CoyoteResponseFacade.getWriter(CoyoteResponseFacade.java:226) at org.apache.jasper.runtime.JspWriterImpl.initOut(JspWriterImpl.java:187) Any ideas how to fix this, or another way to achieve an access denied page? Thanks

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  • migrate database from sybase to mysql

    - by jindalsyogesh
    I have been trying to migrate a database from sybase to Mysql. This is my approach: Generate pojo classes from my sybase database using hibernate in eclipse Use these pojo classes to generate the schema in mysql database Then somehow migrate the data from sybase to mysql I guess this approach should work??? Please let me know if there is any better or easier approach. The thing is I am not even able to get the first step done. I added hibernate plugin in eclipse from this link: [http://download.jboss.org/jbosstools/updates/stable/][1] I added sybase jar file to my project classpath Then I added hibernate console configuration file Then I added hibernate configuration file Then I added hibernate code generation configuration When I try to run the code generation configuration file, I am getting java.lang.NullPointerException and I have no idea how to fix it. I searched a lot of forums, tried to google it, but I not able to find any solution. Can anybody tell me what mistake I am making here or point to some hibernate tutorial for eclipse??

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  • New/strange Java "try()" syntax?

    - by Ali
    While messing around with the custom formatting options in Eclipse, in one of the sample pieces of code, I say code as follows: /** * 'try-with-resources' */ class Example { void foo() { try (FileReader reader1 = new FileReader("file1"); FileReader reader2 = new FileReader("file2")) { } } } I've never seen try used like this and I've been coding in Java for 9 years! Does any one know why you would do this? What is a possible use-case / benefit of doing this? An other pieces of code I saw, I thought was a very useful shorthand so I'm sharing it here as well, it's pretty obvious what it does: /** * 'multi-catch' */ class Example { void foo() { try { } catch (IllegalArgumentException | NullPointerException | ClassCastException e) { e.printStackTrace(); } } }

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  • Console class in java Exception in reading password

    - by satheesh
    Hi, i am trying to use Console class in java. with this code import java.io.Console; public class ConsoleClass { public static void main(String[] args){ Console c=System.console(); char[] pw; pw=c.readPassword("%s","pw :"); for(char ch:pw){ c.format("%c",ch); } c.format("\n"); MyUtility mu =new MyUtility(); while(true){ String name=c.readLine("%s", "input?: "); c.format("output: %s \n",mu.doStuff(name)); } } } class MyUtility{ String doStuff(String arg1){ return "result is " +arg1; } } here i am getting NullPointerException when i tried to run in netbeans but i am not getting any Exception when tried to run in cmd with out netbeans IDE.Why?

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  • What are the possible causes of JasperException

    - by CitadelCSCadet
    I have a JSP that takes an Arraylist from the session object and removes the items from it. It seemed to be working fine and then out of nowhere when I navigate to that page, the page is blank. I checked the Tomcat log files and in catalina.out I am receiving a JasperException an it is showing it as being on a line with the following for(int i; i < agentItems.size(); i++) agentItems is the name of the ArrayList I am using. I have been debugging it and can't seem to figure out what the problem might be. I have read that a JasperException is sometiems thrown as a JSP's NullPointerException. Is this true or am I just completely overlooking the problem? I have the web application running on a local machine and a intermediate server for development in which both of them have had no trouble. Why could it be that only on this server it is giving me problems?

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  • Why Eclipse does not see .jar file of a library?

    - by Roman
    I have a java project in which I have "Referenced Libraries". In the "Referenced Libraries" I have a .jar file of a library that I use (I use only one external library). When I try to "Run - Run" the code I have a NullPointerException. From my previous experience I know that it it (very likely) because my code does not see the library. I just started to use Eclipse and it can be the I do not "connect" libraries in a correct way. Should I use some options or additional action to force Eclipse to see the .jar file of the library? ADDED: By the right click on the library I get a drop-down menu in which I see "Build Path". My be I need to do something there?

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  • Android's listview. Update view within of of the cells just after invalidating Activity's view

    - by davs
    I have ListViewActivity public class SelectActivity extends ListActivity { protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.select_one_of); SimpleAdapter adapter = new SimpleAdapter( this, createChildList(), R.layout.select_one_of_childrow, new String[] { KEY_VALUE }, new int[] { R.id.selectoneof_add_new_item}); setListAdapter(adapter); } // ... } after setListAdapter() calls I would like to execute the following code: ((TextView) getListView().getChildAt(0).findViewById(R.id.selectoneof_add_new_item)).setCompoundDrawablesWithIntrinsicBounds(0, 0, R.drawable.ticked, 0); but getListView().getChildAt(xxx) returns null and I catch NullPointerException. Where should I put mentioned above code-snippet?

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  • JPA EclipseLink Auditing for Oracle issue with SessionCustomizer...

    - by enrique
    I was trying to use the SessionCustomizer for auditing with v$session.program for oracle and it works with JDBC but i need it working with JPA, so i read a bit more the documentation for SESSION_CUSTOMIZER in this site: http://wiki.eclipse.org/Using_EclipseLink_JPA_Extensions_(ELUG)#EclipseLink_JPA_Persistence_Unit_Properties_for_Customization_and_Validation but had not lucky in making it work in passing the program name parameter to oracle with the v$session.program... i was using the SessionCustomizer and it is an interface so my code is as follows: package com.util; import org.eclipse.persistence.config.SessionCustomizer; import org.eclipse.persistence.sessions.Session; /** * * @author xkalibur */ public class ProgramCustomizer implements SessionCustomizer{ public void customize(Session s) throws Exception { s.getDatasourceLogin().setProperty("v$session.program","Customers"); } } then in CustomerFacade : ProgramCustomizer pc=new ProgramCustomizer(); public void edit(Customer customer) { emProperties.put(PersistenceUnitProperties.SESSION_CUSTOMIZER,pc); em=factory.createEntityManager(emProperties); em.merge(customer); } and returns the following error: javax.ejb.EJBException Caused by: java.lang.NullPointerException at com.facades.CustomerFacade.edit(CustomerFacade.java:48) please some help...

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  • How to use JAXB APIs to generate classes from xsd?

    - by Simran
    I need to generate bean classes from .xsd without using xjc command or ant. i have found the implementation in Apache Axis2 but i am unable to generate the artifacts. i have written the following code but i get NullPointerException : SchemaCompiler sc = XJC.createSchemaCompiler(); URL url = new URL("file://E:\\JAXB\\books.xsd"); sc.parseSchema(new InputSource(url.toExternalForm())); S2JJAXBModel model = sc.bind(); JCodeModel cm = model.generateCode(null, null); cm.build(new FileCodeWriter(new File("E:\\JAXBTest"))); Can anyone help me / provide some links???

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  • Understanding Clojure concurrency example

    - by dusha
    Hello, I just go through various documentation on Clojure concurrency and came accross the example on the website (http://clojure.org/concurrent_programming). (import '(java.util.concurrent Executors)) (defn test-stm [nitems nthreads niters] (let [refs (map ref (replicate nitems 0)) pool (Executors/newFixedThreadPool nthreads) tasks (map (fn [t] (fn [] (dotimes [n niters] (dosync (doseq [r refs] (alter r + 1 t)))))) (range nthreads))] (doseq [future (.invokeAll pool tasks)] (.get future)) (.shutdown pool) (map deref refs))) I understand what it does and how it works, but I don't get why the second anonymous function fn[] is needed? Many thanks, dusha. P.S. Without this second fn [] I get NullPointerException.

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  • What's causing "Unable to retrieve native address from ByteBuffer object"?

    - by r0u1i
    As a very novice Java programmer, I probably should not mess with that kind of things. Unfortunately, I'm using a library which have a method that accepts a ByteBuffer object and throws when I try to use it: Exception in thread "main" java.lang.NullPointerException: Unable to retrieve native address from ByteBuffer object Is it because I'm not using a non-direct buffer? edit: There's not a lot of my code there. The library I'm using is jNetPcap, and I'm trying to dump a packet to file. My code takes an existing packet, and extract a ByteBuffer out of it: byte[] bytes = m_packet.getByteArray(0, m_packet.size()); ByteBuffer buffer = ByteBuffer.wrap(bytes); Then it calls on of the dump methods of jNetPcap that takes a ByteBuffer.

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  • Confused by "let" in Clojure

    - by Tom Dalling
    I just started playing with Clojure, and I wrote a small script to help me understand some of the functions. It begins like this: (def *exprs-to-test* [ "(filter #(< % 3) '(1 2 3 4 3 2 1))" "(remove #(< % 3) '(1 2 3 4 3 2 1))" "(distinct '(1 2 3 4 3 2 1))" ]) Then it goes through *exprs-to-test*, evaluates them all, and prints the output like this: (doseq [exstr *exprs-to-test*] (do (println "===" (first (read-string exstr)) "=========================") (println "Code: " exstr) (println "Eval: " (eval (read-string exstr))) ) ) The above code is all working fine. However, (read-string exstr) is repeated so I tried to use let to eliminate the repetition like so: (doseq [exstr *exprs-to-test*] (let [ex (read-string exstr)] ( (do (println "===" (first ex) "=========================") (println "Code: " exstr) (println "Eval: " (eval ex)) ) )) ) But this works once for the first item in *exprs-to-test*, then crashes with a NullPointerException. Why is the addition of let causing the crash?

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  • Cannot get principal id on my Spock test

    - by Ant's
    I have a controller like this : @Secured(['ROLE_USER','IS_AUTHENTICATED_FULLY']) def userprofile(){ def user = User.get(springSecurityService.principal.id) params.id = user.id redirect (action : "show", params:params) } I want to test the controller above controller in spock, so I wrote a test code like this: def 'userProfile test'() { setup: mockDomain(User,[new User(username:"amtoasd",password:"blahblah")]) when: controller.userprofile() then: response.redirectUrl == "/user/show/1" } When I run my test, this test fails with this error message : java.lang.NullPointerException: Cannot get property 'principal' on null object at mnm.schedule.UserController.userprofile(UserController.groovy:33) And in case of Integration test: class UserSpec extends IntegrationSpec { def springSecurityService def 'userProfile test'() { setup: def userInstance = new User(username:"antoaravinth",password:"secrets").save() def userInstance2 = new User(username:"antoaravinthas",password:"secrets").save() def usercontroller = new UserController() usercontroller.springSecurityService = springSecurityService when: usercontroller.userprofile() then: response.redirectUrl == "/user/sho" } } I get the same error as well. What went wrong? Thanks in advance.

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  • Print an EObject ?

    - by tul
    I am writing some eclipse emf code and would like to print the content of an EObject (not store it to disk). Here is what I try: public static void print(EObject obj) { Resource eResource = obj.eResource(); try { eResource.save(System.out, null); } catch (IOException e) { e.printStackTrace(); } } but that gives a NullPointerException. I have tried this instead: public static void print(EObject obj) { ResourceSet resourceSet = new ResourceSetImpl(); resourceSet.getResourceFactoryRegistry().getProtocolToFactoryMap() .put("*", new XMIResourceFactoryImpl()); Resource resource = resourceSet.createResource(URI.createURI("dummyfile.xml")); resource.getContents().add(obj); try { resource.save(System.out, null); } catch (IOException ioe) { ioe.printStackTrace(); } } This works, but is it not possible to print to screen without specifying a dummy URI??

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  • How to set a custom font for a spinner?

    - by AndrewC
    Is there anyway to set a custom font or color for the selected item in a Spinner? For example, I open the spinner and click a priority of "High". I'm my layout containing the spinner, I would like to see the word "High" in red or a custom font. I can't seem to obtain the textview to make the necessary change. I always obtain a NullPointerException if I typecast the spinner.getSelectedView() to textview and attempt to set the color. any ideas? thanks in advance!

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  • partition from programming pearls

    - by davit-datuashvili
    hi suppose i have following array int a[]=new int[]{55,41,59,26,53,58,97,93}; i want to partition it around 55 so new array will be such } 41,26,53,55,59,58,93,93}; i have done such kinds of problems myself but this is from programming pearls and here code is like this we have some array[a..b] and given value t we write code following way int m=a-1; for i=[a..b] if ( array[i]<t) swap (++m;i); where swap function exchange two element in array at indexes ++m and i, i have run this program and it showed me mistake Exception java.lang.NullPointerException can anybody help me?

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  • How select data from SQLite table where date = week of year?

    - by vovaxo
    I have table expense: "create table " + Expense.TABLE_NAME + "(" + Expense.ID + " integer primary key autoincrement not null, " + Expense.CATEGORY_ID + " integer, " + Expense.ITEM + " text, " + Expense.PRICE + " real, " + Expense.DATE + " date, " + Expense.TIME + " time);"; And I want to select Expense.PRICE where Expense.DATE = current day/week/month. I tried to do this cursor = mDB.rawQuery("select " + Expense.PRICE + " where " + " (strftime('%W', " + Expense.DATE + "))" + "=" + week, null); where week is week = calendar.get(Calendar.WEEK_OF_YEAR); but it gives an error in cursor: 09-15 09:32:02.647: E/AndroidRuntime(18939): Caused by: java.lang.NullPointerException 09-15 09:32:02.647: E/AndroidRuntime(18939): at com.pllug.summercamp.expensemanager.DataAdapter.getPrice(DataAdapter.java:242)

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  • Contacts activity doesn't return data

    - by Mike
    In my app I simply open the list of activities and when a contact is clicked I attempt to retrieve the name of the contact selected and put it into a string. The app crashes in the onActivityResult() function. I do have the READ_CONTACTS permission set. /** * Opens the contacts activity */ public void openContacts() { Intent intent = new Intent(Intent.ACTION_PICK, People.CONTENT_URI); startActivityForResult(intent, PICK_CONTACT); } @Override public void onActivityResult(int reqCode, int resultCode, Intent data) { super.onActivityResult(reqCode, resultCode, data); switch (reqCode) { case (PICK_CONTACT) : if (resultCode == Activity.RESULT_OK) { Uri contactData = data.getData(); Cursor c = managedQuery(contactData, null, null, null, null); //NullPointerException thrown here, line 102 if (c.moveToFirst()) { String name = c.getString(c.getColumnIndexOrThrow(People.NAME)); FRIEND_NAME = name; showConfirmDialog(name); } } break; } } The following logcat error logs are returned: Any help is appreciated. Thanks

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  • Is there some way to assume @Nullable as default? (using FindBugs or any other free tool).

    - by alex2k8
    Consider such code public void m1(String text) { if(text == null) text = "<empty>"; System.out.println(text.toLowerCase()); } And this is a buggy version: public void m1(String text) { System.out.println(text.toLowerCase()); } If null value passed, the NullPointerException may be thrown. I would like the static-analysis tool (e.g. FindBugs) to report this issue. Unsuccessfully the FindBugs (at least by default) requires me to specify @Nullable annotation explicitly. public void m1(@Nullable String text) { System.out.println(text.toLowerCase()); // FindBugs: text must be nonnull but is marked as nullable } The problem is that if I forget to annotate it, the bug will be missed!!! How can I make the FindBugs (or any other free tool) to assume @Nullable by default?

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  • Use nested static class as ActionListener for the Outer class

    - by Digvijay Yadav
    I want to use an nested static class as an actionListener for the enclosing class's GUI elements. I did something like this: public class OuterClass { public static void myImplementation() { OuterClass.StartupHandler startupHandler = new OuterClass.StartupHandler(); exitMenuItem.addActionListener(startupHandler); // error Line } public static class StartupHandler implements ActionListener { @Override public void actionPerformed(ActionEvent e) { //throw new UnsupportedOperationException("Not supported yet."); if (e.getSource() == exitMenuItem) { System.exit(1); } else if (e.getSource() == helpMenuItem) { // show help menu } } } } But when I invoke this code I get the NullPointerException at the //error Line. Is this the right method to do do this or there is something I did am missing?

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  • Reference variable to an object instantiated/initialized in another class in Java

    - by Alex
    The reason I'm asking is because I'm getting NullPointerException. I now this is very easy but I'm pretty new programming and find this a bit confusing. So say I have initialized an object in a class and want to access that same object from another class. Like now for instance I'm working on a small Chess game, in my model Game class I have an instance of Board, an object. Board, in turn, has an array of Squares. Square[][]. Game has board, board has Square[][]. Now if I want to access the Square[][] through the object board (in Game) of type Board. Do I just declare a variable with the same name and type or do I have to initialize it again? Board board OR Board board = new Board(); Note, I have already initialized board in the class Game so if I do it again, won't they be two totally different Board objects?

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  • Can a plain servlet be configured as a seam component?

    - by stacker
    I created a plain servlet within a seam-gen (2.1.2) application, now I would like to use injection. Thus I annotated it with @Name and it's recognized as component: INFO [Component] Component: ConfigReport, scope: EVENT, type: JAVA_BEAN, class: com.mycompany.servlet.ConfigReport Unfortunatly the injection of the logger doesn't work NullPointerException in init() import org.jboss.seam.annotations.Logger; import org.jboss.seam.annotations.Name; import org.jboss.seam.log.Log; @Name("ConfigReport") public class ConfigReport extends HttpServlet { @Logger private Log log; public void init(ServletConfig config) throws ServletException { log.info( "BOOM" ); } } Is my approach abusive? What would be the alternatives (the client sending requests to the servlet is curl, not a browser)?

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  • How to acquire the Context in an Adobe AIR Native Extension?

    - by rotaercz
    In the following line of code... ProgressDialog progressDialog = ProgressDialog.show(getBaseContext(), "LOADING_TITLE", "LOADING_MESSAGE"); In place of getBaseContext() I've tried... getApplicationContext() this NativeActivity.this (NativeActivity)getApplicationContext() Among others. I'm not sure why it's not working. In the NativeExtensionContext which extends FREContext I am passing the activity using getActivity() to NativeActivity. Everything works well but I get a "Nullpointerexception" or “android.view.WindowManager$BadTokenException: Unable to add window — token null is not for an application” when I try I try to get a reference to the Context. Anyone with experience using Adobe AIR Native Extensions and/or Android Java would be great.

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  • Eclipse bug? Switching on a null with only default case

    - by polygenelubricants
    I was experimenting with enum, and I found that the following compiles and runs fine on Eclipse (Build id: 20090920-1017, not sure exact compiler version): public class SwitchingOnAnull { enum X { ,; } public static void main(String[] args) { X x = null; switch(x) { default: System.out.println("Hello world!"); } } } When compiled and run with Eclipse, this prints "Hello world!" and exits normally. With the javac compiler, this throws a NullPointerException as expected. So is there a bug in Eclipse Java compiler?

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