标签: classcastexception

运行以下应用程序时,我有以下异常

活动:

package com.google.android.SmartStudentmCompanion;


import java.io.BufferedReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class Login extends  Activity{
    public static String ip_address="192.168.1.101";

    EditText username; 
    EditText password;
    Button login;
    Button exit;
    Toast toast;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.loginscreen);
        System.out.println("onCreate()...");
        username = (EditText) …

几天后我遇到了一个大问题:当我尝试在布局和我的自定义surfaceview上绑定surfaceview时,我从自定义surfaceview获得了ClassCastException.

这是我的代码:

public void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
     setContentView(R.layout.main);
     waveform =(WaveFormView) findViewById(R.id.surfaceView1);
}
class WaveFormView extends SurfaceView implements SurfaceHolder.Callback {        
    public WaveFormView(Context context, AttributeSet attrs) {
        super(context, attrs);
        getHolder().addCallback(this);
        _dthread = new DrawingThread(getHolder(), this);
        setFocusable(true);
        paintP.setStyle(Paint.Style.STROKE);
        paintP.setStrokeWidth(1);
        paintP.setColor(Color.WHITE);
        paintT.setStyle(Paint.Style.STROKE);
        paintT.setStrokeWidth(1);
        paintT.setColor(Color.WHITE);
    }

    @Override
    public void onDraw(Canvas canvas) {
        canvas.drawColor(Color.BLACK);
        for (int i=0;i<_athread.buffer.length-pas;i+=pas){
            canvas.drawLine(i, 150-_athread.buffer[i], i+pas, 150-_athread.buffer[i+pas], paintP);
        }
        canvas.drawText("FPS:  " + String.valueOf(FPS), 0, 10, paintT);
        //canvas.drawText("tmp:  " + tmp, 0, 20, paintT);
    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, …

这是我第一次真正使用列表和队列,所以这可能是一个非常简单的错误.是因为我的队列中充满了无法转换为整数的对象吗？

           //populate array
        for(int i=0; i<11; i++){
            numberarray[i] = i; 
        }
        // populate list with numbers from array
        List numList = Arrays.asList(numberarray);
        Collections.shuffle(numList);

        Queue queue = new LinkedList();
        queue.addAll(numList);

        int num1 = (Integer) queue.poll();
        assignPictures(button01, num1);

我在尝试执行更新语句(UpdateUser)时在MyBatis中收到此异常:

java.lang.ClassCastException: java.lang.Integer cannot be cast to java.lang.Boolean
at $Proxy6.updateUser(Unknown Source)
at com.nortal.pirs.persistence.dbmybatis.UserDaoMyBatisImpl.updateUser(UserDaoMyBatisImpl.java:60)
at com.nortal.pirs.test.persistence.UserDaoAbstractTest.testUpdateUser(UserDaoAbstractTest.java:117)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:45)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:42)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:28)
at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:30)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:263)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:68)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:47)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:231)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:60)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:50)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:222)
at org.junit.runners.ParentRunner.run(ParentRunner.java:300)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)

我的数据类型我正在使用的用户看起来像这样:

public class User {
private String firstName = "";
private …

我目前试着问一个演员并在事后做"onComplete".

这是我的例子:

(此代码段包含在方法中)

(receivingActor ? message).mapTo[ReturnMessage].onComplete {
  case Success(rm) =>
    rm.getEitherObjectOrError() match {
      case Left(a) => return a
      case Right(e) =>
        sender ! ReturnMessage(None, Some(e))
        context.stop(self)
    }
  case Failure ... (doesnt matter)
}

当我尝试将我的任何对象转换为期望的类型时......

any.asInstanceOf[ExpectedType]

...我收到以下异常:

 ERROR akka.actor.OneForOneStrategy - scala.runtime.BoxedUnit cannot be cast to ExpectedType
 java.lang.ClassCastException: scala.runtime.BoxedUnit cannot be cast to ExpectedType

通常我会期待任何类型为"任何"的对象,所以...我错过了什么？

提前致谢

尝试使用RoundedDrawable类(从https://github.com/vinc3m1/RoundedImageView获取)插入并映像到Rounded图像.

图像来自URL.如果我使用Koushik dutta的ION库作为图像加载部分,我会收到以下错误:

 09-27 21:35:06.187: E/AndroidRuntime(12606): FATAL EXCEPTION: main
 09-27 21:35:06.187: E/AndroidRuntime(12606): Process: com.ylg.maps, PID: 12606
 09-27 21:35:06.187: E/AndroidRuntime(12606): java.lang.ClassCastException: com.koushikdutta.ion.IonDrawable cannot be cast to android.graphics.drawable.BitmapDrawable
 09-27 21:35:06.187: E/AndroidRuntime(12606):   at com.ylg.otherlibs.RoudImageViewForMap.loadBitmap(RoudImageViewForMap.java:70)
 09-27 21:35:06.187: E/AndroidRuntime(12606):   at com.ylg.otherslibs.RoudImageViewForMap.onDraw(RoudImageViewForMap.java:80)
 09-27 21:35:06.187: E/AndroidRuntime(12606):   at android.view.View.draw(View.java:14465)
 09-27 21:35:06.187: E/AndroidRuntime(12606):   at android.view.View.draw(View.java:14350)
 09-27 21:35:06.187: E/AndroidRuntime(12606):   at android.view.ViewGroup.drawChild(ViewGroup.java:3103)
 09-27 21:35:06.187: E/AndroidRuntime(12606):   at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2940)
 09-27 21:35:06.187: E/AndroidRuntime(12606):   at android.view.View.buildDrawingCache(View.java:13673)
 09-27 21:35:06.187: E/AndroidRuntime(12606):   at android.view.View.buildDrawingCache(View.java:13522)
 09-27 21:35:06.187: E/AndroidRuntime(12606):   at com.ylg.maps.Mapsthree.createDrawableFromView(Mapsthree.java:454)
 09-27 21:35:06.187: E/AndroidRuntime(12606):   at com.ylg.maps.Mapsthree.loadFriends(Mapsthree.java:417)
 09-27 21:35:06.187: …

我正进入(状态

java.lang.ClassCastException: java.util.HashMap cannot be cast to java.util.LinkedHashMap

在LinkedHashMap<String, String> dataHashMap = (LinkedHashMap<String, String>) intent.getSerializableExtra("tests.test.MyApp.A.EXTRA_KEY");活动B的代码(相关部分)中.

1. 在片段A中,我有以下检查:

   Log.i(TAG, "THE TYPE OF THE MAP RETURNED FROM populateSelectedEntryList(selectedResultEntry) IS " + 
   populateSelectedEntryList(selectedResultEntry).getClass().getSimpleName()
   + ".");//******PRINTS LinkedHashMap**********************
   

   Run Code Online (Sandbox Code Playgroud)

其打印LinkedHashMap.

2. 在活动B中,我有以下检查:

   LinkedHashMap<String, String> dataHashMap = (LinkedHashMap<String, String>)intent.getSerializableExtra("tests.test.MyApp.A.EXTRA_KEY");//**********ClassCastException*****************
   

   Run Code Online (Sandbox Code Playgroud)

   其打印HashMap.

   ---

问题是为什么？为什么系统将LinkedHashMap转换为HashMap.当作为Serializable在intent中传递LinkedHashMap时,如何强制LinkedHashMap继续成为LinkedHashMap？

相关部分代码:

在片段A中,

public class A extends Fragment {
  ...

  public void onListItemClick(...) { 
    Intent intent = new Intent(getActivity(), B.class);
    ...
    intent.putExtra("tests.test.MyApp.A.EXTRA_KEY", populateSelectedEntryList(selectedResultEntry));
    Log.i(TAG, "THE TYPE OF THE MAP RETURNED …

我为后台进程创建了一个单独的类.在那,我有两个类和一个接口.我从第一个类中获取字符串数据,然后根据该数据获取另一个类中的数据列表.整个过程工作正常,但现在我想将该列表发送到我的片段但是得到了java.lang.ClassCastException

以下是我的代码: -

public class PlacesTaskNew extends AsyncTask<String, Void, String> {

    Context context;

    public PlacesTaskNew(Context context) {
        this.context = context;
    }

    @Override
    protected String doInBackground(String... place) {

        String data = "";
        -- --
        return data;
    }

    @Override
    protected void onPostExecute(String result) {
        super.onPostExecute(result);
        ParserTask parserTask = new ParserTask(context);
        parserTask.execute(result);
    }

    private String downloadUrl(String strUrl) throws IOException {

        String data = "";
        -- --
        return data;
    }

    public interface PlaceTaskInterface {
        void onGetPlaces(List<HashMap<String, String>> result, String[] from, int[] to);
    } …

这段代码使我感到恼火，有时它起作用，而另一些时候却不起作用！

NamedQuery ：（名称=“ User.findByLogin”，查询=“从用户u在哪里选择u.login =：login”）

public User findByLogin(String login) {
        Query query = em.createNamedQuery("User.findByLogin");
        query.setParameter("login", login);
        try {
            return (User) query.getSingleResult();
        } catch (javax.persistence.NoResultException ex) {
            return null;
        }
    }

错误使我发疯！

Avertissement：EJB5184：在EJB UserFacade上调用期间发生系统异常，方法：public dz.admin.entity.User dz.admin.service.UserFacade.findByLogin（java.lang.String）Avertissement：javax.ejb.EJBException .. .. 由以下原因引起：java.lang.ClassCastException：dz.elit.admin.entity.User无法转换为dz.elit.admin.service.UserFacade.findByLogin（UserFacade.java： 45）

我正在尝试使用Hibernate和HQL查询来计算行数.我写了以下代码:

public long countTexteEstALOrdreDuJour(String examenId) throws DAOException {
    StringBuilder hqlQuery = new StringBuilder();
    hqlQuery.append("SELECT count(*) ")
        .append("FROM Examen as e ")
        .append("JOIN e.organeSaisi as os ")
        .append("JOIN os.texteDeLoi as t ")
        .append("WHERE e.organeSaisi = some (SELECT ex.organeSaisi FROM Examen as ex WHERE ex.id = :examenId) ")
        .append("AND e.examenEstALOrdreDuJour = 1 ");

    try {
        Query query = this.getSession().createQuery(hqlQuery.toString());
        query.setParameter("examenId", examenId);

        String result = (String)query.uniqueResult();
        Long ret = null;

        if (result==null) {
            ret = 0l;
        } else {
            ret = Long.parseLong(result);
        } …