android - java.lang.RuntimeException : Unable to instantiate activity ComponentInfo . ... java.lang.ClassNotFoundException 异常

Question

三天以来我一直在处理一个问题，我尝试阅读不同的答案，但没有帮助。有人也可以帮帮我吗!!我将 Ancdroid 应用程序编写为 restful web 服务的客户端。我可以毫无问题地从数据库中获取数据，但我的问题是我用来处理从数据库中获取的文件的 2 个 Activity 。

主要 Activity

public class MainActivity extends Activity  {



private static final String SERVICE_URL = "http://10.0.2.2:8080/.....";
private static final String TAG = "AndroidRESTClientActivity";   
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    public void retrieveSampleData(View vw) {
        EditText idTxt = (EditText) findViewById(R.id.id_textfield);
        String id = idTxt.getText().toString();
        String sampleURL = SERVICE_URL +"daten/"+id ;

        Log.d("getrespond()", "service calling");
String url =sampleURL;

                       RestClient client = new RestClient(url);

                       try{
                           client.Execute(RestClient.RequestMethod.GET,this.getApplicationContext());
                       }
                       catch (Exception e) {

                           String error = String.valueOf(e);
                                Log.d("**********client.Execute(RequestMethod.GET);***********",error);    

                       }

                       try {

                           if(client.getResponseCode() == 200) {

                               Log.d("Response is 200", String.valueOf(client.getResponse().length()));
                               System.out.println(this.getFilesDir().getPath().toString());
                               File daten= client.getResponse();
                                  System.out.println(daten.getName());                       

                               Toast.makeText(this.getApplicationContext(), "Responce is "+String.valueOf(client.getResponseCode()), 2000).show();                            

                       }  else {
                               String error = String.valueOf(client.getResponse());
                               Log.d("Response*********** not 200 ************", String.valueOf(client.getResponse()));

                           }

                       }catch (Exception e) {
                           e.printStackTrace();
                            Log.d("EXCEPTIONI IS 3", e.toString());
                           // TODO: handle exception
                       }
                       startActivity(new Intent("android.intent.action.LINEGRAPH"));

我从主要开始的其他 Activity :

public class lineGraph extends Activity{



       @Override
    public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);             
            setContentView(R.layout.activity_line_graph);
       }

       @Override
    protected void onResume() { 
           super.onResume(); 
           if (mChartView == null) { 
             LinearLayout layout = (LinearLayout) findViewById(R.id.chart); 
             try {
                mChartView = ChartFactory.getLineChartView(this, getDemoDataset(), 
                        getDemoRenderer());
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } 
             layout.addView(mChartView, new LayoutParams 
         (LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT)); 

           } else { 
             mChartView.repaint(); 
           } 
         }

list .xml

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.praktikum.androidcrestclient"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="15" />

    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" >
    </uses-permission>
    <uses-permission android:name="android.permission.INTERNET" >
    </uses-permission>
    <uses-permission android:name="android.permission.WRITE_INTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.READ_CONTACTS" />
    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"
            android:label="@string/title_activity_main" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name="com.praktikum.androidcrestclient.LineGraph"
            android:label="@string/title_activity_line_graph" >
            <intent-filter>
                <action android:name="android.intent.action.LINEGRAPH" />
                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </activity>
        <activity android:name="org.achartengine.GraphicalActivity"/>
    </application>

</manifest>

这是我的 LogCat

10-08 09:23:10.140: D/AndroidRuntime(4706): Shutting down VM
10-08 09:23:10.140: W/dalvikvm(4706): threadid=1: thread exiting with uncaught exception (group=0x40015560)
10-08 09:23:10.161: E/AndroidRuntime(4706): FATAL EXCEPTION: main
10-08 09:23:10.161: E/AndroidRuntime(4706): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.praktikum.androidcrestclient/com.praktikum.androidcrestclient.LineGraph}: java.lang.ClassNotFoundException: com.praktikum.androidcrestclient.LineGraph in loader dalvik.system.PathClassLoader[/data/app/com.praktikum.androidcrestclient-1.apk]
10-08 09:23:10.161: E/AndroidRuntime(4706):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1569)
10-08 09:23:10.161: E/AndroidRuntime(4706):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
10-08 09:23:10.161: E/AndroidRuntime(4706):     at android.app.ActivityThread.access$1500(ActivityThread.java:117)
10-08 09:23:10.161: E/AndroidRuntime(4706):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
10-08 09:23:10.161: E/AndroidRuntime(4706):     at android.os.Handler.dispatchMessage(Handler.java:99)
10-08 09:23:10.161: E/AndroidRuntime(4706):     at android.os.Looper.loop(Looper.java:123)
10-08 09:23:10.161: E/AndroidRuntime(4706):     at android.app.ActivityThread.main(ActivityThread.java:3683)
10-08 09:23:10.161: E/AndroidRuntime(4706):     at java.lang.reflect.Method.invokeNative(Native Method)
10-08 09:23:10.161: E/AndroidRuntime(4706):     at java.lang.reflect.Method.invoke(Method.java:507)
10-08 09:23:10.161: E/AndroidRuntime(4706):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
10-08 09:23:10.161: E/AndroidRuntime(4706):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
10-08 09:23:10.161: E/AndroidRuntime(4706):     at dalvik.system.NativeStart.main(Native Method)
10-08 09:23:10.161: E/AndroidRuntime(4706): Caused by: java.lang.ClassNotFoundException: com.praktikum.androidcrestclient.LineGraph in loader dalvik.system.PathClassLoader[/data/app/com.praktikum.androidcrestclient-1.apk]
10-08 09:23:10.161: E/AndroidRuntime(4706):     at dalvik.system.PathClassLoader.findClass(PathClassLoader.java:240)
10-08 09:23:10.161: E/AndroidRuntime(4706):     at java.lang.ClassLoader.loadClass(ClassLoader.java:551)
10-08 09:23:10.161: E/AndroidRuntime(4706):     at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
10-08 09:23:10.161: E/AndroidRuntime(4706):     at android.app.Instrumentation.newActivity(Instrumentation.java:1021)
10-08 09:23:10.161: E/AndroidRuntime(4706):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1561)
10-08 09:23:10.161: E/AndroidRuntime(4706):     ... 11 more
10-08 09:23:10.180: W/ActivityManager(89):   Force finishing activity com.praktikum.androidcrestclient/.LineGraph
10-08 09:23:10.180: W/ActivityManager(89):   Force finishing activity com.praktikum.androidcrestclient/.MainActivity
10-08 09:23:10.690: W/ActivityManager(89): Activity pause timeout for HistoryRecord{4094eea0 com.praktikum.androidcrestclient/.LineGraph}
10-08 09:23:12.330: I/Process(4706): Sending signal. PID: 4706 SIG: 9
10-08 09:23:12.350: I/ActivityManager(89): Process com.praktikum.androidcrestclient (pid 4706) has died.
10-08 09:23:12.360: E/InputDispatcher(89): channel '4065ae98 com.praktikum.androidcrestclient/com.praktikum.androidcrestclient.MainActivity (server)' ~ Consumer closed input channel or an error occurred.  events=0x8
10-08 09:23:12.360: E/InputDispatcher(89): channel '4065ae98 com.praktikum.androidcrestclient/com.praktikum.androidcrestclient.MainActivity (server)' ~ Channel is unrecoverably broken and will be disposed!
10-08 09:23:12.490: I/WindowManager(89): WIN DEATH: Window{4065ae98 com.praktikum.androidcrestclient/com.praktikum.androidcrestclient.MainActivity paused=true}
10-08 09:23:12.500: I/WindowManager(89): WIN DEATH: Window{406c1140 Toast paused=false}
10-08 09:23:12.600: W/InputManagerService(89): Got RemoteException sending setActive(false) notification to pid 4706 uid 10034
10-08 09:23:12.660: E/InputDispatcher(89): Received spurious receive callback for unknown input channel.  fd=168, events=0x8
10-08 09:23:16.820: D/dalvikvm(396): GC_EXPLICIT freed 7K, 54% free 2537K/5511K, external 1625K/2137K, paused 43ms
10-08 09:23:21.626: W/ActivityManager(89): Activity destroy timeout for HistoryRecord{4094e768 com.praktikum.androidcrestclient/.MainActivity}
10-08 09:23:21.626: W/ActivityManager(89): Activity destroy timeout for HistoryRecord{4094eea0 com.praktikum.androidcrestclient/.LineGraph}
10-08 09:23:21.900: D/dalvikvm(299): GC_EXPLICIT freed 12K, 55% free 2589K/5703K, external 1625K/2137K, paused 73ms
10-08 09:23:26.950: D/dalvikvm(407): GC_EXPLICIT freed 4K, 55% free 2532K/5511K, external 1625K/2137K, paused 57ms
10-08 09:24:54.097: D/SntpClient(89): request time failed: java.net.SocketException: Address family not supported by protocol
10-08 09:29:54.106: D/SntpClient(89): request time failed: java.net.SocketException: Address family not supported by protocol
10-08 09:34:54.130: D/SntpClient(89): request time failed: java.net.SocketException: Address family not supported by protocol

能否请您帮我找出为什么找不到其他 Activity 。

谢谢

Answer 1

在此声明中将类的名称更改为“LineGraph”而不是“lineGraph”:

public class LineGraph extends Activity{