android - Java.lang.classcastexception：android.app.application

Question

我的问题是这样的：我正在尝试运行程序代码 soundclouddroid 1.2.2。https://code.google.com/p/soundclouddroid/source/browse/ 但是在运行程序时出现错误： java.lang.RuntimeException: Unable to resume activity {es.manu.sd122.soundCloudDroid/es.manu.sd122.soundCloudDroid.SoundCloudDroid}: java.lang.ClassCastException: android . app.Application

我不明白您为什么会收到此错误，我没有更改 code.google 上提供的代码。

你能帮助我吗？我很绝望。谢谢。

My logcat

10-17 07:29:33.171: I/ActivityThread(327): Pub org.urbanstew.provider.soundclouddroid: es.manu.sd122.soundCloudBase.SoundCloudData
10-17 07:29:33.481: D/AndroidRuntime(327): Shutting down VM
10-17 07:29:33.481: W/dalvikvm(327): threadid=1: thread exiting with uncaught exception (group=0x40015560)
10-17 07:29:33.491: E/AndroidRuntime(327): FATAL EXCEPTION: main
10-17 07:29:33.491: E/AndroidRuntime(327): java.lang.RuntimeException: Unable to resume activity {es.manu.sd122.soundCloudDroid/es.manu.sd122.soundCloudDroid.SoundCloudDroid}: java.lang.ClassCastException: android.app.Application
10-17 07:29:33.491: E/AndroidRuntime(327):  at  android.app.ActivityThread.performResumeActivity(ActivityThread.java:2120)
10-17 07:29:33.491: E/AndroidRuntime(327):  at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2135)
10-17 07:29:33.491: E/AndroidRuntime(327):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1668)
10-17 07:29:33.491: E/AndroidRuntime(327):  at android.app.ActivityThread.access$1500(ActivityThread.java:117)
10-17 07:29:33.491: E/AndroidRuntime(327):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
10-17 07:29:33.491: E/AndroidRuntime(327):  at android.os.Handler.dispatchMessage(Handler.java:99)
10-17 07:29:33.491: E/AndroidRuntime(327):  at android.os.Looper.loop(Looper.java:123)
10-17 07:29:33.491: E/AndroidRuntime(327):  at android.app.ActivityThread.main(ActivityThread.java:3683)
10-17 07:29:33.491: E/AndroidRuntime(327):  at java.lang.reflect.Method.invokeNative(Native Method)
10-17 07:29:33.491: E/AndroidRuntime(327):  at java.lang.reflect.Method.invoke(Method.java:507)
10-17 07:29:33.491: E/AndroidRuntime(327):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
10-17 07:29:33.491: E/AndroidRuntime(327):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
10-17 07:29:33.491: E/AndroidRuntime(327):  at dalvik.system.NativeStart.main(Native Method)
10-17 07:29:33.491: E/AndroidRuntime(327): Caused by: java.lang.ClassCastException: android.app.Application
10-17 07:29:33.491: E/AndroidRuntime(327):  at es.manu.sd122.soundCloudBase.SoundCloudBaseActivity.getSoundCloudAPI(SoundCloudBaseActivity.java:16)
10-17 07:29:33.491: E/AndroidRuntime(327):  at es.manu.sd122.soundCloudBase.SoundCloudMainActivity.updateAuthorizationStatus(SoundCloudMainActivity.java:139)
10-17 07:29:33.491: E/AndroidRuntime(327):  at es.manu.sd122.soundCloudBase.SoundCloudMainActivity.onResume(SoundCloudMainActivity.java:91)
10-17 07:29:33.491: E/AndroidRuntime(327):  at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1150)
10-17 07:29:33.491: E/AndroidRuntime(327):  at android.app.Activity.performResume(Activity.java:3832)
10-17 07:29:33.491: E/AndroidRuntime(327):  at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2110)
10-17 07:29:33.491: E/AndroidRuntime(327):  ... 12 more
10-17 08:28:24.151: I/Process(327): Sending signal. PID: 327 SIG: 9

错误所在的代码：

SoundCloudBaseActivity.java:

package es.manu.sd122.soundCloudBase;



import org.urbanstew.soundcloudapi.SoundCloudAPI;

import android.app.Activity;



public class SoundCloudBaseActivity extends Activity
{

public SoundCloudAPI getSoundCloudAPI()
{

    return ((SoundCloudApplicationBase)getApplication()).getSoundCloudAPI();//error line 16

}

public SoundCloudApplicationBase getSCApplicationBase()
{
    return (SoundCloudApplicationBase)getApplication();
}
}

SoundCloudMainActivity.java:

public class SoundCloudMainActivity extends SoundCloudBaseActivity implements SoundCloudRequestClient
{
.
.
.
.
 public void onResume()
{
    super.onResume();
    updateAuthorizationStatus();//error line 91
}
.
.
.
.
public void updateAuthorizationStatus()
{
    int text;

    if(getSoundCloudAPI().getState() == SoundCloudAPI.State.AUTHORIZED)//error linea 139
    {
        if(mUserName != null)
        {
            setUserName(mUserName);
            return;
        }
        getSCApplicationBase().processRequest("me", this);
        text = R.string.verifying_connection;
    }
    else
    {
        text = R.string.please_connect;
    }

    mAuthorized.setText(text);
}

文件清单

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="es.manu.sd122.soundCloudDroid"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk
    android:minSdkVersion="10"
    android:targetSdkVersion="10" />
<uses-permission android:name="android.permission.INTERNET"></uses-permission>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>

<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <!--   <provider android:name="es.manu.sd122.soundCloudBase.SoundCloudData" android:authorities="es.manu.sd122.provider.soundclouddroid">
        </provider>
-->
<provider android:name="es.manu.sd122.soundCloudBase.SoundCloudData" android:authorities="org.urbanstew.provider.soundclouddroid">
        </provider>

    <activity
        android:name="es.manu.sd122.soundCloudBase.ObtainAccessToken"
        android:configChanges="keyboardHidden|orientation"
        android:label="Connect with SoundCloud">
    </activity>

    <activity
        android:name="es.manu.sd122.soundCloudBase.ViewTracksActivity"          
        android:launchMode="singleTask"
        android:configChanges="keyboardHidden|orientation"          
        android:allowTaskReparenting="true" android:label="My Tracks">      
    </activity>

    <service android:name="es.manu.sd122.soundCloudBase.SoundCloudService"></service>



    <activity
        android:name="es.manu.sd122.soundCloudDroid.SoundCloudDroid"
        android:label="@string/app_name" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>

     <activity
        android:name="es.manu.sd122.soundCloudDroid.UploadActivity"
        android:label="Upload File To SoundCloud">
        <intent-filter>
            <action android:name="android.intent.action.SEND"></action>
            <data android:mimeType="audio/*"></data>
            <category android:name="android.intent.category.DEFAULT"/>
        </intent-filter>
        <intent-filter>
            <action android:name="android.intent.action.VIEW"></action>
            <category android:name="android.intent.category.DEFAULT"></category>
            <data android:mimeType="vnd.android.cursor.item/es.manu.sd122.soundCloudDroid.UploadsActivity"></data>
        </intent-filter>
    </activity>


     <activity
        android:name="es.manu.sd122.soundCloudDroid.UploadsActivity"
        android:launchMode="singleTop"
        android:allowTaskReparenting="true" android:label="View Upload Status">
    </activity>

      <activity
        android:name="es.manu.sd122.soundCloudDroid.ViewTracksActivity"
        android:launchMode="singleTask"
        android:configChanges="keyboardHidden|orientation"
        android:allowTaskReparenting="true" android:label="My Tracks">
    </activity>

    <activity
        android:name="es.manu.sd122.soundCloudDroid.ViewOtherTracksActivity"
        android:launchMode="singleTask"
        android:configChanges="keyboardHidden|orientation"
        android:allowTaskReparenting="true" android:label="My Favorites">
    </activity>

    <activity
        android:name="es.manu.sd122.soundCloudDroid.CustomTrackListsActivity"
        android:launchMode="singleTask"
        android:configChanges="keyboardHidden|orientation"
        android:allowTaskReparenting="true" android:label="Track Lists">
    </activity>

    <activity
        android:name="es.manu.sd122.soundCloudDroid.NewArtistTracksActivity"
        android:launchMode="singleTask"
        android:configChanges="keyboardHidden|orientation"
        android:allowTaskReparenting="true" android:label="Search for Artists">
    </activity>


</application>

如果您还需要什么，请随时询问。再次感谢你。

Answer 1

如果您创建了自定义应用程序类型，则需要在清单中指定它：

<application
    android:name="es.manu.sd122.soundCloudBase.SoundCloudApplicationBase"

希望这可以帮助 ：）

Answer 2

我认为，在这里你需要返回SoundCloudAPI对象但你返回SoundCloudApplicationBase，

public SoundCloudAPI getSoundCloudAPI()
{

    return ((SoundCloudApplicationBase)getApplication()).getSoundCloudAPI();//error line 16

}

所以尝试这样做，

 public SoundCloudAPI getSoundCloudAPI()
    {

        return ((SoundCloudAPI)getApplication()).getSoundCloudAPI();//error line 16

    }

Answer 3

您已经发布了 SoundCloud库项目的清单代码，这表明您可能正在尝试直接运行它。这不是它的预期工作方式。

相反，请检查SoundCloudBase和SoundCloudDroid，并确保前者设置为Android 库项目，并且后者具有对它的引用。之后，运行SoundCloudDroid. 正如您在该项目的清单中看到的那样，它正确地声明了应用程序的“名称”属性，该属性是Application在运行时实例化的扩展类：

android:name="SoundCloudApplication"

如果您不知道如何设置SoundCloudBase为 Android 库项目，请查看此处：

• http://developer.android.com/tools/projects/projects-eclipse.html#SettingUpLibraryProject
• http://developer.android.com/tools/projects/index.html#LibraryProjects

---

编辑：看起来我最初的陈述并不完全正确，因为清单不是包含在SoundCloudBase. 但是，它缺少应用程序名称属性，这是引发异常的直接原因。您需要更改的只是添加该属性并确保它指向正确的位置（即，如果您不确定，请使用完全限定的路径名​​），这并非不可能。

Answer 4

应用程序类不能通过类型转换转换为其他类型。