Android 中Crash时如何获取异常信息详解及实例

/** 
 * Sets the default uncaught exception handler. This handler is invoked in 
 * case any Thread dies due to an unhandled exception. 
 * 
 * @param handler 
 *      The handler to set or null. 
 */ 
public static void setDefaultUncaughtExceptionHandler(UncaughtExceptionHandler handler) { 
  Thread.defaultUncaughtHandler = handler; 
} 

public class CrashHandler implements UncaughtExceptionHandler { 
  private static final String TAG = "CrashHandler"; 
  private static final boolean DEBUG = true; 
 
  private static final String PATH = Environment.getExternalStorageDirectory().getPath() + "/ryg_test/log/"; 
  private static final String FILE_NAME = "crash"; 
 
  //log文件的后缀名 
  private static final String FILE_NAME_SUFFIX = ".trace"; 
 
  private static CrashHandler sInstance = new CrashHandler(); 
 
  //系统默认的异常处理（默认情况下，系统会终止当前的异常程序） 
  private UncaughtExceptionHandler mDefaultCrashHandler; 
 
  private Context mContext; 
 
  //构造方法私有，防止外部构造多个实例，即采用单例模式 
  private CrashHandler() { 
  } 
 
  public static CrashHandler getInstance() { 
    return sInstance; 
  } 
 
  //这里主要完成初始化工作 
  public void init(Context context) { 
    //获取系统默认的异常处理器 
    mDefaultCrashHandler = Thread.getDefaultUncaughtExceptionHandler(); 
    //将当前实例设为系统默认的异常处理器 
    Thread.setDefaultUncaughtExceptionHandler(this); 
    //获取Context，方便内部使用 
    mContext = context.getApplicationContext(); 
  } 
 
  /** 
   * 这个是最关键的函数，当程序中有未被捕获的异常，系统将会自动调用#uncaughtException方法 
   * thread为出现未捕获异常的线程，ex为未捕获的异常，有了这个ex，我们就可以得到异常信息。 
   */ 
  @Override 
  public void uncaughtException(Thread thread, Throwable ex) { 
    try { 
      //导出异常信息到SD卡中 
      dumpExceptionToSDCard(ex); 
      //这里可以通过网络上传异常信息到服务器，便于开发人员分析日志从而解决bug 
      uploadExceptionToServer(); 
    } catch (IOException e) { 
      e.printStackTrace(); 
    } 
 
    //打印出当前调用栈信息 
    ex.printStackTrace(); 
 
    //如果系统提供了默认的异常处理器，则交给系统去结束我们的程序，否则就由我们自己结束自己 
    if (mDefaultCrashHandler != null) { 
      mDefaultCrashHandler.uncaughtException(thread, ex); 
    } else { 
      Process.killProcess(Process.myPid()); 
    } 
 
  } 
 
  private void dumpExceptionToSDCard(Throwable ex) throws IOException { 
    //如果SD卡不存在或无法使用，则无法把异常信息写入SD卡 
    if (!Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) { 
      if (DEBUG) { 
        Log.w(TAG, "sdcard unmounted,skip dump exception"); 
        return; 
      } 
    } 
 
    File dir = new File(PATH); 
    if (!dir.exists()) { 
      dir.mkdirs(); 
    } 
    long current = System.currentTimeMillis(); 
    String time = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date(current)); 
    //以当前时间创建log文件 
    File file = new File(PATH + FILE_NAME + time + FILE_NAME_SUFFIX); 
 
    try { 
      PrintWriter pw = new PrintWriter(new BufferedWriter(new FileWriter(file))); 
      //导出发生异常的时间 
      pw.println(time); 
 
      //导出手机信息 
      dumpPhoneInfo(pw); 
 
      pw.println(); 
      //导出异常的调用栈信息 
      ex.printStackTrace(pw); 
 
      pw.close(); 
    } catch (Exception e) { 
      Log.e(TAG, "dump crash info failed"); 
    } 
  } 
 
  private void dumpPhoneInfo(PrintWriter pw) throws NameNotFoundException { 
    //应用的版本名称和版本号 
    PackageManager pm = mContext.getPackageManager(); 
    PackageInfo pi = pm.getPackageInfo(mContext.getPackageName(), PackageManager.GET_ACTIVITIES); 
    pw.print("App Version: "); 
    pw.print(pi.versionName); 
    pw.print('_'); 
    pw.println(pi.versionCode); 
 
    //android版本号 
    pw.print("OS Version: "); 
    pw.print(Build.VERSION.RELEASE); 
    pw.print("_"); 
    pw.println(Build.VERSION.SDK_INT); 
 
    //手机制造商 
    pw.print("Vendor: "); 
    pw.println(Build.MANUFACTURER); 
 
    //手机型号 
    pw.print("Model: "); 
    pw.println(Build.MODEL); 
 
    //cpu架构 
    pw.print("CPU ABI: "); 
    pw.println(Build.CPU_ABI); 
  } 
 
  private void uploadExceptionToServer() { 
    //TODO Upload Exception Message To Your Web Server 
  } 
 
} 

public class TestApp extends Application { 
 
  private static TestApp sInstance; 
 
  @Override 
  public void onCreate() { 
    super.onCreate(); 
    sInstance = this; 
 
    //在这里为应用设置异常处理程序，然后我们的程序才能捕获未处理的异常 
    CrashHandler crashHandler = CrashHandler.getInstance(); 
    crashHandler.init(this); 
  } 
 
  public static TestApp getInstance() { 
    return sInstance; 
  } 
 
} 

public class CrashActivity extends Activity implements OnClickListener{ 
 
  private Button mButton; 
 
  @Override 
  protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_crash); 
    initView(); 
  } 
 
  private void initView() { 
    mButton = (Button)findViewById(R.id.button1); 
    mButton.setOnClickListener(this); 
  } 
 
  @Override 
  public void onClick(View v) { 
    if (v == mButton) { 
      //在这里默认异常抛出情况，人为抛出一个运行时异常 
      throw new RuntimeException("自定义异常：这是自己抛出的异常"); 
    } 
     
  } 
}