捕获异常信息_UncaughtExceptionHandler，保存日志到本地及发送服务器

当程序崩溃（Crash）的时候，默认是不对异常信息做处理的。如果想要把异常信息保存到本地文件中，或上传的服务器。那么就要借助UncaughtExceptionHandler这个类。

首先，实例化UncaughtExceptionHandler，代码如下：

 public class ForceCloseHandler implements Thread.UncaughtExceptionHandler {

     public static final String LOG_FILE_NAME = "forceclose.log";

     private static ForceCloseHandler inst ;
     public static ForceCloseHandler getInstance() {
         if(inst==null)inst = new ForceCloseHandler();
         return inst;
     }


     private Context mContext;
     private Thread.UncaughtExceptionHandler mExceptionHandler;
     private JSONObject jsonObject;
     private ForceCloseHandler() {}

     public void init(Context context) {
         mContext = context;
         mExceptionHandler = Thread.getDefaultUncaughtExceptionHandler();
         Thread.setDefaultUncaughtExceptionHandler(this);
     }


     private void handleUncaughtException(Throwable ex) {
         if (ex == null) return;
         try {
             if(jsonObject ==null)jsonObject = new JSONObject();
             saveDeviceInfo();
             saveForceCloseInfo2File(ex);
             // 把异常信息发送到服务器
             ForceCloseFeedBack.getInstance().feedBack(mContext, jsonObject.toString());
         } catch (Exception e) {
             LogUtil.w(e);
         }
     }

     @Override
     public void uncaughtException(Thread thread, Throwable throwable) {
         handleUncaughtException(throwable);
         if (throwable != null) LogUtil.w(throwable);
         mExceptionHandler.uncaughtException(thread, throwable);
     }

     public void saveDeviceInfo() throws JSONException {
         TelephonyManager tm = (TelephonyManager) mContext.getSystemService(Context.TELEPHONY_SERVICE);

         jsonObject.put("platform", "android");
         jsonObject.put("model", Build.MODEL);
         jsonObject.put("trackid", AppConfig.PARTNER_ID);
         jsonObject.put("product", AppConfig.CLIENT_TAG);
         jsonObject.put("os_version", Build.VERSION.RELEASE);
         jsonObject.put("deviceid", DeviceInfo.getDeviceId());
         jsonObject.put("net_type", tm.getNetworkOperator());
         jsonObject.put("timestamp", System.currentTimeMillis());
         jsonObject.put("app_version", Application.getInstance().getVersionCode());
     }

     private void saveForceCloseInfo2File(Throwable ex) throws Exception {
         StringWriter writer = new StringWriter();
         PrintWriter printWriter = new PrintWriter(writer);
         ex.printStackTrace(printWriter);
         Throwable cause = ex.getCause();
         while (cause != null) {
             cause.printStackTrace(printWriter);
             cause = cause.getCause();
         }
         printWriter.close();
         String result = writer.toString() + "\n";
         jsonObject.put("errorDetail", result);

         if (AppConfig.LOG_ERR_SAVE) {
             File file = FileHelper.getDiskCacheDir(mContext, LOG_FILE_NAME);
             FileOutputStream fos = new FileOutputStream(file, true);
             fos.write(jsonObject.toString().getBytes());
             fos.close();
         }
     }

 }

接下来，看看这个实例化后的类怎么使用，代码如下：

 public class Application extends android.app.Application {

     private static Application instance;

     public Context currentContext;

     public static Application getInstance() {
         return instance;
     }

     @Override
     public void onCreate() {
         super.onCreate();
         init();
     }

     public void init() {
         instance = this;

         if (Config.LOG_ERR_FEED) {
             ForceCloseHandler.getInstance().init(instance);
         }
     }

     @Override
     public void onTerminate() {
         super.onTerminate();
     }

     @Override
     public void onLowMemory() {
         super.onLowMemory();
     }

 }

非常简单，只要在指定的Application类的onCreate()回调中，把UncaughtExceptionHandler和Application的实例绑定在一起就可以了。关键代码如下：

 public void init(Context context) {
     mContext = context;
     mExceptionHandler = Thread.getDefaultUncaughtExceptionHandler();
     Thread.setDefaultUncaughtExceptionHandler(this);
 }

这样，如果程序崩溃，错误日志就会被保存在本地，同时又被上传到了服务器。