CrashHandler的应用

 我们知道，不管程序怎么写都很难避免crash,当程序crash时，如果能够获取crash信息，那么开发人员及时修复错误的概率就会大很多。其实我们可以通过CrashHandler来监视应用的crash信息，当程序crash时就会调用uncaughtException方法。

 CrashHandler的创建首先需要实现一个UncaughtExceptionHandler对象，在它的uncaughtException方法中获取异常信息并将其存储在SD卡中或者上传到服务器供开发人员分析，然后调用Thread的setDefaultUncaughtExceptionHandler方法将它设置为线程默认的异常处理器，由于默认异常处理器是Thread类的静态成员，因此它的作用对象就是当前的所有线程。实现如下：

CrashHandler代码：

package com.example.crashhandler;import java.io.BufferedWriter;import java.io.File;import java.io.FileWriter;import java.io.IOException;import java.io.PrintWriter;import java.lang.Thread.UncaughtExceptionHandler;import java.text.SimpleDateFormat;import java.util.Date;import android.content.Context;import android.content.pm.PackageInfo;import android.content.pm.PackageManager;import android.content.pm.PackageManager.NameNotFoundException;import android.os.Build;import android.os.Environment;import android.os.Process;import android.util.Log;public class CrashHandler implements UncaughtExceptionHandler {private static final String TAG = CrashHandler.class.getSimpleName();private static final boolean DEBUG = true;private static final String PATH = Environment.getExternalStorageDirectory().getPath() + "/CrashTest/log/";private static final String FILE_NAME = "crash";private static final String FILE_NAME_SUFFIX = ".trace";private static CrashHandler sInstance = new CrashHandler();private UncaughtExceptionHandler mDefaultCrashHandler;private Context mContext;private CrashHandler() {}public static CrashHandler getInstance() {return sInstance;}public void init(Context context) {mDefaultCrashHandler = Thread.getDefaultUncaughtExceptionHandler();Thread.setDefaultUncaughtExceptionHandler(this);mContext = context.getApplicationContext();}/** * thread 为出现未捕获异常的线程，ex为异常信息 */@Overridepublic void uncaughtException(Thread thread, Throwable ex) {try {// 到处异常信息到SD卡中dumpExceptionToSDCard(ex);// 这里可以上传异常信息到服务器，便于开发人员分析日志从而解决buguploadExceptionToServer();} catch (IOException e) {e.printStackTrace();}ex.printStackTrace();// 如果系统提供了默认的异常处理器，则交给系统结束程序，否则就由自己结束自己if (mDefaultCrashHandler != null) {mDefaultCrashHandler.uncaughtException(thread, ex);} else {Process.killProcess(Process.myPid());}}private void uploadExceptionToServer() {// TODO Auto-generated method stub}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("yyyyMMddHHmss").format(new Date(current));File file = new File(PATH + FILE_NAME + time + FILE_NAME_SUFFIX);try {PrintWriter pw = new PrintWriter(new BufferedWriter(new FileWriter(file)));pw.println(time);dumpPhoneInfo(pw);pw.println();ex.printStackTrace(pw);pw.close();} catch (Exception e) {Log.e(TAG, "dump crash info failed");}}private void dumpPhoneInfo(PrintWriter pw) throws NameNotFoundException {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);}}

CrashHandler在项目中的应用：

package com.example.crashhandler;import android.app.Application;public class MyApp extends Application{@Overridepublic void onCreate() {super.onCreate();CrashHandler crashHandler=CrashHandler.getInstance();crashHandler.init(this);}}

运行结果截图：

程序源码链接：

http://download.csdn.net/detail/yule12345/9820557