Android开发之全局异常捕获

[转载请注明出处]本文出自付小华的博客 http://blog.csdn.net/klxh2009

今晨谷歌正式发布Android 8.0，新版本的Android O系统对API做出了各种变更，其中大部分会影响到很多应用，其中包括记录未捕获的异常.
如果某个应用安装的Thread.UncaughtExceptionHandler未移交给默认的Thread.UncaughtExceptionHandler，则当出现未捕获的异常时，系统不会终止应用，即不会出现系统默认的“抱歉，xxx应用已停止运行”.因此，我们就可以对应用的异常进行全局捕获，从而将异常保存下来，方便以后分析问题.

接下来查看源码:

通过源码可以知道:
Thread.UncaughtExceptionHandler是一个当线程由于未捕获的异常突然终止而调用处理程序的接口.
当线程由于未捕获的异常即将终止时，Java虚拟机将使用它来查询其UncaughtExceptionHandler的线程Thread.getUncaughtExceptionHandler()，并将调用处理程序的 uncaughtException方法，将线程和异常作为参数传递。如果一个线程没有显示它的UncaughtExceptionHandler，那么它的ThreadGroup对象充当它的 UncaughtExceptionHandler。如果ThreadGroup对象没有处理异常的特殊要求，它可以将调用转发到默认的未捕获的异常处理程序。

因此我们可以自定一个类去实现该接口，该类主要用于收集错误信息和保存错误信息.

详细代码

/*** 作用:* 1.收集错误信息* 2.保存错误信息* Created by shenhua on 2017-08-22-0022.* Email shenhuanet@126.com*/
public class CrashHandler implements Thread.UncaughtExceptionHandler {private static CrashHandler sInstance = null;private Thread.UncaughtExceptionHandler mDefaultHandler;private Context mContext;// 保存手机信息和异常信息private Map<String, String> mMessage = new HashMap<>();public static CrashHandler getInstance() {if (sInstance == null) {synchronized (CrashHandler.class) {if (sInstance == null) {synchronized (CrashHandler.class) {sInstance = new CrashHandler();}}}}return sInstance;}private CrashHandler() {}/*** 初始化默认异常捕获** @param context context*/public void init(Context context) {mContext = context;// 获取默认异常处理器mDefaultHandler = Thread.getDefaultUncaughtExceptionHandler();// 将此类设为默认异常处理器Thread.setDefaultUncaughtExceptionHandler(this);}@Overridepublic void uncaughtException(Thread t, Throwable e) {if (!handleException(e)) {// 未经过人为处理,则调用系统默认处理异常,弹出系统强制关闭的对话框if (mDefaultHandler != null) {mDefaultHandler.uncaughtException(t, e);}} else {// 已经人为处理,系统自己退出try {Thread.sleep(1000);} catch (InterruptedException e1) {e1.printStackTrace();}Process.killProcess(Process.myPid());System.exit(1);}}/*** 是否人为捕获异常** @param e Throwable* @return true:已处理 false:未处理*/private boolean handleException(Throwable e) {if (e == null) {// 异常是否为空return false;}new Thread() {// 在主线程中弹出提示@Overridepublic void run() {Looper.prepare();Toast.makeText(mContext, "捕获到异常", Toast.LENGTH_SHORT).show();Looper.loop();}}.start();collectErrorMessages();saveErrorMessages(e);return false;}/*** 1.收集错误信息*/private void collectErrorMessages() {PackageManager pm = mContext.getPackageManager();try {PackageInfo pi = pm.getPackageInfo(mContext.getPackageName(), PackageManager.GET_ACTIVITIES);if (pi != null) {String versionName = TextUtils.isEmpty(pi.versionName) ? "null" : pi.versionName;String versionCode = "" + pi.versionCode;mMessage.put("versionName", versionName);mMessage.put("versionCode", versionCode);}// 通过反射拿到错误信息Field[] fields = Build.class.getFields();if (fields != null && fields.length > 0) {for (Field field : fields) {field.setAccessible(true);try {mMessage.put(field.getName(), field.get(null).toString());} catch (IllegalAccessException e) {e.printStackTrace();}}}} catch (PackageManager.NameNotFoundException e) {e.printStackTrace();}}/*** 2.保存错误信息** @param e Throwable*/private void saveErrorMessages(Throwable e) {StringBuilder sb = new StringBuilder();for (Map.Entry<String, String> entry : mMessage.entrySet()) {String key = entry.getKey();String value = entry.getValue();sb.append(key).append("=").append(value).append("\n");}Writer writer = new StringWriter();PrintWriter pw = new PrintWriter(writer);e.printStackTrace(pw);Throwable cause = e.getCause();// 循环取出Causewhile (cause != null) {cause.printStackTrace(pw);cause = e.getCause();}pw.close();String result = writer.toString();sb.append(result);String time = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss", Locale.CHINA).format(new Date());String fileName = "crash-" + time + "-" + System.currentTimeMillis() + ".log";// 有无SD卡if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {String path = Environment.getExternalStorageDirectory().getPath() + "crash/";File dir = new File(path);if (!dir.exists()) dir.mkdirs();FileOutputStream fos = null;try {fos = new FileOutputStream(path + fileName);fos.write(sb.toString().getBytes());} catch (Exception e1) {e1.printStackTrace();} finally {if (fos != null) {try {fos.close();} catch (IOException e1) {e1.printStackTrace();}}}}}
}

CrashHandler注释比较清晰,应该可以看得明白.

使用

public class App extends Application {@Overridepublic void onCreate() {super.onCreate();CrashHandler.getInstance().init(this);}
}

注意事项

6.0运行时权限请求
Application全局设定