使用UncaughtExceptionHandler保存全局异常

网上关于安卓开发过程中出现的异常捕抓问题已经讲得非常透彻了，现在为自己总结一下使用UncaughtExceptionHandler捕抓程序中没有处理的异常，不至于弹出：

那么这里的程序结构为：

代码如下：

public class CrashHandler implements UncaughtExceptionHandler {public static final String TAG = "CrashHandler";// 系统默认的UncaughtException处理类private Thread.UncaughtExceptionHandler mDefaultHandler;// CrashHandler实例private static CrashHandler INSTANCE = new CrashHandler();// 程序的Context对象private Context mContext;// 用来存储设备信息和异常信息private Map<String, String> infos = new HashMap<String, String>();// 用于格式化日期,作为日志文件名的一部分@SuppressLint("SimpleDateFormat")private DateFormat formatter = new SimpleDateFormat("yyyy-MM-dd-HH-mm-ss");/** 保证只有一个CrashHandler实例 */private CrashHandler() {}/** 获取CrashHandler实例 ,单例模式 */public static CrashHandler getInstance() {return INSTANCE;}/** * 初始化 *  * @param context */public void init(Context context) {mContext = context;// 获取系统默认的UncaughtException处理器mDefaultHandler = Thread.getDefaultUncaughtExceptionHandler();// 设置该CrashHandler为程序的默认处理器Thread.setDefaultUncaughtExceptionHandler(this);}/** * 当UncaughtException发生时会转入该函数来处理 */@Overridepublic void uncaughtException(Thread thread, Throwable ex) {Log.e("CrashHandler", "异常退出程序#0");// if (!handleException(ex) && mDefaultHandler != null) {if (!handleException(ex) && mDefaultHandler != null) {// 如果用户没有处理则让系统默认的异常处理器来处理mDefaultHandler.uncaughtException(thread, ex);} else {try {Thread.sleep(3000);} catch (InterruptedException e) {Log.e(TAG, "error : ", e);}for(Activity activity : CrashApplication.mylist){activity.finish();}CrashApplication.mylist.clear();Toast.makeText(mContext, "上传完成", Toast.LENGTH_SHORT).show();android.os.Process.killProcess(android.os.Process.myPid());System.exit(0);Looper.myLooper().quit();}}/** * 自定义错误处理,收集错误信息 发送错误报告等操作均在此完成. *  * @param ex * @return true:如果处理了该异常信息;否则返回false. */private boolean handleException(Throwable ex) {if (ex == null) {return false;}// 使用Toast来显示异常信息new Thread() {@Overridepublic void run() {Looper.prepare();Toast.makeText(mContext, "很抱歉,程序出现异常,即将退出.", Toast.LENGTH_LONG).show();Looper.loop();}}.start();// 收集设备参数信息collectDeviceInfo(mContext);// 保存日志文件saveCrashInfo2File(ex);return true;}/** * 收集设备参数信息 *  * @param ctx */public void collectDeviceInfo(Context ctx) {try {PackageManager pm = ctx.getPackageManager();PackageInfo pi = pm.getPackageInfo(ctx.getPackageName(),PackageManager.GET_ACTIVITIES);if (pi != null) {String versionName = pi.versionName == null ? "null": pi.versionName;String versionCode = pi.versionCode + "";infos.put("versionName", versionName);infos.put("versionCode", versionCode);}} catch (NameNotFoundException e) {Log.e(TAG, "an error occured when collect package info", e);}Field[] fields = Build.class.getDeclaredFields();for (Field field : fields) {try {field.setAccessible(true);infos.put(field.getName(), field.get(null).toString());Log.d(TAG, field.getName() + " : " + field.get(null));} catch (Exception e) {Log.e(TAG, "an error occured when collect crash info", e);}}}/** * 保存错误信息到文件中 *  * @param ex * @return 返回文件名称,便于将文件传送到服务器 */private String saveCrashInfo2File(Throwable ex) {StringBuffer sb = new StringBuffer();for (Map.Entry<String, String> entry : infos.entrySet()) {String key = entry.getKey();String value = entry.getValue();sb.append(key + "=" + value + "\n");}Writer 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();sb.append(result);try {long timestamp = System.currentTimeMillis();String time = formatter.format(new Date());String fileName = "crash-" + time + "-" + timestamp + ".log";if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {String path = Environment.getExternalStorageDirectory().getAbsolutePath()+"/crash/";File dir = new File(path);if (!dir.exists()) {dir.mkdirs();}FileOutputStream fos = new FileOutputStream(path + fileName);fos.write(sb.toString().getBytes());fos.close();}return fileName;} catch (Exception e) {Log.e(TAG, "an error occured while writing file...", e);}return null;}}

CrashApplication.java

public class CrashApplication extends Application {public static List<Activity> mylist = new ArrayList<Activity>();@Overridepublic void onCreate() {super.onCreate();CrashHandler crashHandler = CrashHandler.getInstance();crashHandler.init(getApplicationContext());}}

在MainActivity.java 中制造异常：

public class MainActivity extends Activity {String s;@Overrideprotected void onCreate(Bundle savedInstanceState) {CrashApplication.mylist.add(this);super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);System.out.println(s.equals("any string")); }}

这样就能在
mnt/sdcard/crash目录下看到异常信息：

信息内容为：

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.exceptionlog/com.example.exceptionlog.MainActivity}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
at android.app.ActivityThread.access$600(ActivityThread.java:141)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:5041)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at com.example.exceptionlog.MainActivity.onCreate(MainActivity.java:16)
at android.app.Activity.performCreate(Activity.java:5104)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
... 11 more
java.lang.NullPointerException
at com.example.exceptionlog.MainActivity.onCreate(MainActivity.java:16)
at android.app.Activity.performCreate(Activity.java:5104)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
at android.app.ActivityThread.access$600(ActivityThread.java:141)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:5041)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
at dalvik.system.NativeStart.main(Native Method)

这里不要忘记写入权限：

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

项目中正常使用的实际案例，并且保存设备信息：

import java.io.File;import java.io.FileOutputStream;import java.io.PrintWriter;import java.io.StringWriter;import java.lang.Thread.UncaughtExceptionHandler;import java.text.SimpleDateFormat;import java.util.Date;import java.util.HashMap;import java.util.Map;import java.util.TimeZone;import android.content.Context;import android.content.Intent;import android.content.pm.PackageInfo;import android.content.pm.PackageManager;import android.content.pm.PackageManager.NameNotFoundException;import android.os.Build;import android.os.Environment;/** * @author Admin * @Funtion 异常处理 */public class CrashHandler implements UncaughtExceptionHandler {private Thread.UncaughtExceptionHandler mDefaultHandler;private static CrashHandler instance ;private Context context;public static CrashHandler getInstance() {if(instance == null){instance = new CrashHandler();}return instance;}@Overridepublic void uncaughtException(Thread thread, Throwable ex) {savaInfoToSD(context, ex);if (ex == null && mDefaultHandler != null) {mDefaultHandler.uncaughtException(thread, ex);} else {Intent intent = new Intent(context, ExceptionActivity.class);intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP| Intent.FLAG_ACTIVITY_NEW_TASK);context.startActivity(intent);android.os.Process.killProcess(android.os.Process.myPid());System.exit(1);}}public void init(Context context) {this.context = context;if(mDefaultHandler == null){//mDefaultHandler = Thread.getDefaultUncaughtExceptionHandler();//Thread.setDefaultUncaughtExceptionHandler(this);}}/** * 保存获取的 软件信息，设备信息和出错信息保存在SDcard中 *  * @param context * @param ex * @return */private String savaInfoToSD(Context context, Throwable ex) {String fileName = null;StringBuffer sb = new StringBuffer();for (Map.Entry<String, String> entry : obtainSimpleInfo(context).entrySet()) {String key = entry.getKey();String value = entry.getValue();sb.append(key).append(" = ").append(value).append("\n");}sb.append(obtainExceptionInfo(ex));if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {String dirPath = Environment.getExternalStorageDirectory().getPath().toString()+ "/";File dir = new File(dirPath + "crashForDeveloper" + File.separator);if (!dir.exists()) {dir.mkdir();}File[] files = dir.listFiles();if(files.length > 20){// delete when record over 20for(int i=0;i<files.length;i++){files[i].delete();}}try {fileName = dir.toString() + File.separator+ paserTime(System.currentTimeMillis()) + ".log";FileOutputStream fos = new FileOutputStream(fileName);fos.write(sb.toString().getBytes());fos.flush();fos.close();} catch (Exception e) {e.printStackTrace();}}return fileName;}/** * 获取一些简单的信息,软件版本，手机版本，型号等信息存放在HashMap中 *  * @param context * @return */private HashMap<String, String> obtainSimpleInfo(Context context) {HashMap<String, String> map = new HashMap<String, String>();PackageManager mPackageManager = context.getPackageManager();PackageInfo mPackageInfo = null;try {mPackageInfo = mPackageManager.getPackageInfo(context.getPackageName(), PackageManager.GET_ACTIVITIES);} catch (NameNotFoundException e) {e.printStackTrace();}map.put("versionName", mPackageInfo.versionName);map.put("versionCode", "" + mPackageInfo.versionCode);map.put("MODEL", "" + Build.MODEL);map.put("SDK_INT", "" + Build.VERSION.SDK_INT);map.put("PRODUCT", "" + Build.PRODUCT);return map;}/** * 将毫秒数转换成yyyy-MM-dd-HH-mm-ss的格式 *  * @param milliseconds * @return */private String paserTime(long milliseconds) {System.setProperty("user.timezone", "Asia/Shanghai");TimeZone tz = TimeZone.getTimeZone("Asia/Shanghai");TimeZone.setDefault(tz);SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd-HH-mm-ss");String times = format.format(new Date(milliseconds));return times;}/** * 获取系统未捕捉的错误信息 *  * @param throwable * @return */private String obtainExceptionInfo(Throwable throwable) {StringWriter mStringWriter = new StringWriter();PrintWriter mPrintWriter = new PrintWriter(mStringWriter);throwable.printStackTrace(mPrintWriter);mPrintWriter.close();// Log.e(TAG, mStringWriter.toString());return mStringWriter.toString();}}