Android编程实现捕获程序异常退出时的错误log信息功能详解

import java.io.File;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;import java.io.PrintWriter;import java.io.StringWriter;import java.io.Writer;import java.lang.Thread.UncaughtExceptionHandler;import java.lang.reflect.Field;import java.text.SimpleDateFormat;import java.util.Date;import java.util.Locale;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.Looper;import android.util.Log;import android.widget.Toast;public class CrashHandler implements UncaughtExceptionHandler { private static final String TAG = CrashHandler.class.getSimpleName(); private static final String SINGLE_RETURN = "\n"; private static final String SINGLE_LINE = "--------------------------------"; private static CrashHandler mCrashHandler; private Context mContext; private UncaughtExceptionHandler mDefaultHandler; private StringBuffer mErrorLogBuffer = new StringBuffer();  public static CrashHandler getInstance() {  if (mCrashHandler == null) {   synchronized (CrashHandler.class) {    if (mCrashHandler == null) {     mCrashHandler = new CrashHandler();    }   }  }  return mCrashHandler; } public void init(Context context) {  mContext = context;  // 获取系统默认的uncaughtException处理类实例  mDefaultHandler = Thread.getDefaultUncaughtExceptionHandler();  // 设置成我们处理uncaughtException的类  Thread.setDefaultUncaughtExceptionHandler(this); } @Override public void uncaughtException(Thread thread, Throwable ex) {  Log.d(TAG, "uncaughtException:" + ex);  if (!handleException(ex) && mDefaultHandler != null) {   // 如果用户没有处理异常就由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) {    e.printStackTrace();   }   android.os.Process.killProcess(android.os.Process.myPid());  } } //处理异常事件 private boolean handleException(Throwable ex) {  if (ex == null) {   return false;  }  new Thread(new Runnable() {   @Override   public void run() {    Looper.prepare();    Toast.makeText(mContext, "很抱歉,程序出现异常,即将退出.", Toast.LENGTH_SHORT)      .show();    Looper.loop();   }  }).start();  // 收集设备参数信息  collectDeviceInfo(mContext);  // 收集错误日志  collectCrashInfo(ex);  // 保存错误日志  saveErrorLog();  //TODO: 这里可以加一个网络的请求，发送错误log给后台//  sendErrorLog();  return true; } //保存日志到/mnt/sdcard/AppLog/目录下，文件名已时间yyyy-MM-dd_hh-mm-ss.log的形式保存 private void saveErrorLog() {  if (Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState())) {   SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd hh-mm-ss", Locale.getDefault());   String format = sdf.format(new Date());   format += ".log";   String path = Environment.getExternalStorageDirectory().getPath()+"/AppLog/";   File file = new File(path);   if (!file.exists()){    file.mkdirs();   }   FileOutputStream fos = null;   try {    fos = new FileOutputStream(path+format);    fos.write(mErrorLogBuffer.toString().getBytes());    fos.flush();   } catch (FileNotFoundException e) {    e.printStackTrace();   } catch (IOException e) {    e.printStackTrace();   } finally {    if (fos != null) {     try {      fos.close();      fos = null;     } catch (IOException e) {      e.printStackTrace();     }    }   }  } } //收集错误信息 private void collectCrashInfo(Throwable ex) {  Writer info = new StringWriter();  PrintWriter printWriter = new PrintWriter(info);  ex.printStackTrace(printWriter);  Throwable cause = ex.getCause();  while (cause != null) {   cause.printStackTrace(printWriter);   cause = cause.getCause();  }  String result = info.toString();  printWriter.close();  //将错误信息加入mErrorLogBuffer中  append("", result);  mErrorLogBuffer.append(SINGLE_LINE + SINGLE_RETURN);  Log.d(TAG, "saveCrashInfo2File:" + mErrorLogBuffer.toString()); } //收集应用和设备信息 private void collectDeviceInfo(Context context) {  //每次使用前，清掉mErrorLogBuffer里的内容  mErrorLogBuffer.setLength(0);  mErrorLogBuffer.append(SINGLE_RETURN + SINGLE_LINE + SINGLE_RETURN);  //获取应用的信息  PackageManager pm = context.getPackageManager();  try {   PackageInfo pi = pm.getPackageInfo(context.getPackageName(),     PackageManager.GET_ACTIVITIES);   if (pi != null) {    append("versionCode", pi.versionCode);    append("versionName", pi.versionName);    append("packageName", pi.packageName);   }  } catch (NameNotFoundException e) {   e.printStackTrace();  }  mErrorLogBuffer.append(SINGLE_LINE + SINGLE_RETURN);  //获取设备的信息  Field[] fields = Build.class.getDeclaredFields();  getDeviceInfoByReflection(fields);  fields = Build.VERSION.class.getDeclaredFields();  getDeviceInfoByReflection(fields);  mErrorLogBuffer.append(SINGLE_LINE + SINGLE_RETURN); } //获取设备的信息通过反射方式 private void getDeviceInfoByReflection(Field[] fields) {  for (Field field : fields) {   try {    field.setAccessible(true);    append(field.getName(), field.get(null));   } catch (IllegalArgumentException e) {    e.printStackTrace();   } catch (IllegalAccessException e) {    e.printStackTrace();   }  } } //mErrorLogBuffer添加友好的log信息 private void append(String key, Object value) {  mErrorLogBuffer.append("" + key + ":" + value + SINGLE_RETURN); }}