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();
/**
* 获取CrashHandler实例，单例模式。
*
* @return 返回CrashHandler实例
*/
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);
}
}

import android.app.Application;
public class CrashApplication extends Application{
@Override
public void onCreate() {
super.onCreate();
CrashHandler.getInstance().init(this);
}
}

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/ 
<application
android:allowBackup="true"
android:name=".CrashApplication"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme"  
<activity
android:name="com.example.crashtestdemo.MainActivity"
android:label="@string/app_name"  
<intent-filter 
<action android:name="android.intent.action.MAIN" / 
<category android:name="android.intent.category.LAUNCHER" / 
</intent-filter 
</activity 
</application