Android 捕获App意外退出错误的日志信息

1.创建获取日志信息的类AppLogHandler，该类的功能是捕获导致应用程序意外退出的错误的日志信息，这里写的是一个错误保存一个log文件，保存到SD卡对应的目录下。代码如下：

package com.ryan.test.crash;

import java.io.File;
import java.io.FileOutputStream;
import java.lang.Thread.UncaughtExceptionHandler;

import android.content.Context;
import android.os.Environment;
import android.os.Looper;

public class AppLogHandler implements UncaughtExceptionHandler {

	public static final boolean DEBUG = true;

	public static final String AGR_LOG_DIRECOTORY = "agrlog";

	private Thread.UncaughtExceptionHandler mDefaultHandler;

	private static AppLogHandler instance;

	private AppLogHandler() {
	}

	public static AppLogHandler getInstance() {
		if (instance == null) {
			instance = new AppLogHandler();
		}
		return instance;
	}

	public void init(Context context) {
		mDefaultHandler = Thread.getDefaultUncaughtExceptionHandler();
		Thread.setDefaultUncaughtExceptionHandler(this);
	}

	@Override
	public void uncaughtException(Thread thread, Throwable ex) {
		if (!handleException(ex) && mDefaultHandler != null) {
			mDefaultHandler.uncaughtException(thread, ex);
		} else {
			try {
				Thread.sleep(3000);
			} catch (Exception e) {
				e.printStackTrace();
			}
			android.os.Process.killProcess(android.os.Process.myPid());
			System.exit(10);
		}
	}

	private boolean handleException(final Throwable ex) {
		if (DEBUG) {
			if (ex == null) {
				return false;
			}
			final StackTraceElement[] stack = ex.getStackTrace();
			final String message = ex.getMessage();
			new Thread() {
				@Override
				public void run() {
					Looper.prepare();
					createLogDirectory();
					String fileName = AGR_LOG_DIRECOTORY + "/crash-" + System.currentTimeMillis() + ".log";
					File file = new File(
							Environment.getExternalStorageDirectory(), fileName);
					try {
						FileOutputStream fos = new FileOutputStream(file, true);
						fos.write(message.getBytes());
						for (int i = 0; i < stack.length; i++) {
							fos.write(stack[i].toString().getBytes());
						}
						fos.flush();
						fos.close();
					} catch (Exception e) {
					}
					Looper.loop();
				}
			}.start();
		}
		return false;
	}

	private void createLogDirectory() {
		File file = new File(Environment.getExternalStorageDirectory(), AGR_LOG_DIRECOTORY);
		try {
			if (!file.exists() || !file.isDirectory()) {
				file.mkdir();
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

}

2.为了读取Logcat的信息并保存到SD卡中，必须添加对应的权限：

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

3.新建MyApplication类继承自Application，在应用启动时开启对导致程序意外退出的错误的捕获：

import com.ryan.test.crash.AppLogHandler;

import android.app.Application;

public class MyApplication extends Application{

	@Override
	public void onCreate() {
		super.onCreate();
		AppLogHandler appLogHandler = AppLogHandler.getInstance();
		appLogHandler.init(getApplicationContext());
	}
}

4.为了使MyApplication生效，必须修改AndroidMenifest.xml文件：

 <application
        android:name="com.ryan.test.MyApplication"
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@android:style/Theme.NoTitleBar">
       <!-- 省略其他信息 -->
 </application>