Android 对程序异常崩溃的捕捉
以下为异常捕捉处理代码：
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
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.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
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;
/**
* UncaughtException处理类,当程序发生Uncaught异常的时候,有该类来接管程序,并记录发送错误报告.
*
* 需要在Application中注册，为了要在程序启动器就监控整个程序。
*/
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;
//程序的Context对象
private Context mContext;
//用来存储设备信息和异常信息
private Map infos = new HashMap();
//用于格式化日期,作为日志文件名的一部分
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() {
if(instance == null)
instance = new CrashHandler();
return instance;
}
/**
* 初始化
*/
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
*/
@Override
public void uncaughtException(Thread thread, Throwable ex) {
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);
}
//退出程序
android.os.Process.killProcess(android.os.Process.myPid());
System.exit(1);
}
}
/**
* 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;
}
//收集设备参数信息
collectDeviceInfo(mContext);
//使用Toast来显示异常信息
new Thread() {
@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();
//保存日志文件
saveCatchInfo2File(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 saveCatchInfo2File(Throwable ex) {
StringBuffer sb = new StringBuffer();
for (Map.Entry 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 = "/mnt/sdcard/crash/";
File dir = new File(path);
if (!dir.exists()) {
dir.mkdirs();
}
FileOutputStream fos = new FileOutputStream(path + fileName);
fos.write(sb.toString().getBytes());
//发送给开发人员
sendCrashLog2PM(path+fileName);
fos.close();
}
return fileName;
} catch (Exception e) {
Log.e(TAG, "an error occured while writing file...", e);
}
return null;
}
/**
* 将捕获的导致崩溃的错误信息发送给开发人员
*
* 目前只将log日志保存在sdcard 和输出到LogCat中，并未发送给后台。
*/
private void sendCrashLog2PM(String fileName){
if(!new File(fileName).exists()){
Toast.makeText(mContext, "日志文件不存在！", Toast.LENGTH_SHORT).show();
return;
}
FileInputStream fis = null;
BufferedReader reader = null;
String s = null;
try {
fis = new FileInputStream(fileName);
reader = new BufferedReader(new InputStreamReader(fis, "GBK"));
while(true){
s = reader.readLine();
if(s == null) break;
//由于目前尚未确定以何种方式发送，所以先打出log日志。
Log.i("info", s.toString());
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}finally{ // 关闭流
try {
reader.close();
fis.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
} 针对异常的捕捉要进行全局监控整个项目，所以要将其在Application中注册(也就是初始化)：
import android.app.Application;
public class CrashApplication extends Application {
@Override
public void onCreate() {
super.onCreate();
CrashHandler catchHandler = CrashHandler.getInstance();
catchHandler.init(getApplicationContext());
}
}
现在模拟一个空指针异常：
import android.app.Activity;
import android.os.Bundle;
public class CatchExceptionLogActivity extends Activity {
/** Called when the activity is first created. */
private String s;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
System.out.println(s.equals("hello")); // s没有进行赋值，所以会出现NullPointException异常
}
}别忘了在配置文件中对Application进行注册：
android:name=".CrashApplication">