Android 对全局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<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      
        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<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 = "/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：

<?xml version="1.0" encoding="utf-8"?>  
<manifest xmlns:android="http://schemas.android.com/apk/res/android"  
    package="com.forms.catchlog"  
    android:versionCode="1"  
    android:versionName="1.0" >  
    <uses-sdk android:minSdkVersion="8" />  
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>  
      
  
    <application  
        android:icon="@drawable/ic_launcher"  
        android:label="@string/app_name"   
        <span style="color:#ff0000;">android:name=".CrashApplication"></span>  
        <activity  
            android:label="@string/app_name"  
            android:name=".CatchExceptionLogActivity" >  
            <intent-filter >  
                <action android:name="android.intent.action.MAIN" />  
  
                <category android:name="android.intent.category.LAUNCHER" />  
            </intent-filter>  
        </activity>  
    </application>  
  
</manifest>