安卓常用类

处理全局异常类

Android系统的“程序异常退出”，给应用的用户体验造成不良影响。为了捕获应用运行时异常并给出友好提示，便可继承UncaughtExceptionHandler类来处理。通过Thread.setDefaultUncaughtExceptionHandler()方法将异常处理类设置到线程上即可。

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;
        }
        Log.e("error",ex.toString());
        //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.e("error", 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();
            }
        }
    }
}