Android开发之处理崩溃异常

众所周知，android的设备千差万别，难免会发生崩溃异常等现象，这个时候就需要捕获哪些崩溃异常了，也就是捕获崩溃异常的相关信息，并记录下来，这样一来方便开发人员和测试人员的分析与调试。

1.首先我们得创建一个处理崩溃异常的类，暂且命名为：CrashHandler吧。实现如下：

import java.io.File;
import java.io.FileOutputStream;
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 java.util.TimeZone;



import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.DialogInterface.OnClickListener;
import android.content.Intent;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.content.pm.PackageManager.NameNotFoundException;
import android.os.Build;
import android.os.Looper;
import android.sax.StartElementListener;
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到log文件中.
 *
 * @author caizhiming 
 */
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 = new CrashHandler();
    // 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 SimpleDateFormat formatter;

    /**
     * 保证只有一个CrashHandler实例
     */
    private CrashHandler() {
    }

    /**
     * 获取CrashHandler实例 ,单例模式
     */
    public static CrashHandler getInstance() {
        return INSTANCE;
    }

    /**
     * 初始化
     *
     * @param context
     */
    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 {
            // 退出程序
            try {
                Thread.sleep(300);
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            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(final Throwable ex) {
        if (ex == null) {
            return false;
        }

//        Intent showcrashDLg = new Intent(mContext,CrashActivity.class);
//        mContext.startActivity(showcrashDLg);

        ex.printStackTrace();
        // 使用Toast来显示异常信息


        // 收集设备参数信息
        collectDeviceInfo(mContext);


        // 保存日志文件
        saveCrashInfoToFile(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 错误崩溃信息写到log文件中
     */
    private void saveCrashInfoToFile(Throwable ex) {
        StringBuffer sb = new StringBuffer();
        sb.append("==============================Crash happened at Time："
                + CommonUtils.getCurTime()
                + "==============================
");
        for (Map.Entry<String, String> entry : infos.entrySet()) {
            String key = entry.getKey();
            String value = entry.getValue();
            sb.append(key + "=" + value + "
");
        }


        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 {
            LogCore.addLog(sb.toString());

        } catch (Exception e) {
            Log.e(TAG, "an error occured while writing file...", e);
        }
        Analyse.uplodcrash(sb.toString());

    }

    /**
     * 用Dialog显示错误信息
     *
     * @param ex
     * @return 用Dialog显示错误信息
     */
    private void showCrashInfoDialog(Throwable ex) {

        StringBuffer sb = new StringBuffer();

        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 {
            // DlgUtils.ShowDialog(mContext,"程序崩溃了");
            // LogCore.d(mContext,sb.toString());
            AlertDialog.Builder builder = new AlertDialog.Builder(mContext);
            builder.setTitle("程序崩溃啦~");
            builder.setMessage(sb.toString());
            builder.setPositiveButton("我知道了", new OnClickListener() {

                @Override
                public void onClick(DialogInterface dialog, int which) {
                    // TODO Auto-generated method stub
                    android.os.Process.killProcess(android.os.Process.myPid());
                    System.exit(1);
                }
            });
//            builder.create().show();
        } catch (Exception e) {
            Log.e(TAG, "an error occured while writing file...", e);
        }
    }

}

2.完成这个CrashHandler后，我们需要在一个Application环境中让其运行，为此，我们继承android.app.Application，添加自己的代码，CrashApplication.java代码如下：

package com.czm.crash;  
  
import android.app.Application;  
  
public class CrashApplication extends Application {  
    @Override  
    public void onCreate() {  
        super.onCreate();  
        CrashHandler crashHandler = CrashHandler.getInstance();  
        crashHandler.init(getApplicationContext());  
    }  
}  

3.除此之外，最后，为了让上面的CrashApplication取代android.app.Application的地位，在我们的代码中生效，我们需要修改AndroidManifest.xml：

<application android:name=".CrashApplication" ...>  
</application>