使用UncaughtExceptionHandler保存全局异常(转)

From: https://blog.csdn.net/dreamintheworld/article/details/43669027
网上关于安卓开发过程中出现的异常捕抓问题已经讲得非常透彻了，现在为自己总结一下使用UncaughtExceptionHandler捕抓程序中没有处理的异常，不至于弹出：


那么这里的程序结构为：


代码如下：

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  
    @SuppressLint("SimpleDateFormat")  
    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() {  
        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) {  
        Log.e("CrashHandler", "异常退出程序#0");  
        // if (!handleException(ex) && mDefaultHandler != null) {  
        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);  
            }  
            for(Activity activity : CrashApplication.mylist){  
                activity.finish();  
            }  
            CrashApplication.mylist.clear();  
            Toast.makeText(mContext, "上传完成", Toast.LENGTH_SHORT).show();  
            android.os.Process.killProcess(android.os.Process.myPid());  
            System.exit(0);  
            Looper.myLooper().quit();  
        }  
    }  
  
    /** 
     * 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;  
        }  
        // 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_LONG)  
                        .show();  
                Looper.loop();  
            }  
        }.start();  
        // 收集设备参数信息  
        collectDeviceInfo(mContext);  
        // 保存日志文件  
        saveCrashInfo2File(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 saveCrashInfo2File(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 = Environment.getExternalStorageDirectory().getAbsolutePath()+"/crash/";  
                File dir = new File(path);  
                if (!dir.exists()) {  
                    dir.mkdirs();  
                }  
                FileOutputStream fos = new FileOutputStream(path + fileName);  
                fos.write(sb.toString().getBytes());  
                fos.close();  
            }  
            return fileName;  
        } catch (Exception e) {  
            Log.e(TAG, "an error occured while writing file...", e);  
        }  
        return null;  
    }  
}  


CrashApplication.java
[java] view plain copy
public class CrashApplication extends Application {  
    public static List<Activity> mylist = new ArrayList<Activity>();  
    @Override  
    public void onCreate() {  
        super.onCreate();  
        CrashHandler crashHandler = CrashHandler.getInstance();  
        crashHandler.init(getApplicationContext());  
    }  
}  


在MainActivity.java 中制造异常：
[java] view plain copy
public class MainActivity extends Activity {  
    String s;  
      
    @Override  
    protected void onCreate(Bundle savedInstanceState) {  
        CrashApplication.mylist.add(this);  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.activity_main);  
        System.out.println(s.equals("any string"));   
    }  
}  

这样就能在
mnt/sdcard/crash目录下看到异常信息：




信息内容为：

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.exceptionlog/com.example.exceptionlog.MainActivity}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
at android.app.ActivityThread.access$600(ActivityThread.java:141)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:5041)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at com.example.exceptionlog.MainActivity.onCreate(MainActivity.java:16)
at android.app.Activity.performCreate(Activity.java:5104)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
... 11 more
java.lang.NullPointerException
at com.example.exceptionlog.MainActivity.onCreate(MainActivity.java:16)
at android.app.Activity.performCreate(Activity.java:5104)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
at android.app.ActivityThread.access$600(ActivityThread.java:141)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:5041)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
at dalvik.system.NativeStart.main(Native Method)



这里不要忘记写入权限：

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

项目中正常使用的实际案例，并且保存设备信息：

import java.io.File;  
import java.io.FileOutputStream;  
import java.io.PrintWriter;  
import java.io.StringWriter;  
import java.lang.Thread.UncaughtExceptionHandler;  
import java.text.SimpleDateFormat;  
import java.util.Date;  
import java.util.HashMap;  
import java.util.Map;  
import java.util.TimeZone;  
  
import android.content.Context;  
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.Environment;  
  
/** 
 * @author Admin 
 * @Funtion 异常处理 
 */  
public class CrashHandler implements UncaughtExceptionHandler {  
  
    private Thread.UncaughtExceptionHandler mDefaultHandler;  
    private static CrashHandler instance ;  
    private Context context;  
  
    public static CrashHandler getInstance() {  
        if(instance == null){  
            instance = new CrashHandler();  
        }  
        return instance;  
    }  
      
  
    @Override  
    public void uncaughtException(Thread thread, Throwable ex) {  
        savaInfoToSD(context, ex);  
        if (ex == null && mDefaultHandler != null) {  
            mDefaultHandler.uncaughtException(thread, ex);  
        } else {  
  
            Intent intent = new Intent(context, ExceptionActivity.class);  
            intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP  
                    | Intent.FLAG_ACTIVITY_NEW_TASK);  
            context.startActivity(intent);  
  
            android.os.Process.killProcess(android.os.Process.myPid());  
            System.exit(1);  
        }  
    }  
  
    public void init(Context context) {  
        this.context = context;  
        if(mDefaultHandler == null){  
//          mDefaultHandler = Thread.getDefaultUncaughtExceptionHandler();  
//          Thread.setDefaultUncaughtExceptionHandler(this);  
        }  
          
    }  
  
    /** 
     * 保存获取的 软件信息，设备信息和出错信息保存在SDcard中 
     *  
     * @param context 
     * @param ex 
     * @return 
     */  
    private String savaInfoToSD(Context context, Throwable ex) {  
        String fileName = null;  
        StringBuffer sb = new StringBuffer();  
  
        for (Map.Entry<String, String> entry : obtainSimpleInfo(context)  
                .entrySet()) {  
            String key = entry.getKey();  
            String value = entry.getValue();  
            sb.append(key).append(" = ").append(value).append("\n");  
        }  
  
        sb.append(obtainExceptionInfo(ex));  
  
        if (Environment.getExternalStorageState().equals(  
                Environment.MEDIA_MOUNTED)) {  
            String dirPath = Environment.getExternalStorageDirectory()  
                    .getPath().toString()  
                    + "/";  
            File dir = new File(dirPath + "crashForDeveloper" + File.separator);  
            if (!dir.exists()) {  
                dir.mkdir();  
            }  
              
            File[] files = dir.listFiles();  
            if(files.length > 20){  
                // delete when record over 20  
                for(int i=0;i<files.length;i++){  
                    files[i].delete();  
                }  
            }  
            try {  
                fileName = dir.toString() + File.separator  
                        + paserTime(System.currentTimeMillis()) + ".log";  
                FileOutputStream fos = new FileOutputStream(fileName);  
                fos.write(sb.toString().getBytes());  
                fos.flush();  
                fos.close();  
            } catch (Exception e) {  
                e.printStackTrace();  
            }  
  
        }  
  
        return fileName;  
    }  
  
    /** 
     * 获取一些简单的信息,软件版本，手机版本，型号等信息存放在HashMap中 
     *  
     * @param context 
     * @return 
     */  
    private HashMap<String, String> obtainSimpleInfo(Context context) {  
        HashMap<String, String> map = new HashMap<String, String>();  
        PackageManager mPackageManager = context.getPackageManager();  
        PackageInfo mPackageInfo = null;  
        try {  
            mPackageInfo = mPackageManager.getPackageInfo(  
                    context.getPackageName(), PackageManager.GET_ACTIVITIES);  
        } catch (NameNotFoundException e) {  
            e.printStackTrace();  
        }  
  
        map.put("versionName", mPackageInfo.versionName);  
        map.put("versionCode", "" + mPackageInfo.versionCode);  
  
        map.put("MODEL", "" + Build.MODEL);  
        map.put("SDK_INT", "" + Build.VERSION.SDK_INT);  
        map.put("PRODUCT", "" + Build.PRODUCT);  
  
        return map;  
    }  
  
    /** 
     * 将毫秒数转换成yyyy-MM-dd-HH-mm-ss的格式 
     *  
     * @param milliseconds 
     * @return 
     */  
    private String paserTime(long milliseconds) {  
        System.setProperty("user.timezone", "Asia/Shanghai");  
        TimeZone tz = TimeZone.getTimeZone("Asia/Shanghai");  
        TimeZone.setDefault(tz);  
        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd-HH-mm-ss");  
        String times = format.format(new Date(milliseconds));  
  
        return times;  
    }  
  
    /** 
     * 获取系统未捕捉的错误信息 
     *  
     * @param throwable 
     * @return 
     */  
    private String obtainExceptionInfo(Throwable throwable) {  
        StringWriter mStringWriter = new StringWriter();  
        PrintWriter mPrintWriter = new PrintWriter(mStringWriter);  
        throwable.printStackTrace(mPrintWriter);  
        mPrintWriter.close();  
        // Log.e(TAG, mStringWriter.toString());  
        return mStringWriter.toString();  
    }  
}