在Android開發階段,總是不能保證沒有bug,當用戶遇到bug時直接閃退並不是很友好,而且對開發者並沒有什麼提示,不利於排除bug,所以我們需要一個異常處理,當app遇到bug時能將錯誤資訊生成檔案,並重啟app

完整的自定義程式碼

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 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;
import android.os.Looper;
import android.util.Log;
import android.widget.Toast;

import com.imedical.app.dhround.view.SplashActivity;

/**
 * UncaughtException處理類,當程式發生Uncaught異常的時候,有該類來接管程式,並記錄傳送錯誤報告.
 * 在繼承Application的類中輸入下述程式碼
 * 
 * @Override
 
 public void onCreate() { // TODO Auto-generated method stub
 *           super.onCreate(); MyCrashHandler crashHandler =
 *           MyCrashHandler.getInstance();
 *           crashHandler.init(getApplicationContext()); }
 */
public class MyCrashHandler implements UncaughtExceptionHandler {

    public static final String TAG = "MyCrashHandler";

// 系統預設的UncaughtException處理類
private Thread.UncaughtExceptionHandler mDefaultHandler;
// CrashHandler例項
private static MyCrashHandler myCrashHandler;
// 程式的Context物件
private Context mContext;
// 用來儲存裝置資訊和異常資訊
private Map<String, String> infos = new HashMap<String, String>();
// 錯誤資訊
private String errorMsg;
// 用於格式化日期,作為日誌檔名的一部分
private DateFormat formatter = new SimpleDateFormat("yyyy-MM-dd-HH-mm-ss");

/** 保證只有一個CrashHandler例項 */
private MyCrashHandler() {
}

/** 獲取CrashHandler例項 ,單例模式 */
public static MyCrashHandler getInstance() {
    if (myCrashHandler != null) {
        return myCrashHandler;
    } else {
        myCrashHandler = new MyCrashHandler();
        return myCrashHandler;
    }
}

/**
 * 初始化
 * 
 * @param context
 */
public void init(Context context) {
    mContext = context;
    // 獲取系統預設的UncaughtException處理器
    mDefaultHandler = Thread.getDefaultUncaughtExceptionHandler();
    // 設定該CrashHandler為程式的預設處理器
    Thread.setDefaultUncaughtExceptionHandler(this);
}

/**
 * 當UncaughtException發生時會轉入該函式來處理
 */
@Override
public void uncaughtException(Thread thread, Throwable ex) {
    if (!handleException(ex) && mDefaultHandler != null) {
        // 如果使用者沒有處理則讓系統預設的異常處理器來處理
        mDefaultHandler.uncaughtException(thread, ex);
    } else {
        try {
            Thread.sleep(3000);
        } catch (InterruptedException e) {
            Log.e(TAG, "error : ", e);
        }
        // //退出程式
        // android.os.Process.killProcess(android.os.Process.myPid());
        // System.exit(1);
        //

        // 重新啟動程式，註釋上面的退出程式
        Intent intent = new Intent(mContext, SplashActivity.class);
        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK
                | Intent.FLAG_ACTIVITY_CLEAR_TASK);
        mContext.startActivity(intent);
android.os.Process.killProcess(android.os.Process.myPid());
    }
}

/**
 * 自定義錯誤處理,收集錯誤資訊 傳送錯誤報告等操作均在此完成.
 * 
 * @param ex
 * @return true:如果處理了該異常資訊;否則返回false.
 */
private boolean handleException(final Throwable ex) {
    if (ex == null) {
        return false;
    }
    // 獲取錯誤資訊
     getErrorInfo(ex);
    // 使用Toast來顯示異常資訊
    new Thread() {
        @Override
        public void run() {
            Looper.prepare();
            Toast.makeText(mContext, "程式發生錯誤", Toast.LENGTH_SHORT).show();
            //使用郵箱傳送錯誤資訊
            // MailManager.sendmail(getErrorInfo(ex));
            Looper.loop();
        }
    }.start();
    // 收集裝置引數資訊
     collectDeviceInfo(mContext);
    // 儲存日誌檔案
     saveCrashInfo2File(ex);
    return true;
}

/**
 * 獲取錯誤的資訊
 */
private String getErrorInfo(Throwable arg1) {
    Writer writer = new StringWriter();
    PrintWriter pw = new PrintWriter(writer);
    arg1.printStackTrace(pw);
    pw.close();
    String error = writer.toString();
    Log.d(TAG, error);
    return error;
}

/**
 * 收集裝置引數資訊
 * 
 * @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);
    }
    // 反射獲取Build類的所有欄位
    Field[] fields = Build.class.getDeclaredFields();
    for (Field field : fields) {
        try {
            field.setAccessible(true);
            // 獲取靜態物件,各種裝置資訊
            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);
        }
    }
}

/**
 * 儲存錯誤資訊到檔案中
 * 
 * @param ex
 * @return 返回檔名稱,便於將檔案傳送到伺服器
 */
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 = "/sdcard/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;
    }
}

簡易處理

如果不需要裝置資訊或者其他比較複雜的處理,然後能友好的退出程式,並且告知使用者程式出錯,並重啟

public class MyApplication extends Application implements  
Thread.UncaughtExceptionHandler{
    @Override
    public void onCreate() {
        super.onCreate();
        Thread.setDefaultUncaughtExceptionHandler(this);
    }

    @Override  
    public void uncaughtException(Thread thread, Throwable ex) {  
        System.out.println("uncaughtException");  
        System.exit(0);  
        //重啟app
        Intent intent = new Intent(this, MainActivity);  
        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK |  
        Intent.FLAG_ACTIVITY_NEW_TASK);  
        startActivity(intent);  
    }  
}