一个错误日志记录工具类

package com.moxiu.downloader.util;/** * 当程序发生Uncaught异常的时候,有该类来接管程序,并记录错误日志 * Created by ZGP on 2017/7/25. */import android.annotation.SuppressLint;import android.content.Context;import android.content.pm.PackageInfo;import android.content.pm.PackageManager;import android.os.Build;import android.os.Looper;import android.os.SystemClock;import android.util.Log;import android.widget.Toast;import com.moxiu.downloader.Constants;import java.io.File;import java.io.FileOutputStream;import java.io.PrintWriter;import java.io.StringWriter;import java.io.Writer;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;@SuppressLint("SimpleDateFormat")public class CrashHandler implements Thread.UncaughtExceptionHandler {    public static String TAG = "MyCrash";    // 系统默认的UncaughtException处理类    private Thread.UncaughtExceptionHandler mDefaultHandler;    private static CrashHandler instance = new CrashHandler();    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");    /**     * 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 {            SystemClock.sleep(3000);            // 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;        try {            // 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,即将重启.",                            Toast.LENGTH_LONG).show();                    Looper.loop();                }            }.start();            // 收集设备参数信息            collectDeviceInfo(mContext);            // 保存日志文件            saveCrashInfoFile(ex);            SystemClock.sleep(3000);        } catch (Exception e) {            e.printStackTrace();        }        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 + "";                String versionCode = pi.versionCode + "";                infos.put("versionName", versionName);                infos.put("versionCode", versionCode);            }        } catch (PackageManager.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());            } 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     * @throws Exception     */    private String saveCrashInfoFile(Throwable ex) throws Exception {        StringBuffer sb = new StringBuffer();        try {            SimpleDateFormat sDateFormat = new SimpleDateFormat(                    "yyyy-MM-dd HH:mm:ss");            String date = sDateFormat.format(new java.util.Date());            sb.append("\r\n" + date + "\n");            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.flush();            printWriter.close();            String result = writer.toString();            sb.append(result);            String fileName = writeFile(sb.toString());            return fileName;        } catch (Exception e) {            Log.e(TAG, "an error occured while writing file...", e);            sb.append("an error occured while writing file...\r\n");            writeFile(sb.toString());        }        return null;    }    private String writeFile(String sb) throws Exception {        String time = formatter.format(new Date());        String fileName = "crash-" + time + ".log";        File dir = new File(Constants.MOXIU_FOLDER_ERROR_LOG);        if (!dir.exists())            dir.mkdirs();        FileOutputStream fos = new FileOutputStream(Constants.MOXIU_FOLDER_ERROR_LOG + fileName, true);        fos.write(sb.getBytes());        fos.flush();        fos.close();        return fileName;    }    public static void setTag(String tag) {        TAG = tag;    }} 

  注：

      1、使用时需要在application中初始化：

               CrashHandler.getInstance().init(this);

      2、此方法针对未被处理的异常，即没有被try catech包围的异常，对于ANR和try catch处理过的异常不会捕捉，不过可手动把Exception写入到日志中。