android抓取错误日志并上报到服务器

开发中，app线上版本经常会出现这样那样的问题，那我们如何知道出现了什么问题呢？并且能快速定位到错误并有效解决呢？这里就涉及到错误日志或叫崩溃日志了。一般情况下，我们都会继承友盟等第三方的错误日志，来抓到错误。但是抓错误原理是什么呢？接下来介绍一下，如何抓错误日志，并上报到服务器。
Android中提供了一个全局异常的捕获，方式如下：
1.定义一个类实现UncaughtExceptionHandler
2.在Application中初始化，Thread.setDefaultUncaughtExceptionHandler(handler);
3.将抓取到的错误保存到本地txt文件
4.上传到服务器
具体代码如下：
（1） 定义一个CrashHandler
public class CrashHandler implements UncaughtExceptionHandler {
private static CrashHandler myCrashHandler;
private CrashHandler() {
};
private Context context;
public final static String LOGPATH =Environment.getExternalStorageDirectory() + “/usershopping/crash.txt” ;
private UncaughtExceptionHandler defaultExceptionHandler;
public synchronized static CrashHandler getInstance() {
if (myCrashHandler == null) {
myCrashHandler = new CrashHandler();
}
return myCrashHandler;
}
public void init(Context context) {
this.context = context;
defaultExceptionHandler = Thread.getDefaultUncaughtExceptionHandler();
Thread.setDefaultUncaughtExceptionHandler(this);
}
public void uncaughtException(Thread thread, Throwable ex) {
if(!sdCardIsAvailable()){
ex.printStackTrace();
new Thread() {
@Override
public void run() {
Looper.prepare();
Toast.makeText(context, “异常退出”, Toast.LENGTH_LONG).show();
Looper.loop();
}
}.start();
new Thread() {
@Override
public void run() {
try {
Thread.sleep(4000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
android.os.Process.killProcess(android.os.Process.myPid());
}
}.start();
return;
}
//(3)将错误日志保存到本地txt文件
try {
// 在throwable的参数里面保存的有程序的异常信息
StringBuffer sb = new StringBuffer();
// 1.得到手机的版本信息 硬件信息
Field[] fields = Build.class.getDeclaredFields();
for (Field filed : fields) {
filed.setAccessible(true); // 暴力反射
String name = filed.getName();
String value = filed.get(null).toString();
sb.append(name);
sb.append(“=”);
sb.append(value);
sb.append(“\n”);
}

        // 2.得到当前程序的版本号
        PackageInfo info = context.getPackageManager().getPackageInfo(
                context.getPackageName(), 0);
        sb.append(info.versionName);
        sb.append("\n");
        // 3.得到当前程序的异常信息
        Writer writer = new StringWriter();
        PrintWriter printwriter = new PrintWriter(writer);

        ex.printStackTrace(printwriter);
        printwriter.flush();
        printwriter.close();

        sb.append(writer.toString());

        File ff = new File(LOGPATH);
        ff.createNewFile(); 
        FileWriter fw = new FileWriter(new File(LOGPATH));
        fw.write(sb.toString());

// System.out.println(sb);
fw.close();

    } catch (Exception e1) {
        e1.printStackTrace();
    }

    new Thread() {

        @Override
        public void run() {
            Looper.prepare();

            Toast.makeText(context, "异常退出", Toast.LENGTH_LONG).show();
            Looper.loop();

        }

    }.start();
    //出现异常后，退出app
    new Thread() {

        @Override
        public void run() {
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            android.os.Process.killProcess(android.os.Process.myPid());
        }

    }.start();

}

/**
 * 检测sdcard是否可用
 *
 * @return true为可用，否则为不可用
 */
public static boolean sdCardIsAvailable() {
    String status = Environment.getExternalStorageState();
    if (!status.equals(Environment.MEDIA_MOUNTED))
        return false;
    return true;
}

}
（2）在Application中开一个子线程，初始化
//抓错误日志
new Thread(){
@Override
public void run() {
//把异常处理的handler设置到主线程里面
CrashHandler ch = CrashHandler.getInstance();
ch.init(getApplicationContext());
}
}.start();
（4）上传到服务器
前几步，是只要发生崩溃，我们就会将崩溃日志保存到本地，然后强制退出app，接下来我们就可以在启动app的首个activity中，即闪屏页里，判断本地是否有错误日志txt，有就开启服务上传，上传成功后就要删除。这样做可以避免多个错误日志覆盖的问题。

//检查cash.txt是否存在 存在就开启服务  上传到服务器
    String path= Environment.getExternalStorageDirectory() + "/usershopping/crash.txt";
    final File cashFile=new File(path);
    if (cashFile.exists()){
        startService(new Intent(context, UploadCashService.class));
    }
    //这个服务是intentService  自动开启异步，执行结束后自动销毁

    public class UploadCashService extends IntentService {

        public UploadCashService(String name) {
            super(name);
        }
        public UploadCashService() {
            super("UploadCashService");
        }

        @Override
        public IBinder onBind(Intent intent) {
            return null;
        }

        @Override
        protected void onHandleIntent(@Nullable Intent intent) {

        }

        @SuppressWarnings("deprecation")
        @Override
        public int onStartCommand(Intent intent, int flags, int startId) {
            //开启上传
            upLoadCash(getApplicationContext());
            return super.onStartCommand(intent, flags, startId);

            }
        private void upLoadCash(final Context context) {
            String path= Environment.getExternalStorageDirectory() + "/usershopping/crash.txt";
            final File file=new File(path);
            final Map headers = new HashMap();
            final Map params = new HashMap();
            params.put("v1", "true");
            headers.put(App.TOKEN_NAME, SharedPreferencesUtils.getString(context, "TOKEN"));
            headers.put("ContentType", "multipart/form-data");
            headers.put("dcode",CommonUtil.getDeviceInfo(context));//手机唯一标识
            headers.put("brand", android.os.Build.BRAND);   //手机品牌
            headers.put("model", Build.MODEL);//手机型号
            headers.put("ver",android.os.Build.VERSION.RELEASE);//系统版本号
                        headers.put("appver", String.valueOf(CommonUtil.getVersion(context)));//app版本号
            headers.put("verName", String.valueOf(CommonUtil.getVersionName(context)));//app版本名
            headers.put("appname","CLIENT");
            PostFormBuilder post = OkHttpUtils.post()
                .url(new Constant(context).CASHUPLOAD)
                .params(params)
                .headers(headers);

            post.addFile("mFile" , System.currentTimeMillis() + Math.random() * 10 + ".txt",
                file);
            post.build().execute(new Callback