Android收集崩溃信息的原理

学习自

https://www.jianshu.com/p/91f494c7adf6

更推荐去集成sdk，本文侧重原理的解读

腾讯https://bugly.qq.com/v2/index

友盟http://www.umeng.com/

收集工具类

public class ExceptionCrashHandler implements Thread.UncaughtExceptionHandler {

    /***
     * 单例
     */

    public static ExceptionCrashHandler getInstance() {
        return SingletonHolder.INSTANCE;
    }

    static class SingletonHolder {
        static ExceptionCrashHandler INSTANCE = new ExceptionCrashHandler();
    }

    private ExceptionCrashHandler() {}

    /***
     * 初始化操作
     */

    private Application mContext;

    public void init(Application app) {
        this.mContext = app;
        Thread.currentThread().setUncaughtExceptionHandler(this);
    }

    /***
     * 拦截到crash
     */

    private static final String TAG = "xbh";

    @Override
    public void uncaughtException(Thread t, Throwable ex) {
        //获取信息（崩溃、手机、版本）并写入文件
        String crashFileName = saveInfoToSD(ex);

        //你去手机或者模拟器的这个目录下看就可以了
        //Log.e(TAG, "fileName --> " + crashFileName);

        //我下次登录需要上传崩溃信息到服务器里，所以我需要缓存crash文件的名称
        cacheCrashFile(crashFileName);
    }

    ///////////////////////////////////////////////////////////////////
    ////////////////////////下面的是util///////////////////////////////
    //////////////////////////////////////////////////////////////////

    /**
     * 缓存崩溃日志文件
     *
     * @param fileName
     */
    private void cacheCrashFile(String fileName) {
        SharedPreferences sp = mContext.getSharedPreferences("crash", Context.MODE_PRIVATE);
        sp.edit().putString("CRASH_FILE_NAME", fileName).apply();
    }


    /**
     * 获取崩溃文件名称
     *
     * @return
     */
    public File getCrashFile() {
        String crashFileName = mContext.getSharedPreferences("crash",
                Context.MODE_PRIVATE).getString("CRASH_FILE_NAME", "");
        return new File(crashFileName);
    }

    /**
     * 保存获取的 软件信息，设备信息和出错信息保存在SDcard中
     *
     * @param ex
     * @return
     */
    private String saveInfoToSD(Throwable ex) {
        String fileName = null;
        StringBuffer sb = new StringBuffer();

        for (Map.Entry, String> entry : obtainSimpleInfo(mContext)
                .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)) {
            File dir = new File(mContext.getFilesDir() + File.separator + "crash"
                    + File.separator);

            // 先删除之前的异常信息
            if (dir.exists()) {
                deleteDir(dir);
            }

            // 再从新创建文件夹
            if (!dir.exists()) {
                dir.mkdir();
            }
            try {
                fileName = dir.toString()
                        + File.separator
                        + getAssignTime("yyyy_MM_dd_HH_mm") + ".txt";
                FileOutputStream fos = new FileOutputStream(fileName);
                fos.write(sb.toString().getBytes());
                fos.flush();
                fos.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return fileName;
    }

    /**
     * 返回当前日期根据格式
     **/
    private String getAssignTime(String dateFormatStr) {
        DateFormat dataFormat = new SimpleDateFormat(dateFormatStr);
        long currentTime = System.currentTimeMillis();
        return dataFormat.format(currentTime);
    }


    /**
     * 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
     *
     * @return
     */
    private HashMap, String> obtainSimpleInfo(Context context) {
        HashMap, String> map = new HashMap<>();
        PackageManager mPackageManager = context.getPackageManager();
        PackageInfo mPackageInfo = null;
        try {
            mPackageInfo = mPackageManager.getPackageInfo(
                    context.getPackageName(), PackageManager.GET_ACTIVITIES);
        } catch (PackageManager.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);
        map.put("MOBLE_INFO", getMobileInfo());
        return map;
    }


    /**
     * Cell phone information
     *
     * @return
     */
    private static String getMobileInfo() {
        StringBuilder sb = new StringBuilder();
        try {
            Field[] fields = Build.class.getDeclaredFields();
            for (Field field : fields) {
                field.setAccessible(true);
                String name = field.getName();
                String value = field.get(null).toString();
                sb.append(name + "=" + value);
                sb.append("\n");
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return sb.toString();
    }


    /**
     * 获取系统未捕捉的错误信息
     *
     * @param throwable
     * @return
     */
    private String obtainExceptionInfo(Throwable throwable) {
        StringWriter stringWriter = new StringWriter();
        PrintWriter printWriter = new PrintWriter(stringWriter);
        throwable.printStackTrace(printWriter);
        printWriter.close();
        return stringWriter.toString();
    }


    /**
     * 递归删除目录下的所有文件及子目录下所有文件
     *
     * @param dir 将要删除的文件目录
     * @return boolean Returns "true" if all deletions were successful. If a
     * deletion fails, the method stops attempting to delete and returns
     * "false".
     */
    private boolean deleteDir(File dir) {
        if (dir.isDirectory()) {
            String[] children = dir.list();
            // 递归删除目录中的子目录下
            for (int i = 0; i < children.length; i++) {
                boolean success = deleteDir(new File(dir, children[i]));
                if (!success) {
                    return false;
                }
            }
        }
        // 目录此时为空，可以删除
        return true;
    }
}

Application中

public class App extends Application {
    @Override
    public void onCreate() {
        super.onCreate();
        ExceptionCrashHandler.getInstance().init(this);
    }
}

这样在下一次登录的时候 就可以进行一个崩溃信息的上传了

拿到这个file，然后上传这个file

File crashFile = ExceptionCrashHandler.getInstance().getCrashFile();

上传这里就不上传了 我们弄个crash的例子然后看看本地保存的crash信息

很nice，不过还是推荐sdk