Android 异常捕获存储

Android 异常

就 Java 语言来说，所有的异常都继承自 Throwable

• Thorwalbe
• • Error
• • Exception

其中,Error 是底层代码产生的，在前端开发时可以不管，但是开发时需要避免引起这类错误，比如图片过大

• Error
• • VirtualMachineException

而 Exception 是因为代码不规范导致的异常错误，常见的代表性异常：

- IOException
- - FileNoFoundException
- - EOFException

---

- RuntimeException
- - ClassCastException
- - ArrayIndexOutOfBoundsException

第三方捕获异常库

• 腾讯的 Bugly

    https://bugly.qq.com/
  

• 友盟的

异常捕获并存储类

• 实现抛出一个异常

• 实现捕获这个异常，并存储到本地文件

• 添加权限

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

• 修改 Application

  android:name = “.CrashApplication”

• CrashHandler.java

    package com.thorn.catchexceptiondemo;
    
    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.Environment;
    import android.os.Looper;
    import android.util.Log;
    import android.widget.Toast;
    
    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.sql.Date;
    import java.text.DateFormat;
    import java.text.SimpleDateFormat;
    import java.util.HashMap;
    import java.util.Map;
    
    public class CrashHandler implements Thread.UncaughtExceptionHandler {
    
        private final String TAG = "CrashHandler";
        private final String PATH = Environment.getExternalStorageDirectory().getPath() + "/crash_log/";
        // 系统默认的UncaughtException处理类
        private Thread.UncaughtExceptionHandler mDefaultHandler;
        // 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-SSS");
    
        private CrashHandler() {
        }
    
        /**
         * 获取CrashHandler实例 ,单例模式
         */
        @SuppressWarnings("WeakerAccess")
        protected static CrashHandler getCrashHandlerInstance() {
            return CrashInstanceHolder.CRASH_INSTANCE;
        }
    
        /**
         * 初始化
         *
         * @param context
         */
        @SuppressWarnings("WeakerAccess")
        protected 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 {
                try {
                    Thread.sleep(3000);
                } catch (InterruptedException e) {
                    Log.e(TAG, "error : ", e);
                }
                // 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;
            }
            // 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
            saveCrashInfoToFile(ex);
            return true;
        }
    
        /**
         * 收集设备参数信息
         *
         * @param ctx
         */
        private 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 (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());
                    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 void saveCrashInfoToFile(Throwable ex) {
    
            @SuppressWarnings("StringBufferMayBeStringBuilder") StringBuffer sb = new StringBuffer();
            for (Map.Entry<String, String> entry : infos.entrySet()) {
                String key = entry.getKey();
                String value = entry.getValue();
                sb.append(key).append("=").append(value).append("\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 {
                //以当前时间作为文件名
                final String FILE_NAME = formatter.format(new Date(System.currentTimeMillis())) + ".txt";
                if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
    
                    ;
                    File dir = new File(PATH);
                    if (!dir.exists()) {
                        //noinspection ResultOfMethodCallIgnored
                        boolean isMkdirs = dir.mkdirs();
                    }
                    FileOutputStream fos = new FileOutputStream(PATH + FILE_NAME);
                    fos.write(sb.toString().getBytes("UTF-8"));
                    fos.close();
                }
            } catch (Exception e) {
                Log.e(TAG, "an error occured while writing file...", e);
            }
        }
    
        private static final class CrashInstanceHolder {
            // CrashHandler实例
            @SuppressLint("StaticFieldLeak")
            private static final CrashHandler CRASH_INSTANCE = new CrashHandler();
        }
    }
  

• CrashApplication.java

    package com.thorn.catchexceptiondemo;
    
    import android.app.Application;
    
    public class CrashApplication extends Application {
    
        @Override
        public void onCreate() {
            super.onCreate();
            CrashHandler.getCrashHandlerInstance().init(this);
        }
    }
  

• MainActivity.java

    package com.thorn.catchexceptiondemo;
    
    import android.content.pm.PackageManager;
    import android.os.Bundle;
    import android.support.annotation.NonNull;
    import android.support.v4.app.ActivityCompat;
    import android.support.v7.app.AppCompatActivity;
    import android.util.Log;
    import android.view.View;
    import android.widget.TextView;
    
    public class MainActivity extends AppCompatActivity {
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            TextView mTvHello = findViewById(R.id.tv_hello);
    
            getPermission();//动态获取权限
    
            mTvHello.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    int a = 10 / 0;
                }
            });
        }
    
    
        private void getPermission() {
            ActivityCompat.requestPermissions(MainActivity.this, new String[]{android
                    .Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1);
        }
    
        @Override
        public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
            super.onRequestPermissionsResult(requestCode, permissions, grantResults);
            switch (requestCode) {
                case 1:
                    if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                        Log.e("jin","权限获取成功");
                        break;
                    }
                default:
                    break;
            }
        }
    }