Android studio 全局捕获异常

1.安卓的异常分为运行异常和编译异常

2.异常捕获的原理
Thread.UncaughtExceptionHandler 是 Java 虚拟机处理由于未捕获异常而导致程序停止运行的接口当一个线程由于未捕获异常而停止运行的时候，Java 虚拟机就会通过 Thread的getUncaughtExceptionHandler() 方法拿到当前 Thread 的 Thread.UncaughtExceptionHandler，并调用该 Thread.UncaughtExceptionHandler 的
uncaughtException 方法。

3. 捕获异常后，如何优雅退出

     android.os.Process.killProcess(android.os.Process.myPid());
     System.exit(10);
   

4.bugly的使用和场景    

注册bugly，继承bugly，写个bug看log

布局文件只写个button 按钮

 <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Hello World!"
        android:onClick="click"
        />

在AndroidManifest.xml 清单文件中 注册

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

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme"
        android:name=".EHApplication">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

在MainActivity中的代码

package com.dingtao.exceptionhandlerdemo;

import android.Manifest;
import android.content.pm.PackageManager;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;

import java.util.List;

public class MainActivity extends AppCompatActivity {

    private List<String> list;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        if(ActivityCompat.checkSelfPermission(this,Manifest.permission.WRITE_EXTERNAL_STORAGE)
                ==PackageManager.PERMISSION_GRANTED){

        }else{

            ActivityCompat.requestPermissions(this,new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},100);

        }
    }

    public void click(View v){
        Log.i("dt",list.size()+"");
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        if (requestCode==100){
            if (grantResults[0]==PackageManager.PERMISSION_GRANTED){
                Log.i("dt",list.size()+"");
            }
        }
    }
}

在创建一个类

package com.dingtao.exceptionhandlerdemo;

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.text.TextUtils;
import android.widget.Toast;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.io.Writer;
import java.lang.reflect.Field;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;

/**
 * 作用:
 * 1.收集错误信息
 * 2.保存错误信息
 * Created by shenhua on 2017-08-22-0022.
 * Email shenhuanet@126.com
 */
public class CrashHandler implements Thread.UncaughtExceptionHandler {

    private static CrashHandler sInstance = null;
    private Thread.UncaughtExceptionHandler mDefaultHandler;
    private Context mContext;
    // 保存手机信息和异常信息
    private Map<String, String> mMessage = new HashMap<>();

    public static CrashHandler getInstance() {
        if (sInstance == null) {
            synchronized (CrashHandler.class) {
                if (sInstance == null) {
                    synchronized (CrashHandler.class) {
                        sInstance = new CrashHandler();
                    }
                }
            }
        }
        return sInstance;
    }

    private CrashHandler() {
    }

    /**
     * 初始化默认异常捕获
     *
     * @param context context
     */
    public void init(Context context) {
        mContext = context;
        // 获取默认异常处理器
        mDefaultHandler = Thread.getDefaultUncaughtExceptionHandler();
        // 将此类设为默认异常处理器
        Thread.setDefaultUncaughtExceptionHandler(this);
    }

    @Override
    public void uncaughtException(Thread t, Throwable e) {
        if (!handleException(e)) {
            // 未经过人为处理,则调用系统默认处理异常,弹出系统强制关闭的对话框
            if (mDefaultHandler != null) {
                mDefaultHandler.uncaughtException(t, e);
            }
        } else {
            // 已经人为处理,系统自己退出
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e1) {
                e1.printStackTrace();
            }
            System.exit(1);
        }
    }

    /**
     * 是否人为捕获异常
     *
     * @param e Throwable
     * @return true:已处理 false:未处理
     */
    private boolean handleException(Throwable e) {
        if (e == null) {// 异常是否为空
            return false;
        }
        new Thread() {// 在主线程中弹出提示
            @Override
            public void run() {
                Looper.prepare();
                Toast.makeText(mContext, "捕获到异常", Toast.LENGTH_SHORT).show();
                Looper.loop();
            }
        }.start();
        collectErrorMessages();
        saveErrorMessages(e);
        return false;
    }

    /**
     * 1.收集错误信息
     */
    private void collectErrorMessages() {
        PackageManager pm = mContext.getPackageManager();
        try {
            PackageInfo pi = pm.getPackageInfo(mContext.getPackageName(), PackageManager.GET_ACTIVITIES);
            if (pi != null) {
                String versionName = TextUtils.isEmpty(pi.versionName) ? "null" : pi.versionName;
                String versionCode = "" + pi.versionCode;
                mMessage.put("versionName", versionName);
                mMessage.put("versionCode", versionCode);
            }
            // 通过反射拿到错误信息
            Field[] fields = Build.class.getFields();
            if (fields != null && fields.length > 0) {
                for (Field field : fields) {
                    field.setAccessible(true);
                    try {
                        mMessage.put(field.getName(), field.get(null).toString());
                    } catch (IllegalAccessException e) {
                        e.printStackTrace();
                    }
                }
            }
        } catch (PackageManager.NameNotFoundException e) {
            e.printStackTrace();
        }
    }

    /**
     * 2.保存错误信息
     *
     * @param e Throwable
     */
    private void saveErrorMessages(Throwable e) {
        StringBuilder sb = new StringBuilder();
        for (Map.Entry<String, String> entry : mMessage.entrySet()) {
            String key = entry.getKey();
            String value = entry.getValue();
            sb.append(key).append("=").append(value).append("\n");
        }
        Writer writer = new StringWriter();
        PrintWriter pw = new PrintWriter(writer);
        e.printStackTrace(pw);
        pw.close();
        String result = writer.toString();
        sb.append(result);
        String time = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss", Locale.CHINA).format(new Date());
        String fileName = "crash-" + time + "-" + System.currentTimeMillis() + ".log";
        // 有无SD卡
        if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
            String path = Environment.getExternalStorageDirectory().getPath() + "/crash/";
            File dir = new File(path);
            if (!dir.exists()) dir.mkdirs();
            FileOutputStream fos = null;
            try {
                fos = new FileOutputStream(path + fileName);
                fos.write(sb.toString().getBytes());
            } catch (Exception e1) {
                e1.printStackTrace();
            } finally {
                if (fos != null) {
                    try {
                        fos.close();
                    } catch (IOException e1) {
                        e1.printStackTrace();
                    }
                }
            }
        }
    }
}

package com.example.exceptionhandlerdemo;

import android.app.Application;
import android.content.Context;

public class EHApplication extends Application {

    private static Context context;

    @Override
    public void onCreate() {
        super.onCreate();
        CrashHandler.getInstance().init(this);
        context = this;
    }

    public static Context getContext() {
        return context;
    }
}