如何优雅的避免android(安卓)运行时崩溃

一.问题抛出

• android运行的时候难免会有一些空指针(NullPointerException)或者下标越界(IndexOutOfBoundsException),用户使用的过程操作某一个按钮的时候,就发生了崩溃.这时候可能还没有到他感兴趣的部分,程序就Crash掉了,因此导致了用户流失

• 在集成一些第三方库的时候,我们不能修改里面的实现(例如 Gson,FastJson,OkHttp,OkSocket,Glide)等,那么如果他们里面抛出异常如何解决,Glide加载图片之后填充图片时,如果Activity销毁就会造成崩溃,那么我们如何解决?

二.解决效果

预防崩溃演示效果图.gif

三.解决思路

• MainLooper一定要保证在崩溃的时候持续Loop
• 子线程发生崩溃,保证主线程Looper继续Loop
• 当绘制,测量,布局出现问题导致编舞者Crash时,应该及时处理(关闭当前异常的界面)
• 生命周期方法发生了异常,在ActivityThread里面hook其中的Instrumentation.进行代理.
• 对ActivityThread中的mH 变量添加Callback,对于不能再Instrumentation中处理的异常进行再次Catch.最大限度保证不崩溃.

四.成品Library

Github项目地址: https://github.com/xuuhaoo/DefenseCrash (欢迎Star)
集成方法:

• Please add the code into your project gradle file

allprojects {
    repositories {
        maven { url 'https://dl.bintray.com/xuuhaoo/maven/'}
    }
}

• Make sure you already done with above instructions in project gradle
  files, than you need put this into Module build.gradle file

dependencies {
    compile 'com.tonystark.android:defense_crash:2.0.0'
}

We provide you two options for choosing:

• Options 1: You should manually install the defense as following code

public class MyApp extends Application implements IExceptionHandler {
    @Override
    protected void attachBaseContext(Context base) {
        super.attachBaseContext(base);
    // step1: Initialize the lib.
        DefenseCrash.initialize();
    // setp2: Install the fire wall defense.
        DefenseCrash.install(this);
    }

    @Override
    public void onCaughtException(Thread thread, Throwable throwable, boolean isSafeMode) {
    // step3: Print the error when crashed during runtime.
        throwable.printStackTrace();
    // step4: Upload this throwable to your crash collection sdk.
    }

    @Override
    public void onEnterSafeMode() {
    // We enter the safe mode to keep the main looper loop after crashed.You’d better do nothing here,we just notify you.
    }

    @Override
    public void onMayBeBlackScreen(Throwable throwable) {
    // onLayout(),onMeasure() or onDraw() has breaks down,
    // it causes the drawing to be abnormal and the choreographer to break down.
    // We will notify you on this method,you’d better finish this activity or restart the application.
    }
}

• Options 2: To facilitate some users, we provide a DefenseCrashApplication super class for you to integrate,as following code

public class MyApp extends DefenseCrashApplication {
    @Override
    public void onCaughtException(Thread thread, Throwable throwable, boolean isSafeMode) {
    // step1: Print the error when crashed during runtime.
        throwable.printStackTrace();
    // step2: Upload this throwable to your crash collection sdk.
    }

    @Override
    public void onEnterSafeMode() {
    // We enter the safe mode to keep the main looper loop after crashed.You’d better do nothing here,we just notify you.
    }

    @Override
    public void onMayBeBlackScreen(Throwable throwable) {
    // onLayout(),onMeasure() or onDraw() has breaks down,
    // it causes the drawing to be abnormal and the choreographer to break down.
    // We will notify you on this method,you’d better finish this activity or restart the application.
    }
}

It is Done!