基于Android 9.0的应用启动流程分析

1 第一步我们加日志打印

package com.example.myapplication;

import android.app.Application;
import android.util.Log;

public class MyApplication extends Application {
    @Override
    public void onCreate() {
        super.onCreate();
        Log.d("XL_DBG","how application start :", new Throwable());
    }
}

package com.example.myapplication;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.util.Log;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        Log.d("XL_DBG","how startActivity work",new Throwable());
        setContentView(R.layout.activity_main);
    }
}

2 得到打印

2019-11-05 13:53:51.442 20175-20175/com.example.myapplication D/XL_DBG: how application start :
    java.lang.Throwable
        at com.example.myapplication.MyApplication.onCreate(MyApplication.java:10)
        at android.app.Instrumentation.callApplicationOnCreate(Instrumentation.java:1158)
        at android.app.ActivityThread.handleBindApplication(ActivityThread.java:6266)
        at android.app.ActivityThread.access$1200(ActivityThread.java:240)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1797)
        at android.os.Handler.dispatchMessage(Handler.java:106)
        at android.os.Looper.loop(Looper.java:214)
        at android.app.ActivityThread.main(ActivityThread.java:7094)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:494)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:975)
2019-11-05 13:53:51.645 20175-20175/com.example.myapplication D/XL_DBG: how startActivity work
    java.lang.Throwable
        at com.example.myapplication.MainActivity.onCreate(MainActivity.java:13)
        at android.app.Activity.performCreate(Activity.java:7340)
        at android.app.Activity.performCreate(Activity.java:7331)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1275)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3106)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3269)
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78)
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108)
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1960)
        at android.os.Handler.dispatchMessage(Handler.java:106)
        at android.os.Looper.loop(Looper.java:214)
        at android.app.ActivityThread.main(ActivityThread.java:7094)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:494)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:975)

其中Application启动中

handleBindApplication(AppBindData data)

比较重要，此处data 包含了Application启动的一系列参数，据此可以workaround。