Android 11 添加系统服务SystemService

添加自定义的systemservice，到时候就可以直接getSystemService这样使用了。

1.添加AIDL

在frameworks/base/core/java/android/os 下新建一个aidl文件

package android.os;

/**
 * @hide
 */
interface IMyTestService {
    void startTest( String text);
    void stopTest();
}

2.新建service

路径：frameworks/base/services/core/java/com/android/server

package com.android.server;

import android.util.Log;
import android.os.IMyTestService;

public class MyTestService extends IMyTestService.Stub {
    public MyTestService() {}

    @Override
    public void startTest(String text){
        Log.i("Test","MyTestService  startTest: "+text);
    }

    @Override
    public void stopTest(){
        Log.i("Test","MyTestService  stopTest");
    }
}

3.添加service到系统

路径： frameworks/base/services/java/com/android/server/SystemServer.java

private void startOtherServices(@NonNull TimingsTraceAndSlog t) {
        t.traceBegin("startOtherServices");

       //省略代码...

        try {
            final String SECONDARY_ZYGOTE_PRELOAD = "SecondaryZygotePreload";
            // We start the preload ~1s before the webview factory preparation, to
            // ensure that it completes before the 32 bit relro process is forked
            // from the zygote. In the event that it takes too long, the webview
            // RELRO process will block, but it will do so without holding any locks.
            mZygotePreload = SystemServerInitThreadPool.submit(() -> {
                try {
                    Slog.i(TAG, SECONDARY_ZYGOTE_PRELOAD);
                    TimingsTraceAndSlog traceLog = TimingsTraceAndSlog.newAsyncLog();
                    traceLog.traceBegin(SECONDARY_ZYGOTE_PRELOAD);
                    if (!Process.ZYGOTE_PROCESS.preloadDefault(Build.SUPPORTED_32_BIT_ABIS[0])) {
                        Slog.e(TAG, "Unable to preload default resources");
                    }
                    traceLog.traceEnd();
                } catch (Exception ex) {
                    Slog.e(TAG, "Exception preloading default resources", ex);
                }
            }, SECONDARY_ZYGOTE_PRELOAD);


            //添加
            ServiceManager.addService(Context.MY_TEST_SERVICE, new MyTestService());

4.新建manager

路径：frameworks/base/core/java/android/app  新建一个MyTestServiceManager

这边提供一些方法给别人用，当有地方调用了，它再去调用service中的方法。

package android.app;

import android.annotation.NonNull;
import android.content.Context;
import android.os.IMyTestService;
import android.os.RemoteException;


public class MyTestServiceManager {
    private IMyTestService mService;

    /**
     * @hide
     */
    public MyTestServiceManager(@NonNull Context mContext, @NonNull IMyTestService service) {
        mService = service;
    }

    /**
     * @hide
     */
    public void startTest(String text) {
        try {
            mService.startTest(text);
        } catch (RemoteException e) {
            e.printStackTrace();
        }
    }

    /**
     * @hide
     */
    public void stopTest() {
        try {
            mService.stopTest();
        } catch (RemoteException e) {
            e.printStackTrace();
        }
    }
}

5.注册这个manager

    static {
        //CHECKSTYLE:OFF IndentationCheck
        registerService(Context.ACCESSIBILITY_SERVICE, AccessibilityManager.class,
                new CachedServiceFetcher<AccessibilityManager>() {
            @Override
            public AccessibilityManager createService(ContextImpl ctx) {
                return AccessibilityManager.getInstance(ctx);
            }});

        //省略代码......

        

        registerService(Context.MY_TEST_SERVICE, MyTestServiceManager.class,
                new CachedServiceFetcher<MyTestServiceManager>() {
                    @Override
                    public MyTestServiceManager createService(ContextImpl ctx) {
                        IBinder b = ServiceManager.getService(Context.MY_TEST_SERVICE);
                        IMyTestService service = IMyTestService.Stub.asInterface(b);
                        return new MyTestServiceManager(ctx, service);
                    }
                });

到这里systemservice就添加好了，下面直接build。如果出现

就按照2来做。

注意所有函数都有加@hide

最后编译完，刷完image就可以直接使用我们自己添加的SystemService了。