android 7.1.2 创建系统级服务

http://note.youdao.com/noteshare?id=0971ee06760cefc93d5bc2739ca9be01&sub=A90B6C65BD3F4BF48D44F14ECE2E47B4

总体流程：

1.创建接口

2.创建接口实现类

3.创建接口操作类

4.注册操作类

5.系统添加服务

6.解决权限问题。

备注：其实主要是1、2、3步骤。

 

 

具体步骤：

1.定义aidl文件。生成相应java文件。位置：/frameworks/basecore/java/android/os/ISelfManager.aidl

package android.os;

 

interface ISelfManager {

 

int selfAddNumber(int numberFirst, int numberSecond);

String selfAddString(String originalStr);

}

 

2.添加aidl文件到mk中，位置：frameworks/base/Android.mk已供编译：

LOCAL_SRC_FILES += \

core/java/android/accessibilityservice/IAccessibilityServiceConnection.aidl \

core/java/android/accessibilityservice/IAccessibilityServiceClient.aidl \

.....

core/java/android/os/ISelfManager.aidl \

3.编译生成接口。后面编译生成也可以。这里主要是逻辑上好理解，我先生成接口，在对接口进行实现和操作。

mmm frameworks/base

 

4.添加服务，已实现刚刚编译的接口，位置：frameworks/base/services/core/java/com/android/server

package com.android.server; import android.util.Log; import android.os.ISelfManager; public class SelfManagerService extends ISelfManager.Stub { private static final String TAG = "SelfManagerService"; public int selfAddNumber(int numberFirst, int numberSecond) { Log.d(TAG,"I WILL CALCULATE IT numberFirst is:"+numberFirst+" numberSecond is :"+numberSecond); return numberFirst + numberSecond; } public String selfAddString(String originalStr) { Log.d(TAG,"I will add a string to originalStr previous...."); return "previous lalala "+originalStr; } }

 

5.添加操作类：位置：/frameworks/base/core/java/android/app/SelfManager.java

package android.app; import android.util.Log; import android.os.ISelfManager; import android.content.Context; import android.os.RemoteException; public class SelfManager { private static String TAG = "SelfManager"; ISelfManager mSelfManager; public SelfManager(Context ctx,ISelfManager selfManager) { mSelfManager = selfManager; } public int selfAddNumber(int numberFirst, int numberSecond) throws RemoteException { Log.d(TAG,"SelfManager selfAddNumber ......... "); return mSelfManager.selfAddNumber(numberFirst,numberSecond); } public String selfAddString(String originalStr) throws RemoteException { Log.d(TAG,"SelfManager selfAddString ........."); return mSelfManager.selfAddString(originalStr); } }

 

6.注册类：位置：/frameworks/base/core/java/android/app/SystemServiceRegistry.java 类中

import android.os.ISelfManager; static { .... registerService("selfservice", SelfManager.class, new CachedServiceFetcher() { @Override public SelfManager createService(ContextImpl ctx) { IBinder b = ServiceManager.getService("selfservice"); ISelfManager service = ISelfManager.Stub.asInterface(b); return new SelfManager(ctx,service); }}); .... }

 

7.添加服务到系统：位置：/frameworks/base/services/java/com/android/server/SystemServer.java 的startOtherServices 方法中，注意：可能这个方法会有权限异常，最好加入try catch。

private void startOtherServices() { .... ServiceManager.addService("selfservice", new SelfManagerService()); .... }

 

备注：6.和 7 步骤中的“selfservice”一般在Context.java 中声明

 

8.权限问题：SELinux : avc: denied { add } for service ...错误

a.方法一：(记得替换相关img如果是模拟器替换掉ramdisk.img)

（1）添加服务类型：位置：/system/sepolicy/service.te

type self_service, system_api_service, system_server_service, service_manager_type;

（2）对服务添加权限：位置：/system/sepolicy/service_contexts

selfservice u:object_r:self_service:s0

(3)解决  SELinux : avc:  denied  { find } /system/sepolicy/untrusted_app.te

allow untrusted_app self_service:service_manager find;

b.手动关闭selinux：adb shell -> setenforce 0

 

9.编译：

（1）执行：make update-api -j4 完成之后会生成自己添加的服务的API 位置：/frameworks/base/api/current.txt

public class SelfManager { ctor public SelfManager(android.content.Context, android.os.ISelfManager); method public int selfAddNumber(int, int) throws android.os.RemoteException; method public java.lang.String selfAddString(java.lang.String) throws android.os.RemoteException; }

（2）make -j4

 

验证：

1.在android studio项目中引入，或创建SelfManager.java 注意包名为android.app。其实充当影子作用。

package android.app;

 

import android.os.RemoteException;

 

public class SelfManager {

 

public int selfAddNumber(int numberFirst, int numberSecond) throws RemoteException {

return 0;

}

 

public String selfAddString(String originalStr) throws RemoteException {

return "";

}

}

2.使用：

try {

SelfManager selfManager = (SelfManager) getSystemService("selfservice");

int addResult = selfManager.selfAddNumber(3,4);

Log.d("Servicehahatest","result is :"+addResult);

String strResult = selfManager.selfAddString("HELLO WORLD...");

Log.d("Servicehahatest","result is :"+strResult);

} catch(RemoteException e) {

Log.d("Servicehahatest","RemoteException happend .....e is :"+e.toString());

}

3.运行结果：

result is :7

等等其他日志