Android基础5

Binder功能简介

用途：Binder是一种进程间通信的机制。

特点：虚拟物理设备驱动，像人血管一样，穿梭在各个组件和进程之间，多进程通信，采用C/S架构。

参与角色：

Client进程：使用服务的进程需等待Server注册后，再向ServiceManager获取服务。

Server进程：提供服务的进程。需先向ServiceManager进行注册。

ServiceManager进程：管理注册过的服务。

Binder驱动：负责进程之间Binder通信的建立，Binder在进程之间的传递，Binder引用计数管理，数据包在进程之间的传递和交互等一系列底层支持。

优势

安全优势：传统的进程通信方式对于通信双方的身份并没有做出严格的验证，比如Socket通信的IP地址是客户端手动填入，很容易进行伪造。Binder机制从协议本身就支持对通信双方做身份校验，为每个APP分配UID，进程的UID是鉴别进程身份的重要标志，从而大大提高了安全性。

性能优势：

共享内存：数据拷贝0次，但复杂且容易产生安全问题

Binder：数据拷贝1次，兼顾简单已用和安全问题

传统Socket/管道/消息队列：数据拷贝2次。

代码例子并升级代码1

步骤：

​ 服务端：1、继承Service 2、编写AndroidManifest.xml

​ 客户端：1、编写Service的连接，并获取远程Ibinder 2、实现绑定Service代码 3、实现获取信息功能的代码

UseBinderService

MainActivity.java

package a.b.c.usebinderserver;

import android.content.Intent;
import android.os.Bundle;

import androidx.activity.EdgeToEdge;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.graphics.Insets;
import androidx.core.view.ViewCompat;
import androidx.core.view.WindowInsetsCompat;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        EdgeToEdge.enable(this);
        setContentView(R.layout.activity_main);
        ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main), (v, insets) -> {
            Insets systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars());
            v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom);
            return insets;
        });
    }
}

MyService.java

package a.b.c.usebinderserver;

import android.app.Service;
import android.content.Intent;
import android.os.Binder;
import android.os.IBinder;
import android.os.Parcel;
import android.os.RemoteException;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;

public class MyService extends Service
{

    public static final int REQUEST_CODE = 1000;
    private final Binder mBinder = new Binder()
    {
        @Override
        protected boolean onTransact(int code, @NonNull Parcel data, @Nullable Parcel reply, int flags) throws RemoteException
        {
            if(code == REQUEST_CODE)
            {
                String studentName = data.readString();
                int age = getStudentAge(studentName);
                if(reply !=null)
                {
                    reply.writeInt(age);
                }
                return true;
            }
            return super.onTransact(code, data, reply, flags);
        }
        public int getStudentAge(String name)
        {
            Student student = new Student();
            return student.getAge(name);
        }

    };

    @Nullable
    @Override
    public IBinder onBind(Intent intent)
    {
        return mBinder;
    }
}

Student.java

package a.b.c.usebinderserver;

import android.app.Service;
import android.content.Intent;
import android.os.Binder;
import android.os.IBinder;
import android.os.Parcel;
import android.os.RemoteException;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;

public class MyService extends Service
{

    public static final int REQUEST_CODE = 1000;
    private final Binder mBinder = new Binder()
    {
        @Override
        protected boolean onTransact(int code, @NonNull Parcel data, @Nullable Parcel reply, int flags) throws RemoteException
        {
            if(code == REQUEST_CODE)
            {
                String studentName = data.readString();
                int age = getStudentAge(studentName);
                if(reply !=null)
                {
                    reply.writeInt(age);
                }
                return true;
            }
            return super.onTransact(code, data, reply, flags);
        }
        public int getStudentAge(String name)
        {
            Student student = new Student();
            return student.getAge(name);
        }

    };

    @Nullable
    @Override
    public IBinder onBind(Intent intent)
    {
        return mBinder;
    }
}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">
    <uses-permission android:name="android.permission.INTERNET" />

    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.UseBinderServer"
        tools:targetApi="31">
        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <service android:name=".MyService"
            android:exported="true"
            android:enabled="true"
            android:process=":server">
            <intent-filter>
                <action android:name="android.intent.action.server.student"/>
            </intent-filter>
        </service>
    </application>

</manifest>

UseBinderClient

MainActivity.java

package a.b.c.usebinderclient;

import android.content.ComponentName;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Binder;
import android.os.Bundle;
import android.os.IBinder;
import android.os.Parcel;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

import androidx.activity.EdgeToEdge;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.graphics.Insets;
import androidx.core.view.ViewCompat;
import androidx.core.view.WindowInsetsCompat;

public class MainActivity extends AppCompatActivity
{
    TextView tv;
    Button btn_bindService,btn_searchAge;
    IBinder binder;
    public static final int REQUEST_CODE = 1000;

    private final ServiceConnection serviceConnection = new ServiceConnection()
    {
        @Override
        public void onServiceConnected(ComponentName componentName, IBinder iBinder)
        {
            binder = iBinder;

        }

        @Override
        public void onServiceDisconnected(ComponentName componentName)
        {
            binder = null;
        }
    };
    private void bindRemoteService()
    {
        String action = "android.intent.action.server.student";
        Intent intent = new Intent(action);
        intent.setPackage("a.b.c.usebinderserver");//这里认真点，不要加package
        boolean bt = this.bindService(intent, serviceConnection,BIND_AUTO_CREATE);
        Log.i("ttttt-client","bindRemoteService result:" + bt);
    }

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        EdgeToEdge.enable(this);
        setContentView(R.layout.activity_main);
        ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main), (v, insets) -> {
            Insets systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars());
            v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom);
            return insets;
        });
        tv = findViewById(R.id.tv_view);
        btn_bindService = findViewById(R.id.btn_bindService);
        btn_searchAge = findViewById(R.id.btn_searchAge);
        btn_bindService.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view)
            {
                bindRemoteService();
            }
        });
        btn_searchAge.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view)
            {
                Log.i("tttt-client","开始查询");
                getRemoteAge("zhangsan");
            }
        });
    }
    private void getRemoteAge(String name)
    {
        Parcel data = Parcel.obtain();
        Parcel reply = Parcel.obtain();
        data.writeString(name);
        try
        {
            if(binder == null)
            {
                return ;

            }
            binder.transact(REQUEST_CODE,data,reply,0);
            int age = reply.readInt();
            tv.setText("查询年龄结果："+age);
        }catch (Exception ee)
        {
            ee.printStackTrace();
            tv.setText(ee.toString());
        }

    }
}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">
    <uses-permission android:name="android.permission.INTERNET" />
    <queries>
        <package android:name="a.b.c.usebinderserver" />
    </queries>

    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.UseBinderClient"
        tools:targetApi="31">
        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

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

</manifest>

优化1：

​ 服务端：1、继承Service——优化创建Binder类实现传输和数据提供方法 2、编写AndroidManifest.xml

​ 客户端：1、编写Service的连接，并获取远程Ibinder——编写代理类管理Binder 2、实现绑定Service代码 3、实现获取信息功能代码——优化编写接口

UseBinderService

MainActivity.java

package a.b.c.usebinderserver;

import android.content.Intent;
import android.os.Bundle;

import androidx.activity.EdgeToEdge;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.graphics.Insets;
import androidx.core.view.ViewCompat;
import androidx.core.view.WindowInsetsCompat;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        EdgeToEdge.enable(this);
        setContentView(R.layout.activity_main);
        ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main), (v, insets) -> {
            Insets systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars());
            v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom);
            return insets;
        });
    }
}

MyService.java

package a.b.c.usebinderserver;

import android.os.Binder;
import android.os.Parcel;
import android.os.RemoteException;
import android.util.Log;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;

public class ServerBinder extends Binder implements IStudentInterface {
    public static final int REQUEST_CODE = 1000;

    @Override
    public int getStudentAge(String name) {
        Student student = new Student();
        return student.getAge(name);
    }

    @Override
    protected boolean onTransact(int code, @NonNull Parcel data, @Nullable Parcel reply, int flags) throws RemoteException {
        if (code == REQUEST_CODE){
            String studentName = data.readString();
            Log.i("ttttttt-service", "recv :"+studentName);
            int age = getStudentAge(studentName);
            Log.i("ttttttt-service", "return :"+age);
            if (reply != null)
                reply.writeInt(age);
            return true;
        }
        return super.onTransact(code, data, reply, flags);
    }
}

Student.java

package a.b.c.usebinderserver;
import java.util.HashMap;
import java.util.Map;
public class Student
{
    private Map<String,Integer> info = new HashMap<>();
    public Student ()
    {
        info.put("zhangsan",23);
        info.put("lisi",19);
        info.put("wangwu",20);
    }
    public int getAge(String name)
    {
        return info.get(name);
    }
    public void setAge(String name,int age)
    {
        info.put(name,age);
    }
}

ServerBinder.java

package a.b.c.usebinderserver;

import android.os.Binder;
import android.os.Parcel;
import android.os.RemoteException;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;

public class ServerBinder extends Binder implements IStudentInterface
{
    public static final int REQUEST_CODE = 1000;

    @Override
    public int getStudentAge(String name)
    {
        Student student = new Student();
        return student.getAge(name);
    }
        @Override
        protected boolean onTransact(int code, @NonNull Parcel data, @Nullable Parcel reply, int flags) throws RemoteException
        {
            if (code == REQUEST_CODE) {
                String studentName = data.readString();
                int age = getStudentAge(studentName);
                if (reply != null) {
                    reply.writeInt(age);
                }
                return true;
            }
            return super.onTransact(code, data, reply, flags);
        }

}

IStudentInterface.java

package a.b.c.usebinderserver;

public interface IStudentInterface
{
    //查询年龄接口
    int getStudentAge(String name);
}

UseBinderClient

MainActivity.java

package a.b.c.usebinderclient;

import android.content.ComponentName;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Binder;
import android.os.Bundle;
import android.os.IBinder;
import android.os.Parcel;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

import androidx.activity.EdgeToEdge;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.graphics.Insets;
import androidx.core.view.ViewCompat;
import androidx.core.view.WindowInsetsCompat;

public class MainActivity extends AppCompatActivity
{
    TextView tv;
    Button btn_bindService,btn_searchAge;
    IStudentInterface binder;


    private final ServiceConnection serviceConnection = new ServiceConnection()
    {
        @Override
        public void onServiceConnected(ComponentName componentName, IBinder iBinder)
        {
            binder = BinderProxy.asInerface(iBinder);
        }
        @Override
        public void onServiceDisconnected(ComponentName componentName)
        {
            binder = null;
        }
    };
    private void bindRemoteService()
    {
        String action = "android.intent.action.server.student";
        Intent intent = new Intent(action);
        intent.setPackage("a.b.c.usebinderserver");
        boolean bt = this.bindService(intent, serviceConnection,BIND_AUTO_CREATE);
        Log.i("ttttt-client","bindRemoteService result:" + bt);
    }

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        EdgeToEdge.enable(this);
        setContentView(R.layout.activity_main);
        ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main), (v, insets) -> {
            Insets systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars());
            v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom);
            return insets;
        });
        tv = findViewById(R.id.tv_view);
        btn_bindService = findViewById(R.id.btn_bindService);
        btn_searchAge = findViewById(R.id.btn_searchAge);
        btn_bindService.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view)
            {
                bindRemoteService();
            }
        });
        btn_searchAge.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view)
            {
                Log.i("tttt-client","开始查询");
                binder.getStudentAge("zhangsan");
            }
        });
    }

}

BinderProxy.java

package a.b.c.usebinderclient;

import android.os.IBinder;
import android.os.Parcel;

public class BinderProxy implements IStudentInterface
{
    public static final int REQUEST_CODE = 1000;
    private IBinder mRemoteBinder;
    public BinderProxy(IBinder mRemoteBinder)
    {
        this.mRemoteBinder = mRemoteBinder;
    }


    @Override
    public int getStudentAge(String name)
    {
        Parcel data = Parcel.obtain();
        Parcel reply = Parcel.obtain();
        data.writeString(name);
        int age = -1;
        try
        {
            if(mRemoteBinder== null)
            {
                return age;
            }
            mRemoteBinder.transact(REQUEST_CODE,data,reply,0);
            age = reply.readInt();
            return age;

        }catch (Exception ee)
        {
            ee.printStackTrace();
        }
        return age;
    }

    public static IStudentInterface asInerface(IBinder iBinder)
    {
        if(iBinder == null)
        {
            return null;
        }
        if(iBinder instanceof IStudentInterface)
        {
            return (IStudentInterface) iBinder;
        }
        else
        {
            return new BinderProxy(iBinder);
        }
    }
}

IStudetnInterface.java

package a.b.c.usebinderclient;

public interface IStudentInterface
{
    //查询年龄接口
    int getStudentAge(String name);
}

注意：Android11及以后的版本要在客户端加上服务端的包名

<queries>
    <package android:name="a.b.c.usebinderserver"
</queries>

在AndroidManifest.xml文件中，<queries>元素是用于声明应用需要的查询信息，这主要用于提高应用的安全性和隐私性，特别是在Android 11（API 级别 30）及更高版本中。<queries>元素允许应用声明它可以查询哪些其他应用的数据或组件，这有助于系统更好地管理应用的权限和可见性。