[Android]使用AIDL进行进程间通信

本文介绍IPC通信机制中的AIDL方式的实现。

Binder是Android中的一个类，它是Android中虚拟的一个硬件设备，驱动是/dev/binder。我们可以理解为Android中专有的用于进程间通信的设备。

下面实现一个基于AIDL进程间通信的实例。

代码结构如下：

其中：
MainActivity.java是我们的测试界面；
User.java是user类；
User.aidl和IUserManager.aidl是按照AIDL规范定义的接口；
IBinderService.java是service类。

代码实现的功能就是要实现一个用户的注册和登陆功能。
这里直接贴出代码了：

//MainActivity.java
package string.pub;

import java.util.Date;

import string.pub.binder.IUserManager;
import string.pub.binder.User;
import android.app.Activity;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Bundle;
import android.os.IBinder;
import android.os.RemoteException;
import android.view.View;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.TextView;

public class MainActivity extends Activity {
    TextView tv;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        LinearLayout ll=new LinearLayout(this);
         tv=new TextView(this);
        final StringBuilder sb=new StringBuilder();
        Button addUser=new Button(this);
        addUser.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                User temp=new User();
                temp.userName="U123";
                temp.pwd="123";
                temp.sex=1;
                temp.name="temp"+(new Date()).getSeconds();
        try {
                if(userBinder.register(temp)){
                tv.append(temp.toString()+"add user success\n");
            }
            } catch (RemoteException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    });
    addUser.setText("addUser");
    Button loginUser=new Button(this);
    loginUser.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                User temp=new User();
                temp.userName="U123";
                try {
                    if(userBinder.login(temp)){
                        tv.append(temp.toString()+"login user success\n");
                    }
                } catch (RemoteException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        });
        loginUser.setText("loginUser");

        ll.addView(loginUser);
        ll.addView(addUser);
        ll.addView(tv);
        setContentView(ll);


    bindService(new Intent("string.pub.action.Binder"), conn, Context.BIND_AUTO_CREATE);
    }
    IUserManager userBinder;
    ServiceConnection conn=new ServiceConnection() {

        @Override
        public void onServiceDisconnected(ComponentName name) {
            // TODO Auto-generated method stub

        }

        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            // TODO Auto-generated method stub
            userBinder=IUserManager.Stub.asInterface(service);
        }
    };
}

//User.java
package string.pub.binder;

import android.os.Parcel;
import android.os.Parcelable;

public class User implements Parcelable{
    public String userName;
    public String pwd;
    public int sex;
    public String name;
    @Override
    public int describeContents() {
        // TODO Auto-generated method stub
        return 0;
    }
    @Override
    public void writeToParcel(Parcel dest, int flags) {
        // TODO Auto-generated method stub
        dest.writeString(userName);
        dest.writeString(pwd);
        dest.writeInt(sex);
        dest.writeString(name);
    }

public static final Parcelable.Creator<User> CREATOR=new Creator<User>() {

        @Override
        public User[] newArray(int size) {
            // TODO Auto-generated method stub
            return new User[size];
        }

        @Override
        public User createFromParcel(Parcel source) {
            // TODO Auto-generated method stub
            User result=new User();
            result.userName=source.readString();
            result.pwd=source.readString();
            result.sex=source.readInt();
            result.name=source.readString();
            return result;
        }
    };
    @Override
    public String toString() {
        return "UserBean [userName=" + userName + ", pwd=" + pwd + ", sex="
                + sex + ", name=" + name + "]";
    }

}

    // IUserManager.aidl
    package string.pub.binder;
    import string.pub.binder.User;
    interface IUserManager{
     boolean register(in User u);
     boolean login(in User u);
     boolean modified(in User u);
    }

//User.aidl
package string.pub.binder;
parcelable User; 

    //IBinderService.java
    package string.pub.service;

    import java.util.ArrayList;

    import string.pub.binder.IUserManager;
    import string.pub.binder.User;
    import android.app.Service;
    import android.content.Intent;
    import android.os.IBinder;
    import android.os.RemoteException;

    public class IBinderService extends Service {
        ArrayList<User> listUser=new ArrayList<User>();
        @Override
        public IBinder onBind(Intent intent) {
            // TODO Auto-generated method stub
            return userBinder;
        }

        IBinder userBinder=new IUserManager.Stub(){

            @Override
            public boolean register(User u) throws RemoteException {
                // TODO Auto-generated method stub
                return listUser.add(u);
            }

            @Override
            public boolean login(User u) throws RemoteException {
                // TODO Auto-generated method stub
                for(int i=0;i<listUser.size();i++){
                    if((listUser.get(i)).userName.equals(u.userName)){
                        return true;
                    }
                }
                return false;
            }

            @Override
            public boolean modified(User u) throws RemoteException {
                // TODO Auto-generated method stub
                for(int i=0;i<listUser.size();i++){
                    User temp=new User();
                    if((temp=listUser.get(i)).userName.equals(u.userName)){
                        listUser.remove(temp);
                        listUser.add(u);
                        return true;
                    }
                }
                return false;
            }

        };

    }

    //AndroidManifest.xml
    <?xml version="1.0" encoding="utf-8"?>
    <manifest xmlns:android="http://schemas.android.com/apk/res/android"
        package="string.pub"
        android:versionCode="1"
        android:versionName="1.0" >

        <uses-sdk
            android:minSdkVersion="14"
            android:targetSdkVersion="21" />

        <application
            android:allowBackup="true"
            android:icon="@drawable/ic_launcher"
            android:label="@string/app_name"
            android:theme="@style/AppTheme" >
            <activity
                android:name=".MainActivity"
                android:label="@string/app_name" >
                <intent-filter>
                    <action android:name="android.intent.action.MAIN" />

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

            <service android:name="string.pub.service.IBinderService" android:process=":remote">
                <intent-filter >
                    <action android:name="string.pub.action.Binder"/>
                </intent-filter>
            </service>
        </application>

    </manifest>

实现效果如下所示：

可以看到，实进程间通信功能。