AIDL的具体做法

前言

上次学习AIDL还是Eclipse+ADT的年代，平常也不怎么用，好记性不如烂笔头，现记录下具体做法。
AIDL：Android interface Definition Language，用于实现进程间通信
感谢：https://www.cnblogs.com/zhujiabin/p/6080806.html

正文

要实现的功能是：在app AIDLClient中，修改app AIDLServer中Book的价格，并返回Book对象。

app AIDLServer目录结构：

image.png

实体类Book

package com.app.aidlservice.aidlservice.bean;

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

public class Book implements Parcelable {
    private String name;
    private int price;

    public Book() {
    }

    public Book(String name, int price) {
        this.name = name;
        this.price = price;
    }

    //setter and getter......
    //......

    protected Book(Parcel in) {
        name = in.readString();
        price = in.readInt();
    }

    public static final Creator<Book> CREATOR = new Creator<Book>() {
        @Override
        public Book createFromParcel(Parcel in) {
            return new Book(in);
        }

        @Override
        public Book[] newArray(int size) {
            return new Book[size];
        }
    };

    @Override
    public int describeContents() {
        return 0;
    }

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeString(name);
        dest.writeInt(price);
    }

    public void readFromParcel(Parcel in) {
        name = in.readString();
        price = in.readInt();
    }

}

在main目录上new AIDL文件，如图

image.png

会生成自动生成与java目录平级的aidl目录，将IMyAidlInterface中的方法删掉，换成自己的方法。
注意导入Book类: 在aidl下面的 com.app.aidlservice.aidlservice包中新建/bean/Book.aidl。

// Book.aidl
package com.app.aidlservice.aidlservice.bean;

parcelable Book;

package com.app.aidlservice.aidlservice;
import com.app.aidlservice.aidlservice.bean.Book;
// Declare any non-default types here with import statements

interface IMyAidlInterface {
    /**
     * Demonstrates some basic types that you can use as parameters
     * and return values in AIDL.
     */
      Book getBook();
      void setPrice(int price);
}

BookService:

package com.app.aidlservice.aidlservice;

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

import com.app.aidlservice.aidlservice.bean.Book;

public class BookService extends Service {
    Book book;
    @Override
    public void onCreate() {
        super.onCreate();
        book = new Book("java 并发编程的艺术", 59);
    }

    @Override
    public IBinder onBind(Intent intent) {
        return new IMyAidlInterface.Stub() {
            @Override
            public Book getBook() throws RemoteException {
                return book;
            }

            @Override
            public void setPrice(int price) throws RemoteException {
                book.setPrice(price);
            }
        };
    }

    @Override
    public boolean onUnbind(Intent intent) {
        return super.onUnbind(intent);
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
    }
}

在清单文件中配置Service

 <service
            android:name=".BookService"
            android:enabled="true"
            android:exported="true">
            <intent-filter>
                <action android:name="com.app.aidlservice.BookService" />

                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </service>

app AIDLClient

image.png

将app AIDLService中的aidl包全部拷贝过来，涉及到的Book类也要放到对应的包名下。

在activity中来绑定服务。

package com.app.aidlservice.aidlclient;

import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.IBinder;
import android.os.RemoteException;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;

import com.app.aidlservice.aidlservice.IMyAidlInterface;
import com.app.aidlservice.aidlservice.bean.Book;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        findViewById(R.id.btn_bind).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent();
                intent.setAction("com.app.aidlservice.BookService");
                intent.setPackage("com.app.aidlservice.aidlservice");

                bindService(intent, conn, Context.BIND_AUTO_CREATE);
            }
        });
        findViewById(R.id.btn_set_price).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (iMyAidlInterface != null) {
                    try {
                        iMyAidlInterface.setPrice(100);
                    } catch (RemoteException e) {
                        e.printStackTrace();
                    }
                }
            }
        });
        findViewById(R.id.btn_get_book).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (iMyAidlInterface != null) {
                    try {
                        Book book = iMyAidlInterface.getBook();
                        Log.e("TAG", "Book Name: " + book.getName() + ", Book Price: " + book.getPrice());
                    } catch (RemoteException e) {
                        e.printStackTrace();
                    }
                }
            }
        });
    }

    private IMyAidlInterface iMyAidlInterface;
    private ServiceConnection conn = new ServiceConnection() {
        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            iMyAidlInterface = IMyAidlInterface.Stub.asInterface(service);
        }

        @Override
        public void onServiceDisconnected(ComponentName name) {

        }
    };
}

打印结果：

07-10 23:54:11.103 3468-3468/com.app.aidlservice.aidlclient E/TAG: Book Name: java 并发编程的艺术, Book Price: 100

可以看到，价格由之前的59，变为100。
至此，使用aidl实现了进程间通信。