[Android笔记] IPC系列之AIDL

2019-01-11 本文已影响1人 Zach_C

出于玉刚的《Android开发艺术探索》2.3.3-Binder

Demo源码

Book.java文件

// 实体类
package com.chen.interview.aidl;

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

public class Book implements Parcelable {

    private int id;
    private String name;

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

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

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

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

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

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

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

    @Override
    public String toString() {
        return "Book{" +
                "id=" + id +
                ", name='" + name + '\'' +
                '}';
    }
}

Book.aidl文件

package com.chen.interview.aidl;
parcelable Book;

IBookManager.aidl文件

// IMyService.aidl
package com.chen.interview.aidl;
import com.chen.interview.aidl.Book; // 注意：就算在同一个包名下也需手动导入

// Declare any non-default types here with import statements

interface IBookManager {
    List<Book> getBookList();
    void addBook(in Book book);
}

AS自动生成的IBookManager.java文件

/*
 * This file is auto-generated.  DO NOT MODIFY.
 * Original file: /Users/zehua_chen/Android/work/wrokspace/android/work_as/Interview/app/src/main/aidl/com/chen/interview/aidl/IBookManager.aidl
 */
package com.chen.interview.aidl;
// Declare any non-default types here with import statements

public interface IBookManager extends android.os.IInterface {
    /**
     * Local-side IPC implementation stub class.
     */
    public static abstract class Stub extends android.os.Binder implements com.chen.interview.aidl.IBookManager {
        // 唯一标识，一般用当前类名全称表示
        private static final java.lang.String DESCRIPTOR = "com.chen.interview.aidl.IBookManager";

        /**
         * Construct the stub at attach it to the interface.
         */
        public Stub() {
            this.attachInterface(this, DESCRIPTOR);
        }

        /**
         * 用户将服务端的Binder对象转换成客户端所需的AIDL接口类型额对象
         * 区分进程，如果服务端和客户端处于同一进程则返回服务端对象本身，否则返回Stub.Proxy对象
         *
         * Cast an IBinder object into an com.chen.interview.aidl.IBookManager interface,
         * generating a proxy if needed.
         */
        public static com.chen.interview.aidl.IBookManager asInterface(android.os.IBinder obj) {
            if ((obj == null)) {
                return null;
            }
            android.os.IInterface iin = obj.queryLocalInterface(DESCRIPTOR);
            if (((iin != null) && (iin instanceof com.chen.interview.aidl.IBookManager))) {
                // 同一进程
                return ((com.chen.interview.aidl.IBookManager) iin);
            }
            // 不同进程
            return new com.chen.interview.aidl.IBookManager.Stub.Proxy(obj);
        }

        /**
         * 用于返回当前Binder对象
         *
         * @return Binder
         */
        @Override
        public android.os.IBinder asBinder() {
            return this;
        }

        /**
         * 该方法运行与服务端的Binder线程池中，客户端发起请求时，远程请求会通过系统底层封装后交给此方法处理
         * @param code 确定客户端请求的目标方法
         * @param data 可从data获取目标方法所需的参数
         * @param reply 方法执行完会向reply写入返回值（如果有返回值）
         * @param flags 一些额外的标识，0表示正常的PRC，如果为
         * {@link android.os.Binder#FLAG_ONEWAY}即为1，表示单向的RPC
         * @return 返回false则表示客户端请求失败
         * @throws android.os.RemoteException
         */
        @Override
        public boolean onTransact(int code, android.os.Parcel data, android.os.Parcel reply, int flags) throws android.os.RemoteException {
            switch (code) {
                case INTERFACE_TRANSACTION: {
                    reply.writeString(DESCRIPTOR);
                    return true;
                }
                case TRANSACTION_getBookList: {
                    data.enforceInterface(DESCRIPTOR);
                    java.util.List<com.chen.interview.aidl.Book> _result = this.getBookList();
                    reply.writeNoException();
                    reply.writeTypedList(_result);
                    return true;
                }
                case TRANSACTION_addBook: {
                    data.enforceInterface(DESCRIPTOR);
                    com.chen.interview.aidl.Book _arg0;
                    if ((0 != data.readInt())) {
                        _arg0 = com.chen.interview.aidl.Book.CREATOR.createFromParcel(data);
                    } else {
                        _arg0 = null;
                    }
                    this.addBook(_arg0);
                    reply.writeNoException();
                    return true;
                }
            }
            return super.onTransact(code, data, reply, flags);
        }

        private static class Proxy implements com.chen.interview.aidl.IBookManager {
            private android.os.IBinder mRemote;

            Proxy(android.os.IBinder remote) {
                mRemote = remote;
            }

            @Override
            public android.os.IBinder asBinder() {
                return mRemote;
            }

            public java.lang.String getInterfaceDescriptor() {
                return DESCRIPTOR;
            }

            /**
             * 运行在客户端
             * @return
             * @throws android.os.RemoteException
             */
            @Override
            public java.util.List<com.chen.interview.aidl.Book> getBookList() throws android.os.RemoteException {
                android.os.Parcel _data = android.os.Parcel.obtain();
                android.os.Parcel _reply = android.os.Parcel.obtain();
                java.util.List<com.chen.interview.aidl.Book> _result;
                try {
                    _data.writeInterfaceToken(DESCRIPTOR);
                    // transact发起RPC，当前线程挂起，然后服务端的onTransact方法会被调用
                    mRemote.transact(Stub.TRANSACTION_getBookList, _data, _reply, 0);
                    // 直到PRC过程返回后，当前线程继续执行，若远程方式是耗时的，勿在主线程发起RPC请求
                    _reply.readException();
                    // 从_reply获取返回的数据
                    _result = _reply.createTypedArrayList(com.chen.interview.aidl.Book.CREATOR);
                } finally {
                    _reply.recycle();
                    _data.recycle();
                }
                return _result;
            }

            @Override
            public void addBook(com.chen.interview.aidl.Book book) throws android.os.RemoteException {
                android.os.Parcel _data = android.os.Parcel.obtain();
                android.os.Parcel _reply = android.os.Parcel.obtain();
                try {
                    _data.writeInterfaceToken(DESCRIPTOR);
                    if ((book != null)) {
                        _data.writeInt(1);
                        book.writeToParcel(_data, 0);
                    } else {
                        _data.writeInt(0);
                    }
                    mRemote.transact(Stub.TRANSACTION_addBook, _data, _reply, 0);
                    _reply.readException();
                } finally {
                    _reply.recycle();
                    _data.recycle();
                }
            }
        }

        static final int TRANSACTION_getBookList = (android.os.IBinder.FIRST_CALL_TRANSACTION + 0);
        static final int TRANSACTION_addBook = (android.os.IBinder.FIRST_CALL_TRANSACTION + 1);
    }

    public java.util.List<com.chen.interview.aidl.Book> getBookList() throws android.os.RemoteException;

    public void addBook(com.chen.interview.aidl.Book book) throws android.os.RemoteException;
}

IPC通信

服务端角色BookManagerService.java

public class BookManagerService extends Service {

    private static final String TAG = "BMS";

    private CopyOnWriteArrayList<Book> mBookList = new CopyOnWriteArrayList<>();

    private Binder mBinder = new IBookManager.Stub() {
        @Override
        public List<Book> getBookList() throws RemoteException {
            return mBookList;
        }

        @Override
        public void addBook(Book book) throws RemoteException {
            mBookList.add(book);
        }
    };

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

    @Override
    public void onCreate() {
        super.onCreate();
        mBookList.add(new Book(1, "java"));
        mBookList.add(new Book(2, "C++"));
        mBookList.add(new Book(3, "python"));
    }
}

客户端角色MainActivity.java

public class MainActivity extends Activity {

    private static final String TAG = "MainActivity";

    private ServiceConnection mConnection = new ServiceConnection() {
        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            IBookManager bookManager = IBookManager.Stub.asInterface(service);
            try {
                bookManager.addBook(new Book(4, "算法"));
                List<Book> bookList = bookManager.getBookList();
                Log.i(TAG, "list type: " + bookList.getClass().getCanonicalName());
                Log.i(TAG, "list: " + bookList);

            } catch (RemoteException e) {
                e.printStackTrace();
            }

        }

        @Override
        public void onServiceDisconnected(ComponentName name) {

        }
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Intent intent = new Intent(this, BookManagerService.class);
        bindService(intent, mConnection, Context.BIND_AUTO_CREATE);

        findViewById(R.id.btn1).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startActivity(new Intent(MainActivity.this, ProviderActivity.class));
            }
        });
    }

    @Override
    protected void onDestroy() {
        unbindService(mConnection);
        super.onDestroy();
    }

[Android笔记] IPC系列之AIDL

IPC通信

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