aidl demo调用原理
通过网络的例子,生成的BookManager如下所示:service和client都是相同的java文件生成的。
这个类的例子添加book和查询book两个例子
客户端创建bookmananger方法:
bookManager = BookManager.Stub.asInterface(iBinder);
客户端里的iBinder,是binderProxy类的
创建一个proxy的例子
点击添加后
点击后调用
mRemote.transact(Stub.TRANSACTION_addBook, _data, _reply, 0);----》》
调用BinderProxy类里的public boolean transact(int code, Parcel data, Parcel reply, int flags) throws RemoteException
接着调用Binder里面的execTransact,执行了native函数后,会自动执行下面的图片函数,进入service服务端的代码,下面代码是单独的进程,在binder
进程里面,所以不需要担心这里的操作。
执行BookManager里面的onTransact方法,
服务端代码如下图所示:
实现了Stub类的方法,
/* * This file is auto-generated. DO NOT MODIFY. * Original file: F:\\new_file\\demo\\aidl\\AidlService-master\\app\\src\\main\\aidl\\com\\example\\aidldemo\\BookManager.aidl */ package com.example.aidldemo; // Declare any non-default types here with import statements public interface BookManager extends android.os.IInterface { public java.util.List<com.example.aidldemo.Book> getBooks() throws android.os.RemoteException; public void addBook(com.example.aidldemo.Book book) throws android.os.RemoteException; /** * Local-side IPC implementation stub class. */ public static abstract class Stub extends android.os.Binder implements com.example.aidldemo.BookManager { static final int TRANSACTION_getBooks = (android.os.IBinder.FIRST_CALL_TRANSACTION + 0); static final int TRANSACTION_addBook = (android.os.IBinder.FIRST_CALL_TRANSACTION + 1); private static final java.lang.String DESCRIPTOR = "com.example.aidldemo.BookManager"; /** * Construct the stub at attach it to the interface. */ public Stub() { this.attachInterface(this, DESCRIPTOR); } /** * Cast an IBinder object into an com.example.aidldemo.BookManager interface, * generating a proxy if needed. */ public static com.example.aidldemo.BookManager asInterface(android.os.IBinder obj) { if ((obj == null)) { return null; } android.os.IInterface iin = obj.queryLocalInterface(DESCRIPTOR); if (((iin != null) && (iin instanceof com.example.aidldemo.BookManager))) { return ((com.example.aidldemo.BookManager) iin); } return new com.example.aidldemo.BookManager.Stub.Proxy(obj); } @Override public android.os.IBinder asBinder() { return this; } @Override public boolean onTransact(int code, android.os.Parcel data, android.os.Parcel reply, int flags) throws android.os.RemoteException { java.lang.String descriptor = DESCRIPTOR; switch (code) { case INTERFACE_TRANSACTION: { reply.writeString(descriptor); return true; } case TRANSACTION_getBooks: { data.enforceInterface(descriptor); java.util.List<com.example.aidldemo.Book> _result = this.getBooks(); reply.writeNoException(); reply.writeTypedList(_result); return true; } case TRANSACTION_addBook: { data.enforceInterface(descriptor); com.example.aidldemo.Book _arg0; if ((0 != data.readInt())) { _arg0 = com.example.aidldemo.Book.CREATOR.createFromParcel(data); } else { _arg0 = null; } this.addBook(_arg0); reply.writeNoException(); return true; } default: { return super.onTransact(code, data, reply, flags); } } } private static class Proxy implements com.example.aidldemo.BookManager { 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; } @Override public java.util.List<com.example.aidldemo.Book> getBooks() throws android.os.RemoteException { android.os.Parcel _data = android.os.Parcel.obtain(); android.os.Parcel _reply = android.os.Parcel.obtain(); java.util.List<com.example.aidldemo.Book> _result; try { _data.writeInterfaceToken(DESCRIPTOR); mRemote.transact(Stub.TRANSACTION_getBooks, _data, _reply, 0); _reply.readException(); _result = _reply.createTypedArrayList(com.example.aidldemo.Book.CREATOR); } finally { _reply.recycle(); _data.recycle(); } return _result; } @Override public void addBook(com.example.aidldemo.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(); } } } } }
总结:1、参数的传递过程,首先通过序列化在main线程里,进行转换成序列化数据,传递给remote对象,执行后remote结果参数会自动转换成方法的返回值;在binder进程里面会将序列化数据转换成类进行处理,处理的结果在binder线程里面也要转换成序列化数据,跨进程通讯只能传递序列化数据,传递实体类
2、客户端调用aild接口时候,会阻塞在主线程,所以耗时对 操作不要放在接口方法中,客户端通过transactNative方法进行阻塞主线程,通过回调的方式返回参数