android 中aidl

客户端与服务端通信是通过Binder；

aidl 方便的定义了通信的格式；

通过aidl文件生成的的java文件

例如：

aidl文件：

// IRemoteSer.aidl
 package com.example.myapplication;
 
 // Declare any non-default types here with import statements
 
 interface IRemoteSer {
     /**
      * Demonstrates some basic types that you can use as parameters
      * and return values in AIDL.
      */
     void basicTypes(int anInt, long aLong, boolean aBoolean, float aFloat,
             double aDouble, String aString);
    String test(int i, String m);
 
     void play();
 
 }

生成的java文件：

package com.example.myapplication;
// Declare any non-default types here with import statements

public interface IRemoteSer extends android.os.IInterface
{
/** Local-side IPC implementation stub class. */
public static abstract class Stub extends android.os.Binder implements com.example.myapplication.IRemoteSer
{
private static final java.lang.String DESCRIPTOR = "com.example.myapplication.IRemoteSer";
/** Construct the stub at attach it to the interface. */
public Stub()
{
this.attachInterface(this, DESCRIPTOR);
}
/**
 * Cast an IBinder object into an com.example.myapplication.IRemoteSer interface,
 * generating a proxy if needed.
 */
public static com.example.myapplication.IRemoteSer asInterface(android.os.IBinder obj)
{
if ((obj==null)) {
return null;
}
android.os.IInterface iin = obj.queryLocalInterface(DESCRIPTOR);
if (((iin!=null)&&(iin instanceof com.example.myapplication.IRemoteSer))) {
return ((com.example.myapplication.IRemoteSer)iin);
}
return new com.example.myapplication.IRemoteSer.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
{
switch (code)
{
case INTERFACE_TRANSACTION:
{
reply.writeString(DESCRIPTOR);
return true;
}
case TRANSACTION_basicTypes:
{
data.enforceInterface(DESCRIPTOR);
int _arg0;
_arg0 = data.readInt();
long _arg1;
_arg1 = data.readLong();
boolean _arg2;
_arg2 = (0!=data.readInt());
float _arg3;
_arg3 = data.readFloat();
double _arg4;
_arg4 = data.readDouble();
java.lang.String _arg5;
_arg5 = data.readString();
this.basicTypes(_arg0, _arg1, _arg2, _arg3, _arg4, _arg5);
reply.writeNoException();
return true;
}
case TRANSACTION_test:
{
data.enforceInterface(DESCRIPTOR);
int _arg0;
_arg0 = data.readInt();
java.lang.String _arg1;
_arg1 = data.readString();
java.lang.String _result = this.test(_arg0, _arg1);
reply.writeNoException();
reply.writeString(_result);
return true;
}
case TRANSACTION_play:
{
data.enforceInterface(DESCRIPTOR);
this.play();
reply.writeNoException();
return true;
}
}
return super.onTransact(code, data, reply, flags);
}
private static class Proxy implements com.example.myapplication.IRemoteSer
{
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;
}
/**
     * Demonstrates some basic types that you can use as parameters
     * and return values in AIDL.
     */
@Override public void basicTypes(int anInt, long aLong, boolean aBoolean, float aFloat, double aDouble, java.lang.String aString) throws android.os.RemoteException
{
android.os.Parcel _data = android.os.Parcel.obtain();
android.os.Parcel _reply = android.os.Parcel.obtain();
try {
_data.writeInterfaceToken(DESCRIPTOR);
_data.writeInt(anInt);
_data.writeLong(aLong);
_data.writeInt(((aBoolean)?(1):(0)));
_data.writeFloat(aFloat);
_data.writeDouble(aDouble);
_data.writeString(aString);
mRemote.transact(Stub.TRANSACTION_basicTypes, _data, _reply, 0);
_reply.readException();
}
finally {
_reply.recycle();
_data.recycle();
}
}
@Override public java.lang.String test(int i, java.lang.String m) throws android.os.RemoteException
{
android.os.Parcel _data = android.os.Parcel.obtain();
android.os.Parcel _reply = android.os.Parcel.obtain();
java.lang.String _result;
try {
_data.writeInterfaceToken(DESCRIPTOR);
_data.writeInt(i);
_data.writeString(m);
mRemote.transact(Stub.TRANSACTION_test, _data, _reply, 0);
_reply.readException();
_result = _reply.readString();
}
finally {
_reply.recycle();
_data.recycle();
}
return _result;
}
@Override public void play() throws android.os.RemoteException
{
android.os.Parcel _data = android.os.Parcel.obtain();
android.os.Parcel _reply = android.os.Parcel.obtain();
try {
_data.writeInterfaceToken(DESCRIPTOR);
mRemote.transact(Stub.TRANSACTION_play, _data, _reply, 0);
_reply.readException();
}
finally {
_reply.recycle();
_data.recycle();
}
}
}
static final int TRANSACTION_basicTypes = (android.os.IBinder.FIRST_CALL_TRANSACTION + 0);
static final int TRANSACTION_test = (android.os.IBinder.FIRST_CALL_TRANSACTION + 1);
static final int TRANSACTION_play = (android.os.IBinder.FIRST_CALL_TRANSACTION + 2);
}
/**
     * Demonstrates some basic types that you can use as parameters
     * and return values in AIDL.
     */
public void basicTypes(int anInt, long aLong, boolean aBoolean, float aFloat, double aDouble, java.lang.String aString) throws android.os.RemoteException;
public java.lang.String test(int i, java.lang.String m) throws android.os.RemoteException;
public void play() throws android.os.RemoteException;
}

内部抽象类Stub 对协议格式进行了实现； Stub.Proxy是客户端调用服务端方法的代理，通过transact方法实现；

服务端继承Stub实现IRemoteServce接口；    客户端拿到Binder ,   

new com.example.myapplication.IRemoteSer.Stub.Proxy(obj)

这个Binder是绑定到远程服务端的， 通过上面代理类进行数据传输；

下面是 messager的应用：

http://blog.youkuaiyun.com/lmj623565791/article/details/47017485；

messager跨进程使用handler；