Netty 教程 – 序列化-JDK自带

开发例程

• 在服务端ChannelPipeline新增解码器io.netty.handler.codec.serialization.ObjectDecoder
• 在服务端ChannelPipeline新增解码器io.netty.handler.codec.serialization.ObjectEncoder
• 实体类实现java.io.Serializable序列化接口

1.创建OrderRequest 与 OrderResponse两个Java类

public class OrderRequest implements java.io.Serializable {

    private static final long serialVersionUID = 1826067782744144943L;
    private Integer orderId;
    private String userName;
    private String productName;
    private String phoneNumber;
    private String address;
    //省略 get set ..
}

public class OrderResponse implements java.io.Serializable {

    private static final long serialVersionUID = -5003946216600820264L;
    private Integer orderId;
    private String respCode;
    private String desc;

}

OrderServer

1.重写ChannelInitializer中的initChannel方法，添加ObjectDecoder解码器与ObjectEncoder编码器

@Override
protected void initChannel(SocketChannel channel) throws Exception {
    channel.pipeline().addLast(new ObjectDecoder(1024 * 1024, ClassResolvers.weakCachingResolver(this.getClass().getClassLoader())));
    channel.pipeline().addLast(new ObjectEncoder());
    channel.pipeline().addLast(new OrderServerHandler());
}

注意 ObjectDecoder(int maxObjectSize, ClassResolver classResolver)，第一个参数是设置序列化对象的最大字节长度，如果超出限定范围会抛出StreamCorruptedException，默认（1024 * 1024 = 1048576字节），第二个参数用于做类解码操作

2.创建OrderServerHandler，然后将接收到的消息做过滤，满足条件回写消息事件

private static class OrderServerHandler extends ChannelHandlerAdapter {

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        OrderRequest request = (OrderRequest) msg;
        if ("Levin".equalsIgnoreCase(request.getUserName())) {//如果是Levin购买的,返回消息
            System.out.println("Service Accept Client Order Request :[" + request.toString() + "]");
            ctx.writeAndFlush(response(request.getOrderId()));
        }
    }
    private OrderResponse response(Integer orderId) {
        OrderResponse response = new OrderResponse();
        response.setOrderId(orderId);
        response.setRespCode("200");
        response.setDesc("下单成功");
        return response;
    }
}

OrderClient

1.创建OrderClientHandler，请求3次然后将数据写入缓冲区后调用flush发送

private static class OrderClientHandler extends ChannelHandlerAdapter {

    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        for (int i = 1; i <= 3; i++) {
            ctx.write(request(i));
        }
        ctx.flush();
    }
    private Object request(int i) {
        OrderRequest request = new OrderRequest();
        request.setAddress("上海市青浦区赵重公路1888号");
        request.setOrderId(i);
        request.setPhoneNumber("130XXXX1912");
        request.setProductName("一起来学Netty");
        request.setUserName("Levin");
        return request;
    }
    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        System.out.println("Receive Server Response :[" + msg + "]");
    }
}

试验一把

分别启动OrderServer和OrderClient，将会看到如下日志

绑定端口,同步等待成功......
Service Accept Client Order Request :[OrderRequest{orderId=1, userName='Levin', productName='一起来学Netty', phoneNumber='130XXXX1912', address='上海市青浦区赵重公路1888号'}]
Service Accept Client Order Request :[OrderRequest{orderId=2, userName='Levin', productName='一起来学Netty', phoneNumber='130XXXX1912', address='上海市青浦区赵重公路1888号'}]
Service Accept Client Order Request :[OrderRequest{orderId=3, userName='Levin', productName='一起来学Netty', phoneNumber='130XXXX1912', address='上海市青浦区赵重公路1888号'}]

---------------------------------------------------------------------------------------------------------
Receive Server Response :[OrderResponse{orderId=1, respCode='200', desc='下单成功'}]
Receive Server Response :[OrderResponse{orderId=2, respCode='200', desc='下单成功'}]
Receive Server Response :[OrderResponse{orderId=3, respCode='200', desc='下单成功'}]