对于Netty在这里就不做过多介绍了，详情咨询http://netty.io/wiki/user-guide-for-4.x.html
我们在使用netty的过程中肯定会遇到传输对象的情况，Netty4通过ObjectEncoder和ObjectDecoder来支持。
首先我们定义一个User对象，一定要实现Serializable接口：
import java.io.Serializable;/**
* User: hupeng
* Date: 14-6-3
* Time: 上午1:31
*/
public class User implements Serializable {private int id;
private String name;
private String cardNo;
private String description;
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;
}public String getCardNo() {
return cardNo;
}public void setCardNo(String cardNo) {
this.cardNo = cardNo;
}public String getDescription() {
return description;
}public void setDescription(String description) {
this.description = description;
}@Override
public String toString() {
return "User{" +
"id=" + id +
", name=‘" + name + ‘\‘‘ +
", cardNo=‘" + cardNo + ‘\‘‘ +
", description=‘" + description + ‘\‘‘ +
‘}‘;
}
}
然后定义一个客户端：
import io.netty.bootstrap.Bootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;
import io.netty.handler.codec.serialization.ClassResolvers;
import io.netty.handler.codec.serialization.ObjectDecoder;
import io.netty.handler.codec.serialization.ObjectEncoder;public class ObjectTransferClient {
private String host;private int port;
private int messageSize;
public ObjectTransferClient(String host, int port, int messageSize) {
this.host = host;
this.port = port;
this.messageSize = messageSize;
}public void run() throws InterruptedException {
Bootstrap bootstrap = new Bootstrap();
EventLoopGroup eventLoopGroup = new NioEventLoopGroup();try {
bootstrap.group(eventLoopGroup)
.channel(NioSocketChannel.class)
.handler(new ChannelInitializer<SocketChannel>() {
@Override
protected void initChannel(SocketChannel ch) throws Exception {
ch.pipeline().addLast(
new ObjectEncoder(),
new ObjectDecoder(Integer.MAX_VALUE ,ClassResolvers.cacheDisabled(null)),
new ObjectTransferClientHandler(messageSize));
}
});ChannelFuture future = bootstrap.connect(host, port).sync();
future.channel().closeFuture().sync();
} finally {
eventLoopGroup.shutdownGracefully();
}
}public static void main(String[] args) throws Exception {
final String host = "127.0.0.1";
final int port = 8080;
final int messageSize = 200;new ObjectTransferClient(host, port, messageSize).run();
}
}
以及客户端的一个handler
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;import java.util.ArrayList;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;public class ObjectTransferClientHandler extends ChannelInboundHandlerAdapter {
private static final Logger logger = Logger.getLogger(
ObjectTransferClientHandler.class.getName());private final List<User> message;
/**
* Creates a client-side handler.
*/
public ObjectTransferClientHandler(int messageSize) {
if (messageSize <= 0) {
throw new IllegalArgumentException(
"firstMessageSize: " + messageSize);
}
message = new ArrayList<User>(messageSize);
for (int i = 0; i < messageSize; i ++) {
User user = new User();
user.setId(i);
user.setCardNo("420000" + i);
user.setName("hu" +i);
user.setDescription("你觉得这样好吗？？真的好吗" + i);
message.add(user);
}
}@Override
public void channelActive(ChannelHandlerContext ctx) throws Exception {
// Send the message to Server
ctx.writeAndFlush(message);
}@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
// you can use the Object from Server here
System.out.println(msg);
ctx.close();
}@Override
public void exceptionCaught(
ChannelHandlerContext ctx, Throwable cause) throws Exception {
logger.log(
Level.WARNING,
"Unexpected exception from downstream.", cause);
ctx.close();
}
}
然后是服务端：
import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.codec.serialization.ClassResolvers;
import io.netty.handler.codec.serialization.ObjectDecoder;
import io.netty.handler.codec.serialization.ObjectEncoder;public class ObjectTranferServer {
private final int port;
public ObjectTranferServer(int port) {
this.port = port;
}public void run() throws Exception {
EventLoopGroup bossGroup = new NioEventLoopGroup(1);
EventLoopGroup workerGroup = new NioEventLoopGroup();
try {
ServerBootstrap b = new ServerBootstrap();
b.group(bossGroup, workerGroup)
.channel(NioServerSocketChannel.class)
.childHandler(new ChannelInitializer<SocketChannel>() {
@Override
public void initChannel(SocketChannel ch) throws Exception {
ch.pipeline().addLast(
new ObjectEncoder(),
new ObjectDecoder(Integer.MAX_VALUE,ClassResolvers.cacheDisabled(null)),
new ObjectTransferServerHandler());
}
});// Bind and start to accept incoming connections.
b.bind(port).sync().channel().closeFuture().sync();
} finally {
bossGroup.shutdownGracefully();
workerGroup.shutdownGracefully();
}
}public static void main(String[] args) throws Exception {
int port;
if (args.length > 0) {
port = Integer.parseInt(args[0]);
} else {
port = 8080;
}
new ObjectTranferServer(port).run();
}
}
服务端Handler：
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;import java.util.logging.Level;
import java.util.logging.Logger;public class ObjectTransferServerHandler extends ChannelInboundHandlerAdapter {
private static final Logger logger = Logger.getLogger(
ObjectTransferServerHandler.class.getName());@Override
public void channelRead(
ChannelHandlerContext ctx, Object msg) throws Exception {
System.out.println(msg);
ctx.write(msg);
}@Override
public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
ctx.flush();
ctx.close();
}@Override
public void exceptionCaught(
ChannelHandlerContext ctx, Throwable cause) throws Exception {
logger.log(
Level.WARNING,
"Unexpected exception from downstream.", cause);
ctx.close();
}
}
这里我传入的size为200的一个list对象。
当我把size增加到1000的时候，客户端和服务端都不报任何错误，但是也接收不到值。。具体原因还在寻找中，如果亲爱的你，可以指点一下我，那简直就是太好了。。。。
当然我们也可以采取其他方式，比如在客户端和服务端，通过json来序列化和反序列化传递，然后按照String来处理就行了