Netty使用实例

来源：互联网发布：unity3d 模型加载编辑：程序博客网时间：2024/06/06 08:44

贴上两个自己写好的例子，以便备注，以下两个例子基于netty-3.5.7.Final.jar用Junit进行测试

第一个例子：简单的发送字符串，接收字符串“Hello, World”

Java代码

package com.wujintao.netty;
import java.net.InetSocketAddress;
import java.util.concurrent.Executors;
import org.jboss.netty.bootstrap.ClientBootstrap;
import org.jboss.netty.bootstrap.ServerBootstrap;
import org.jboss.netty.channel.ChannelFuture;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.channel.ChannelPipeline;
import org.jboss.netty.channel.ChannelPipelineFactory;
import org.jboss.netty.channel.ChannelStateEvent;
import org.jboss.netty.channel.Channels;
import org.jboss.netty.channel.ExceptionEvent;
import org.jboss.netty.channel.MessageEvent;
import org.jboss.netty.channel.SimpleChannelHandler;
import org.jboss.netty.channel.socket.nio.NioClientSocketChannelFactory;
import org.jboss.netty.channel.socket.nio.NioServerSocketChannelFactory;
import org.jboss.netty.handler.codec.string.StringDecoder;
import org.jboss.netty.handler.codec.string.StringEncoder;
import org.junit.Test;
class HelloWorldServerHandler extends SimpleChannelHandler {
public void channelConnected(ChannelHandlerContext ctx, ChannelStateEvent e)
throws Exception {
e.getChannel().write("Hello, World");
}
public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e) {
System.out.println("Unexpected exception from downstream."
+ e.getCause());
e.getChannel().close();
}
}
class HelloWorldClientHandler extends SimpleChannelHandler {
public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) {
String message = (String) e.getMessage();
System.out.println(message);
e.getChannel().close();
}
public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e) {
System.out.println("Unexpected exception from downstream."
+ e.getCause());
e.getChannel().close();
}
}
/**
* Netty VS MinaNetty基于Pipeline处理，Mina基于Filter过滤
* Netty的事件驱动模型具有更好的扩展性和易用性
* Https，SSL，PB，RSTP，Text &Binary等协议支持
* Netty中UDP传输有更好的支持官方测试Netty比Mina性能更好
* @author Administrator
*
*/
public class TestCase {
public void testServer() {
//初始化channel的辅助类，为具体子类提供公共数据结构
ServerBootstrap bootstrap = new ServerBootstrap(
new NioServerSocketChannelFactory(
Executors.newCachedThreadPool(),
Executors.newCachedThreadPool()));
bootstrap.setPipelineFactory(new ChannelPipelineFactory() {
public ChannelPipeline getPipeline() {
ChannelPipeline pipeline = Channels.pipeline();
pipeline.addLast("decoder", new StringDecoder());
pipeline.addLast("encoder", new StringEncoder());
pipeline.addLast("handler", new HelloWorldServerHandler());
return pipeline;
}
});
//创建服务器端channel的辅助类,接收connection请求
bootstrap.bind(new InetSocketAddress(8080));
}
public void testClient() {
//创建客户端channel的辅助类,发起connection请求
ClientBootstrap bootstrap = new ClientBootstrap(
new NioClientSocketChannelFactory(
Executors.newCachedThreadPool(),
Executors.newCachedThreadPool()));
//It means one same HelloWorldClientHandler instance is going to handle multiple Channels and consequently the data will be corrupted.
//基于上面这个描述，必须用到ChannelPipelineFactory每次创建一个pipeline
bootstrap.setPipelineFactory(new ChannelPipelineFactory() {
public ChannelPipeline getPipeline() {
ChannelPipeline pipeline = Channels.pipeline();
pipeline.addLast("decoder", new StringDecoder());
pipeline.addLast("encoder", new StringEncoder());
pipeline.addLast("handler", new HelloWorldClientHandler());
return pipeline;
}
});
//创建无连接传输channel的辅助类(UDP),包括client和server
ChannelFuture future = bootstrap.connect(new InetSocketAddress(
"localhost", 8080));
future.getChannel().getCloseFuture().awaitUninterruptibly();
bootstrap.releaseExternalResources();
}
@Test
public void testNetty(){
testServer();
testClient();
}
}

第二个例子，实际应用中会用到这个，发送POJO类Persons [name=周杰伦123, age=31, salary=10000.44]

Java代码

package com.wujintao.netty;
import static org.jboss.netty.buffer.ChannelBuffers.dynamicBuffer;
import java.net.InetSocketAddress;
import java.util.concurrent.Executors;
import org.jboss.netty.bootstrap.ClientBootstrap;
import org.jboss.netty.bootstrap.ServerBootstrap;
import org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.channel.Channel;
import org.jboss.netty.channel.ChannelFactory;
import org.jboss.netty.channel.ChannelFuture;
import org.jboss.netty.channel.ChannelFutureListener;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.channel.ChannelPipeline;
import org.jboss.netty.channel.ChannelPipelineFactory;
import org.jboss.netty.channel.ChannelStateEvent;
import org.jboss.netty.channel.Channels;
import org.jboss.netty.channel.MessageEvent;
import org.jboss.netty.channel.SimpleChannelHandler;
import org.jboss.netty.channel.socket.nio.NioClientSocketChannelFactory;
import org.jboss.netty.channel.socket.nio.NioServerSocketChannelFactory;
import org.jboss.netty.handler.codec.frame.FrameDecoder;
import org.junit.Test;
/**
* 用POJO代替ChannelBuffer
*/
class TimeServerHandler3 extends SimpleChannelHandler {
@Override
public void channelConnected(ChannelHandlerContext ctx, ChannelStateEvent e)
throws Exception {
Persons person = new Persons("周杰伦123",31,10000.44);
ChannelFuture future = e.getChannel().write(person);
future.addListener(ChannelFutureListener.CLOSE);
}
}
class TimeClientHandler3 extends SimpleChannelHandler{
@Override
public void messageReceived(ChannelHandlerContext ctx, MessageEvent e)
throws Exception {
Persons person = (Persons)e.getMessage();
System.out.println(person);
e.getChannel().close();
}
}
/**
* FrameDecoder and ReplayingDecoder allow you to return an object of any type.
*
*/
class TimeDecoder extends FrameDecoder {
private final ChannelBuffer buffer = dynamicBuffer();
@Override
protected Object decode(ChannelHandlerContext ctx, Channel channel,
ChannelBuffer channelBuffer) throws Exception {
if(channelBuffer.readableBytes()<4) {
return null;
}
if (channelBuffer.readable()) {
// 读到,并写入buf
channelBuffer.readBytes(buffer, channelBuffer.readableBytes());
}
int namelength = buffer.readInt();
String name = new String(buffer.readBytes(namelength).array(),"GBK");
int age = buffer.readInt();
double salary = buffer.readDouble();
Persons person = new Persons(name,age,salary);
return person;
}
}
class TimeEncoder extends SimpleChannelHandler {
private final ChannelBuffer buffer = dynamicBuffer();
@Override
public void writeRequested(ChannelHandlerContext ctx, MessageEvent e)
throws Exception {
Persons person = (Persons)e.getMessage();
buffer.writeInt(person.getName().getBytes("GBK").length);
buffer.writeBytes(person.getName().getBytes("GBK"));
buffer.writeInt(person.getAge());
buffer.writeDouble(person.getSalary());
Channels.write(ctx, e.getFuture(), buffer);
}
}
class Persons{
private String name;
private int age;
private double salary;
public Persons(String name,int age,double salary){
this.name = name;
this.age = age;
this.salary = salary;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public double getSalary() {
return salary;
}
public void setSalary(double salary) {
this.salary = salary;
}
@Override
public String toString() {
return "Persons [name=" + name + ", age=" + age + ", salary=" + salary
+ "]";
}
}
public class TestCase5 {
public void testServer() {
ChannelFactory factory = new NioServerSocketChannelFactory(Executors.newCachedThreadPool(), Executors.newCachedThreadPool());
ServerBootstrap bootstrap = new ServerBootstrap(factory);
bootstrap.setPipelineFactory(new ChannelPipelineFactory() {
public ChannelPipeline getPipeline() throws Exception {
return Channels.pipeline(new TimeEncoder(), new TimeServerHandler3());
}
});
bootstrap.setOption("child.tcpNoDelay", true);
bootstrap.setOption("child.keepAlive", true);
bootstrap.bind(new InetSocketAddress("localhost",9999));
}
public void testClient(){
//创建客户端channel的辅助类,发起connection请求
ClientBootstrap bootstrap = new ClientBootstrap(
new NioClientSocketChannelFactory(
Executors.newCachedThreadPool(),
Executors.newCachedThreadPool()));
bootstrap.setPipelineFactory(new ChannelPipelineFactory() {
public ChannelPipeline getPipeline() {
ChannelPipeline pipeline = Channels.pipeline();
pipeline.addLast("decoder", new TimeDecoder());
pipeline.addLast("encoder", new TimeEncoder());
pipeline.addLast("handler", new TimeClientHandler3());
return pipeline;
}
});
//创建无连接传输channel的辅助类(UDP),包括client和server
ChannelFuture future = bootstrap.connect(new InetSocketAddress(
"localhost", 9999));
future.getChannel().getCloseFuture().awaitUninterruptibly();
bootstrap.releaseExternalResources();
}
@Test
public void testNetty() {
testServer();
testClient();
}
}

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