既然是入门，那我们就在这里写一个简单的demo，客户端发送一个字符串到服务器端，服务器端接收字符串后再发送回客户端。
2.1、配置开发环境
1.安装jdk 2.去官网下载jar包 (或者通过pom构建) 2.2、认识下netty的client和server 一个netty应用模型，如下图所示，但需要明白一点的是，我们写的server会自动处理多客户端请求，理论上讲，处理并发的能力决定于我们的配置及jdk的极限。
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"brush:java;">package nettydemo.echo.server;
import io.netty.bootstrap.serverbootstrap;
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.nioserversocketchannel;
import java.net.inetsocketaddress;
import nettydemo.echo.handler.echoserverhandler;
public class echoserver {
private static final int port = 8080;
public void start() throws interruptedexception {
serverbootstrap b = new serverbootstrap();// 引导辅助程序
eventloopgroup group = new nioeventloopgroup();// 通过nio方式来接收连接和处理连接
try {
b.group(group);
b.channel(nioserversocketchannel.class);// 设置nio类型的channel
b.localaddress(new inetsocketaddress(port));// 设置监听端口
b.childhandler(new channelinitializer
我要评论package nettydemo.echo.handler;
import io.netty.buffer.unpooled;
import io.netty.channel.channelfuturelistener;
import io.netty.channel.channelhandlercontext;
import io.netty.channel.channelinboundhandleradapter;
import io.netty.channel.channelhandler.sharable;
/**
* sharable表示此对象在channel间共享
* handler类是我们的具体业务类
* */
@sharable//注解@sharable可以让它在channels间共享
public class echoserverhandler extends channelinboundhandleradapter{
public void channelread(channelhandlercontext ctx, object msg) {
system.out.println("server received data :" + msg);
ctx.write(msg);//写回数据，
}
public void channelreadcomplete(channelhandlercontext ctx) {
ctx.writeandflush(unpooled.empty_buffer) //flush掉所有写回的数据
.addlistener(channelfuturelistener.close); //当flush完成后关闭channel
}
public void exceptioncaught(channelhandlercontext ctx,throwable cause) {
cause.printstacktrace();//捕捉异常信息
ctx.close();//出现异常时关闭channel
}
}
package nettydemo.echo.client;
import io.netty.bootstrap.bootstrap;
import io.netty.channel.channelfuture;
import io.netty.channel.channelfuturelistener;
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 java.net.inetsocketaddress;
import nettydemo.echo.handler.echoclienthandler;
public class echoclient {
private final string host;
private final int port;
public echoclient(string host, int port) {
this.host = host;
this.port = port;
}
public void start() throws exception {
eventloopgroup group = new nioeventloopgroup();
try {
bootstrap b = new bootstrap();
b.group(group);
b.channel(niosocketchannel.class);
b.remoteaddress(new inetsocketaddress(host, port));
b.handler(new channelinitializer() {
public void initchannel(socketchannel ch) throws exception {
ch.pipeline().addlast(new echoclienthandler());
}
});
channelfuture f = b.connect().sync();
f.addlistener(new channelfuturelistener() {
public void operationcomplete(channelfuture future) throws exception {
if(future.issuccess()){
system.out.println("client connected");
}else{
system.out.println("server attemp failed");
future.cause().printstacktrace();
}
}
});
f.channel().closefuture().sync();
} finally {
group.shutdowngracefully().sync();
}
}
public static void main(string[] args) throws exception {
new echoclient("127.0.0.1", 3331).start();
}
} 1. 创建一个serverbootstrap实例package nettydemo.echo.handler;
import io.netty.buffer.bytebuf;
import io.netty.buffer.bytebufutil;
import io.netty.buffer.unpooled;
import io.netty.channel.channelhandlercontext;
import io.netty.channel.simplechannelinboundhandler;
import io.netty.channel.channelhandler.sharable;
import io.netty.util.charsetutil;
@sharable
public class echoclienthandler extends simplechannelinboundhandler {
/**
*此方法会在连接到服务器后被调用
* */
public void channelactive(channelhandlercontext ctx) {
ctx.write(unpooled.copiedbuffer("netty rocks!", charsetutil.utf_8));
}
/**
*此方法会在接收到服务器数据后调用
* */
public void channelread0(channelhandlercontext ctx, bytebuf in) {
system.out.println("client received: " + bytebufutil.hexdump(in.readbytes(in.readablebytes())));
}
/**
*捕捉到异常
* */
public void exceptioncaught(channelhandlercontext ctx, throwable cause) {
cause.printstacktrace();
ctx.close();
}
}
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(精华)2020年7月21日 ASP.NET Core 容器伪属性注入
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