netty客户端与服务端事例
netty客户端与服务端例子
package com.snailteam.netty;
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.LengthFieldBasedFrameDecoder;
import io.netty.handler.logging.LogLevel;
import io.netty.handler.logging.LoggingHandler;
/**
* 服务端Bootstrap
* @author
*
*/
public class NServer {
static final int PORT = 8080;
public static void main(String[] args) {
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 {
/**
Inbound: 1 ->2 ->3 ->n 顺序处理
Outbound: n ->n-1 ->n-2 .. ->1 逆序处理
*/
//new LengthFieldBasedFrameDecoder(1024*8*20, 0, 4,0,4) 最大1024*8*20位为接收数据包，从0，长4Byte是数据宽度，然后从0，长4Byte剔除后的byte数据包，传送 到后面的handler链处理
ch.pipeline().addLast(new LoggingHandler(LogLevel.DEBUG),new LengthFieldBasedFrameDecoder(1024*8*20, 0, 4,0,4), new NServerHandler());
}
});
// Bind and start to accept incoming connections.
b.bind(PORT).sync().channel().closeFuture().sync();
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
bossGroup.shutdownGracefully();
workerGroup.shutdownGracefully();
}
}
}
package com.snailteam.netty;
import java.nio.charset.Charset;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
public class NServerHandler extends SimpleChannelInboundHandler<ByteBuf> {
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
cause.printStackTrace();
ctx.close();
}
@Override
protected void channelRead0(ChannelHandlerContext ctx, ByteBuf msg)
throws Exception {
String str = msg.toString(Charset.forName("UTF-8"));
System.out.println("[ok]" +str );
str = "辛苦了"+str.substring(str.lastIndexOf(',')+1);
ctx.writeAndFlush(Unpooled.wrappedBuffer(str.getBytes()));
}
}
package com.snailteam.netty;
import io.netty.bootstrap.Bootstrap;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.Channel;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
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.LengthFieldPrepender;
import io.netty.handler.logging.LogLevel;
import io.netty.handler.logging.LoggingHandler;
/**
* 客户端Bootstrap
*
*/
public class Nclient {
public static void main(String[] args) {
EventLoopGroup group = new NioEventLoopGroup();
try {
Bootstrap b = new Bootstrap();
b.group(group).channel(NioSocketChannel.class).option(ChannelOption.TCP_NODELAY, true)
.handler(new ChannelInitializer<SocketChannel>() {
@Override
public void initChannel(SocketChannel ch)
throws Exception {
//LengthFieldPrepender 把发送的数据前加4Byte存储数据宽度，发送。
ch.pipeline().addLast(new LoggingHandler(LogLevel.DEBUG),new LengthFieldPrepender(4),
new NclientHandler());
}
});
StringBuilder sb = new StringBuilder();
for (int i = 0; i < 20; i++) {
sb.append("中华人民共和国" + i + ",");
}
// Bind and start to accept incoming connections.
Channel con = b.connect("localhost", NServer.PORT).sync().channel();
for (int i = 0; i < 900; i++) {
String str = sb.toString() + i;
con.writeAndFlush(Unpooled.wrappedBuffer(str.getBytes())).sync().get();
System.out.println(i);
}
con.close().sync();//异步退出
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
group.shutdownGracefully();
}
}
}
package com.snailteam.netty;
import java.nio.charset.Charset;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
public class NclientHandler extends SimpleChannelInboundHandler<ByteBuf> {
@Override
public void exceptionCaught(
ChannelHandlerContext ctx, Throwable cause) throws Exception {
cause.printStackTrace();
ctx.close();
}
@Override
protected void channelRead0(ChannelHandlerContext ctx, ByteBuf msg)
throws Exception {
System.out.println(msg.toString(Charset.forName("UTF-8")));
}
}
package com.snailteam.netty;
import java.util.List;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.ByteToMessageDecoder;
public class FrameDecoder extends ByteToMessageDecoder{
int lengthFeildLength = 4;
@Override
protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) throws Exception {
Object decoded = decode(ctx, in);
if (decoded != null) {
out.add(decoded);
}
}
private Object decode(ChannelHandlerContext ctx, ByteBuf in) {
if(in.readableBytes()<lengthFeildLength)return null;//
int index = in.readerIndex();
int len = in.readInt();//解析次数包中对象的大小
if(in.readableBytes()<len){//数据包的内容不全
in.readerIndex(index);//重置readerIndex
return null;
}
return in.readRetainedSlice(len);//截取完整的一个转码对象。
}
}
pom
<dependency> <groupId>io.netty</groupId> <artifactId>netty-example</artifactId> <version>4.1.6.Final</version> <exclusions> <exclusion> <artifactId>netty-tcnative</artifactId> <groupId>io.netty</groupId> </exclusion> </exclusions> </dependency> <dependency> <groupId>io.netty</groupId> <artifactId>netty-tcnative</artifactId> <version>1.1.33.Fork23</version> <classifier>windows-x86_64</classifier> </dependency>