Netty从4.0版本就提供了连接池ChannelPool，可以解决与多个服务端交互以及与单个服务端建立连接池的问题
1、实现ChannelPoolHandler
首先要写一个类实现ChannelPoolHandler,主要是channelCreated,在channelCreated中添加channelhandler等
package com.bokeyuan.http.pool_client; import io.netty.channel.Channel; import io.netty.channel.pool.ChannelPoolHandler; import io.netty.channel.socket.SocketChannel; import io.netty.handler.codec.http.HttpClientCodec; import io.netty.handler.codec.http.HttpContentDecompressor; import io.netty.handler.codec.http.HttpObjectAggregator; import io.netty.handler.ssl.SslContext; import io.netty.handler.ssl.SslContextBuilder; import io.netty.handler.ssl.util.InsecureTrustManagerFactory; import io.netty.handler.timeout.IdleStateHandler; /** * @author: void * @date: 2021-09-10 17:52 * @description: 实现ChannelPoolHandler * @version: 1.0 */ public class NettyChannelPoolHandler implements ChannelPoolHandler { private boolean isSSL; public NettyChannelPoolHandler(boolean isSSL) { this.isSSL = isSSL; } @Override public void channelReleased(Channel channel) throws Exception { System.out.println("channelReleased. Channel ID:"+channel.id()); } @Override public void channelAcquired(Channel channel) throws Exception { System.out.println("channelAcquired. Channel ID:"+channel.id()); } @Override public void channelCreated(Channel channel) throws Exception { System.out.println("channelCreated. Channel ID："+channel.id()); SocketChannel socketChannel = (SocketChannel) channel; socketChannel.config().setKeepAlive(true); socketChannel.config().setTcpNoDelay(true); if (isSSL) { //配置Https通信 SslContext context = SslContextBuilder.forClient().trustManager(InsecureTrustManagerFactory.INSTANCE).build(); channel.pipeline().addLast(context.newHandler(channel.alloc())); } socketChannel.pipeline() //包含编码器和解码器 .addLast(new HttpClientCodec()) //聚合 .addLast(new HttpObjectAggregator(1024 * 10 * 1024)) //解压 .addLast(new HttpContentDecompressor()) //添加ChannelHandler .addLast(new NettyClientHandler()); channel.pipeline().addFirst(new IdleStateHandler(5, 5, 10)); } }
2、客户端Handler
实现ChannelInboundHandlerAdapter类，覆写channelRead()方法打印服务端响应的内容
package com.bokeyuan.http.pool_client; import io.netty.buffer.ByteBuf; import io.netty.channel.ChannelHandlerContext; import io.netty.channel.ChannelInboundHandlerAdapter; import io.netty.handler.codec.http.FullHttpResponse; import io.netty.handler.codec.http.HttpHeaders; import io.netty.util.CharsetUtil; import java.util.concurrent.atomic.AtomicInteger; /** * @author: void * @date: 2021-09-13 14:07 * @description: * @version: 1.0 */ public class NettyClientHandler extends ChannelInboundHandlerAdapter { static AtomicInteger count = new AtomicInteger(1); @Override public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { FullHttpResponse response = (FullHttpResponse) msg; ByteBuf content = response.content(); HttpHeaders headers = response.headers(); System.out.println(count.getAndIncrement()+": content:"+content.toString(CharsetUtil.UTF_8)); //System.out.println("headers:"+headers.get("content-type").toString()); } }
3、客户端从连接池获取连接发起请求
客户端实现连接池，其中ChannelPoolMap可用于与多个服务端建立链接，本例中采用FixedChannelPool建立与单个服务端最大连接数为2的连接池。在main函数里通过向连接池获取channel发送了十条消息。
package com.bokeyuan.http.pool_client; import io.netty.bootstrap.Bootstrap; import io.netty.buffer.Unpooled; import io.netty.channel.*; import io.netty.channel.nio.NioEventLoopGroup; import io.netty.channel.pool.AbstractChannelPoolMap; import io.netty.channel.pool.ChannelPoolMap; import io.netty.channel.pool.FixedChannelPool; import io.netty.channel.pool.SimpleChannelPool; import io.netty.channel.socket.nio.NioSocketChannel; import io.netty.handler.codec.http.*; import io.netty.handler.logging.LogLevel; import io.netty.handler.logging.LoggingHandler; import io.netty.util.concurrent.Future; import io.netty.util.concurrent.FutureListener; import lombok.extern.slf4j.Slf4j; import java.net.InetAddress; import java.net.InetSocketAddress; import java.net.URI; import java.net.URL; import java.nio.charset.StandardCharsets; import java.util.HashMap; import java.util.Map; import java.util.Objects; /** * @author: void * @date: 2021-09-13 14:17 * @description: * @version: 1.0 */ @Slf4j public class NettyPoolClient { final EventLoopGroup group = new NioEventLoopGroup(); final Bootstrap bootstrap = new Bootstrap(); ChannelPoolMap<String, SimpleChannelPool> poolMap; public void build() throws Exception{ bootstrap.group(group) .channel(NioSocketChannel.class) //连接超时时长 .option(ChannelOption.CONNECT_TIMEOUT_MILLIS, 10000) .option(ChannelOption.TCP_NODELAY,true) .option(ChannelOption.SO_KEEPALIVE,true) .handler(new LoggingHandler(LogLevel.ERROR)); poolMap = new AbstractChannelPoolMap<String, SimpleChannelPool>() { @Override protected SimpleChannelPool newPool(String key) { InetSocketAddress inetAddress = null; boolean isSSL = key.contains("https"); try { URI uri = new URI(key); if (Objects.isNull(uri)) { return null; } URL url = new URL(key); String host = url.getHost(); InetAddress address = InetAddress.getByName(host); if (!host.equalsIgnoreCase(address.getHostAddress())) { log.warn("域名连接"); inetAddress = new InetSocketAddress(address, isSSL ? 443 : 80); } else { log.warn("ip+port连接"); int port = url.getPort(); inetAddress = InetSocketAddress.createUnresolved(host, port); } } catch (Throwable e) { log.error("请求地址不合法：" + e); } if (Objects.nonNull(inetAddress)){ // return new FixedChannelPool(bootstrap.remoteAddress(inetAddress), handler, config.getMaxConnections()); return new FixedChannelPool(bootstrap.remoteAddress(inetAddress),new NettyChannelPoolHandler(isSSL),2); } return null; } }; } public static void main(String[] args) { testJpushHttp(); }
public static void testJpushHttp(){ try { NettyPoolClient client = new NettyPoolClient(); client.build(); /**请求报文*/ String msg = client.getMessage(); //报文头 Map<String,String> header = new HashMap<>(); header.put("Authorization","Basic NIU3YzE2ZTgxOWU0YjY0MmVjNjg3NWI3OjllOTU2YjdkZmZhNDBhYWU1ZTg4YzVmOQ=="); //请求接口url地址 String url = "https://bjapi.push.jiguang.cn/v3/push"; for(int i=0; i<10; i++) { HttpRequest fullHttpRequest = buildRequest(msg, url, true, header); SimpleChannelPool pool = client.poolMap.get(url); Future<Channel> f = pool.acquire(); f.addListener((FutureListener<Channel>) f1 -> { if (f1.isSuccess()) { Channel ch = f1.getNow(); ChannelFuture channelFuture = ch.writeAndFlush(fullHttpRequest); //刷出数据的同时进行监听刷出的结果 channelFuture.addListener(new ChannelFutureListener() { @Override public void operationComplete(ChannelFuture future) throws Exception { //这里中刷出成功，并不代表客户接收成功，刷出数据成功默认代表已完成发送 //System.out.println("http netty client刷出数据结果为：" + future.isSuccess()); } }); pool.release(ch); } }); } } catch (Exception e) { e.printStackTrace(); } } /** * 获取请求报文 * @return */ private String getMessage(){ String msg = "{ " + ""notification": " + " { " + " "android":{ " + " "alert":"alert-test", " + " "title":"title-test", " + " "style":1, " + " "alert_type":1, " + " "big_text":"big text content" " + " " + " }, " + " "winphone":{"alert":"alert-test","title":"title-test"}, " + " "ios":{"alert":"通知"} " + " " + " }, " + ""audience":{"registration_id":["180fe1da9e6b5af51a0"]}, " + ""options":{"apns_production":false,"time_to_live":86400}, " + ""platform":"all" " + "} "; return msg; } public static HttpRequest buildRequest(String msg, String url, boolean isKeepAlive) throws Exception{ return buildRequest(msg,url,isKeepAlive,null); } public static HttpRequest buildRequest(String msg, String url, boolean isKeepAlive, Map<String,String> headers) throws Exception { URL netUrl = new URL(url); URI uri = new URI(netUrl.getPath()); //构建http请求 DefaultFullHttpRequest request = new DefaultFullHttpRequest(HttpVersion.HTTP_1_1, HttpMethod.POST, uri.toASCIIString(), Unpooled.wrappedBuffer(msg.getBytes(StandardCharsets.UTF_8))); //设置请求的host(这里可以是ip,也可以是域名) request.headers().set(HttpHeaderNames.HOST, netUrl.getHost()); //其他头部信息 if (headers != null && !headers.isEmpty()) { for (Map.Entry<String, String> entry : headers.entrySet()) { request.headers().set(entry.getKey(), entry.getValue()); } } //设置返回Json request.headers().set(HttpHeaderNames.CONTENT_TYPE ,"text/json;charset=UTF-8"); //发送的长度 request.headers().set(HttpHeaderNames.CONTENT_LENGTH, request.content().readableBytes()); //是否是长连接 if (isKeepAlive){ request.headers().set(HttpHeaderNames.CONNECTION, HttpHeaderValues.KEEP_ALIVE); } //添加其他头部信息 // request.headers().set(HttpHeaderNames.ACCEPT, "*/*"); // request.headers().set(HttpHeaderNames.CACHE_CONTROL, "no-cache"); // request.headers().set(HttpHeaderNames.ACCEPT_ENCODING, "gzip, deflate, br"); // request.headers().set(HttpHeaderNames.USER_AGENT, "PostmanRuntime/7.28.4"); return request; } }
启动服务端，for循环里向服务端发送了10条消息
服务端输出如下，可以看到一共与服务端建立了2个channel，剩下的都是从连接池里请求连接和释放连接。
channelCreated. Channel ID：a648b534 channelCreated. Channel ID：ba8b236d channelReleased. Channel ID:a648b534 channelReleased. Channel ID:ba8b236d channelAcquired. Channel ID:ba8b236d channelAcquired. Channel ID:a648b534 channelReleased. Channel ID:a648b534 channelReleased. Channel ID:ba8b236d channelAcquired. Channel ID:ba8b236d channelAcquired. Channel ID:a648b534 channelReleased. Channel ID:ba8b236d channelAcquired. Channel ID:ba8b236d channelReleased. Channel ID:ba8b236d channelAcquired. Channel ID:ba8b236d channelReleased. Channel ID:a648b534 channelAcquired. Channel ID:a648b534 channelReleased. Channel ID:ba8b236d channelReleased. Channel ID:a648b534 channelAcquired. Channel ID:ba8b236d channelReleased. Channel ID:ba8b236d 1: content:{"sendno":"0","msg_id":"67554259084023244"} 2: content:{"sendno":"0","msg_id":"29273659053621966"} 3: content:{"sendno":"0","msg_id":"2252059060236999"} 4: content:{"sendno":"0","msg_id":"47288059060501707"} 5: content:{"sendno":"0","msg_id":"67554259083292593"} 6: content:{"sendno":"0","msg_id":"54043459060484452"} 7: content:{"sendno":"0","msg_id":"2252059060228806"} 8: content:{"sendno":"0","msg_id":"2252059059572541"} 9: content:{"sendno":"0","msg_id":"47288059059705497"} 10: content:{"sendno":"0","msg_id":"47288059060428558"}