httpClient连接池 出现原因：多线程创建hppt请求调用远程接口
排查方法：
# java.net.SocketException: No buffer space available (maximum connections reached?): connect
有兴趣可以看原文！
本地cmd：
netstat -ano （windows下查看当前所有的连接），发现大量的TCP连接
打开任务管理器，查看PID为60204的进程，发现是个Java进程，如图：
解决：使用 httpClient连接池
导入的jar包
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.5.2</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpmime</artifactId>
<version>4.5.2</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpasyncclient</artifactId>
<version>4.1.4</version>
</dependency>
源码（直接复制就行）
import com.alibaba.fastjson.JSONObject;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.io.IOUtils;
import org.apache.http.*;
import org.apache.http.client.HttpRequestRetryHandler;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.methods.HttpRequestBase;
import org.apache.http.client.protocol.HttpClientContext;
import org.apache.http.config.Registry;
import org.apache.http.config.RegistryBuilder;
import org.apache.http.conn.ConnectTimeoutException;
import org.apache.http.conn.routing.HttpRoute;
import org.apache.http.conn.socket.ConnectionSocketFactory;
import org.apache.http.conn.socket.LayeredConnectionSocketFactory;
import org.apache.http.conn.socket.PlainConnectionSocketFactory;
import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import org.apache.http.message.BasicNameValuePair;
import javax.net.ssl.SSLException;
import javax.net.ssl.SSLHandshakeException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InterruptedIOException;
import java.io.UnsupportedEncodingException;
import java.net.UnknownHostException;
import java.util.*;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;
@Slf4j
public class HttpConnectionPoolUtil {
private static final int CONNECT_TIMEOUT = 30 * 1000;// 设置连接建立的超时时间为10s
private static final int SOCKET_TIMEOUT = 30 * 1000; // 设置等待数据超时时间30秒钟 根据业务调整
private static final int MAX_CONN = 30; // 最大连接数
private static final int MAX_PRE_ROUTE = 15;// 每个主机的并发
private static final int MAX_ROUTE = 15; // 目标主机的最大连接数
private static final long HTTP_IDEL_TIMEOUT = 5000;
private static final long HTTP_MONITOR_INTERVAL = 10 * 1000; // HTTP监控间隔
private static CloseableHttpClient httpClient; // 发送请求的客户端单例
private static PoolingHttpClientConnectionManager manager; //连接池管理类
private static ScheduledExecutorService monitorExecutor;
private final static Object syncLock = new Object(); // 相当于线程锁,用于线程安全
/**
* 对http请求进行基本设置
* @param httpRequestBase http请求
*/
private static void setRequestConfig(HttpRequestBase httpRequestBase){
RequestConfig requestConfig = RequestConfig.custom().setConnectionRequestTimeout(CONNECT_TIMEOUT)
.setConnectTimeout(CONNECT_TIMEOUT)
.setSocketTimeout(SOCKET_TIMEOUT).build();
httpRequestBase.setConfig(requestConfig);
}
public static CloseableHttpClient getHttpClient(String url){
String hostName = url.split("/")[2];
// System.out.println(hostName);
int port = 80;
if (hostName.contains(":")){
String[] args = hostName.split(":");
hostName = args[0];
port = Integer.parseInt(args[1]);
}
if (httpClient == null){
//多线程下多个线程同时调用getHttpClient容易导致重复创建httpClient对象的问题,所以加上了同步锁
synchronized (syncLock){
if (httpClient == null){
httpClient = createHttpClient(hostName, port);
//开启监控线程,对异常和空闲线程进行关闭
monitorExecutor = Executors.newScheduledThreadPool(1);
monitorExecutor.scheduleAtFixedRate(new TimerTask() {
@Override
public void run() {
// log.warn("close expired and idle for over 5s connection");
//关闭异常连接
manager.closeExpiredConnections();
//关闭5s空闲的连接
manager.closeIdleConnections(HTTP_IDEL_TIMEOUT, TimeUnit.MILLISECONDS);
// log.info("close expired and idle for over 5s connection");
}
}, HTTP_MONITOR_INTERVAL, HTTP_MONITOR_INTERVAL, TimeUnit.MILLISECONDS);
}
}
}
return httpClient;
}
/**
* 根据host和port构建httpclient实例
* @param host 要访问的域名
* @param port 要访问的端口
* @return
*/
public static CloseableHttpClient createHttpClient(String host, int port){
ConnectionSocketFactory plainSocketFactory = PlainConnectionSocketFactory.getSocketFactory();
LayeredConnectionSocketFactory sslSocketFactory = SSLConnectionSocketFactory.getSocketFactory();
Registry<ConnectionSocketFactory> registry = RegistryBuilder.<ConnectionSocketFactory> create().register("http", plainSocketFactory)
.register("https", sslSocketFactory).build();
manager = new PoolingHttpClientConnectionManager(registry);
//设置连接参数
manager.setMaxTotal(MAX_CONN); // 最大连接数
manager.setDefaultMaxPerRoute(MAX_PRE_ROUTE); // 路由最大连接数
HttpHost httpHost = new HttpHost(host, port);
manager.setMaxPerRoute(new HttpRoute(httpHost), MAX_ROUTE);
//请求失败时,进行请求重试
HttpRequestRetryHandler handler = (e,i,httpContext)->{
if (i > 3){
//重试超过3次,放弃请求
log.error("retry has more than 3 time, give up request");
return false;
}
if (e instanceof NoHttpResponseException){
//服务器没有响应,可能是服务器断开了连接,应该重试
log.error("receive no response from server, retry");
return true;
}
if (e instanceof SSLHandshakeException){
// SSL握手异常
log.error("SSL hand shake exception");
return false;
}
if (e instanceof InterruptedIOException){
//超时
log.error("InterruptedIOException");
return false;
}
if (e instanceof UnknownHostException){
// 服务器不可达
log.error("server host unknown");
return false;
}
if (e instanceof ConnectTimeoutException){
// 连接超时
log.error("Connection Time out");
return false;
}
if (e instanceof SSLException){
log.error("SSLException");
return false;
}
HttpClientContext context = HttpClientContext.adapt(httpContext);
org.apache.http.HttpRequest request = context.getRequest();
if (!(request instanceof HttpEntityEnclosingRequest)){
//如果请求不是关闭连接的请求
return true;
}
return false;
};
CloseableHttpClient client = HttpClients.custom().setConnectionManager(manager).setRetryHandler(handler).build();
return client;
}
/**
* 设置post请求的参数
* @param httpPost
* @param params
*/
private static void setPostParams(HttpPost httpPost, Map<String, String> params){
List<NameValuePair> nvps = new ArrayList<NameValuePair>();
Set<String> keys = params.keySet();
for (String key: keys){
nvps.add(new BasicNameValuePair(key, params.get(key)));
}
try {
httpPost.setEntity(new UrlEncodedFormEntity(nvps, "utf-8"));
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
}
public static String post(String url, String data) throws IOException {
HttpPost httpPost = new HttpPost(url);
setRequestConfig(httpPost);
// setPostParams(httpPost, params);
httpPost.setEntity(new StringEntity(data, ContentType.create("application/x-www-form-urlencoded", "utf-8")));
CloseableHttpResponse response = null;
InputStream in = null;
JSONObject object = null;
try {
response = getHttpClient(url).execute(httpPost, HttpClientContext.create());
HttpEntity entity = response.getEntity();
if (entity != null) {
in = entity.getContent();
String result = IOUtils.toString(in, "utf-8");
return result;
// object = JSONObject.parseObject(result);
}
throw new RuntimeException("远程连接异常！");
} finally {
try{
if (in != null) in.close();
if (response != null) response.close();
} catch (IOException e) {
e.printStackTrace();
}
}
// return object;
}
/**
* 关闭连接池
*/
public static void closeConnectionPool(){
try {
httpClient.close();
manager.close();
monitorExecutor.shutdown();
} catch (IOException e) {
e.printStackTrace();
}
}
}
感谢：
