[DUBBO-3243] Fix Invalid use of BasicClientConnManager: connection still allocated #3243 (#3581)

Author: CrazyHZM

dubbo-rpc/dubbo-rpc-hessian/src/main/java/com/alibaba/dubbo/rpc/protocol/hessian/HessianProtocol.java

@@ -109,7 +109,9 @@ protected <T> T doRefer(Class<T> serviceType, URL url) throws RpcException {
         hessianProxyFactory.setOverloadEnabled(isOverloadEnabled);
         String client = url.getParameter(Constants.CLIENT_KEY, Constants.DEFAULT_HTTP_CLIENT);
         if ("httpclient".equals(client)) {
-            hessianProxyFactory.setConnectionFactory(new HttpClientConnectionFactory());
+            HessianConnectionFactory factory = new HttpClientConnectionFactory();
+            factory.setHessianProxyFactory(hessianProxyFactory);
+            hessianProxyFactory.setConnectionFactory(factory);
         } else if (client != null && client.length() > 0 && !Constants.DEFAULT_HTTP_CLIENT.equals(client)) {
             throw new IllegalStateException("Unsupported http protocol client=\"" + client + "\"!");
         } else {

dubbo-rpc/dubbo-rpc-hessian/src/main/java/com/alibaba/dubbo/rpc/protocol/hessian/HttpClientConnectionFactory.java

@@ -22,8 +22,8 @@
 import com.caucho.hessian.client.HessianConnectionFactory;
 import com.caucho.hessian.client.HessianProxyFactory;
 import org.apache.http.client.HttpClient;
-import org.apache.http.impl.client.DefaultHttpClient;
-import org.apache.http.params.HttpConnectionParams;
+import org.apache.http.client.config.RequestConfig;
+import org.apache.http.impl.client.HttpClientBuilder;
 
 import java.io.IOException;
 import java.net.URL;
@@ -33,12 +33,15 @@
  */
 public class HttpClientConnectionFactory implements HessianConnectionFactory {
 
-    private final HttpClient httpClient = new DefaultHttpClient();
+    private HttpClient httpClient;
 
     @Override
     public void setHessianProxyFactory(HessianProxyFactory factory) {
-        HttpConnectionParams.setConnectionTimeout(httpClient.getParams(), (int) factory.getConnectTimeout());
-        HttpConnectionParams.setSoTimeout(httpClient.getParams(), (int) factory.getReadTimeout());
+        RequestConfig requestConfig = RequestConfig.custom()
+                .setConnectionRequestTimeout((int) factory.getConnectTimeout())
+                .setSocketTimeout((int) factory.getReadTimeout())
+                .build();
+        httpClient = HttpClientBuilder.create().setDefaultRequestConfig(requestConfig).build();
     }
 
     @Override