I used httpclient 4.4 to send get and post request. and i just created a simpile wrapper of httpclient for easy use:
package com.u8.server.sdk;
import com.sun.net.httpserver.Headers;
import com.u8.server.log.Log;
import org.apache.http.Header;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.HttpRequestRetryHandler;
import org.apache.http.client.ResponseHandler;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.config.Registry;
import org.apache.http.config.RegistryBuilder;
import org.apache.http.conn.socket.ConnectionSocketFactory;
import org.apache.http.conn.socket.PlainConnectionSocketFactory;
import org.apache.http.conn.ssl.NoopHostnameVerifier;
import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
import org.apache.http.conn.ssl.TrustStrategy;
import org.apache.http.entity.ByteArrayEntity;
import org.apache.http.impl.client.BasicCookieStore;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import org.apache.http.impl.cookie.BasicClientCookie;
import org.apache.http.message.BasicHeader;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.protocol.HttpContext;
import org.apache.http.ssl.SSLContextBuilder;
import org.apache.http.util.EntityUtils;
import org.springframework.util.StringUtils;
import javax.net.ssl.HostnameVerifier;
import javax.net.ssl.SSLContext;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.CookiePolicy;
import java.net.URLEncoder;
import java.nio.charset.Charset;
import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
/**
* Created by ant on 2015/10/12.
*/
public class UHttpAgent {
private int connectTimeout = 5000; //5s
private int socketTimeout = 5000; //5s
private int maxTotalConnections = 200;
private static UHttpAgent instance;
private CloseableHttpClient httpClient;
private UHttpAgent(){
}
public static UHttpAgent getInstance(){
if(instance == null){
instance = new UHttpAgent();
}
return instance;
}
public static UHttpAgent newInstance(){
return new UHttpAgent();
}
public String get(String url, Map params){
return get(url, null, params, "UTF-8");
}
public String post(String url, Map params){
return post(url, null, params, "UTF-8");
}
public String get(String url , Map headers, Map params, String encoding){
if(this.httpClient == null){
init();
}
String fullUrl = url;
String urlParams = parseGetParams(params, encoding);
if (urlParams != null)
{
if (url.contains("?"))
{
fullUrl = url + "&" + urlParams;
}
else
{
fullUrl = url + "?" + urlParams;
}
}
Log.d("the full url is "+ fullUrl);
HttpGet getReq = new HttpGet(fullUrl.trim());
getReq.setHeaders(parseHeaders(headers));
ResponseHandler responseHandler = new ResponseHandler() {
@Override
public String handleResponse(HttpResponse httpResponse) throws IOException {
HttpEntity entity = httpResponse.getEntity();
return entity != null ? EntityUtils.toString(entity) : null;
}
};
try {
String res = httpClient.execute(getReq, responseHandler);
return res;
} catch (Exception e) {
e.printStackTrace();
}finally {
getReq.releaseConnection();
}
return null;
}
public String post(String url, Map headers, Map params, String encoding){
List pairs = new ArrayList();
if(params != null){
for(String key : params.keySet()){
pairs.add(new BasicNameValuePair(key, params.get(key)));
}
}
return post(url, headers, new UrlEncodedFormEntity(pairs, Charset.forName(encoding)));
}
public String post(String url, Map headers, HttpEntity entity){
if(this.httpClient == null) {
init();
}
HttpPost httpPost = new HttpPost(url);
httpPost.setHeaders(parseHeaders(headers));
httpPost.setEntity(entity);
ResponseHandler responseHandler = new ResponseHandler() {
@Override
public String handleResponse(HttpResponse httpResponse) throws IOException {
HttpEntity entity = httpResponse.getEntity();
return entity != null ? EntityUtils.toString(entity) : null;
}
};
try {
String body = httpClient.execute(httpPost, responseHandler);
return body;
} catch (IOException e) {
e.printStackTrace();
}finally {
httpPost.releaseConnection();
}
return null;
}
private Header[] parseHeaders(Map headers){
if(null == headers || headers.isEmpty()){
return getDefaultHeaders();
}
Header[] hs = new BasicHeader[headers.size()];
int i = 0;
for(String key : headers.keySet()){
hs[i] = new BasicHeader(key, headers.get(key));
i++;
}
return hs;
}
private Header[] getDefaultHeaders(){
Header[] hs = new BasicHeader[2];
hs[0] = new BasicHeader("Content-Type", "application/x-www-form-urlencoded");
hs[1] = new BasicHeader("User-Agent", "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/33.0.1750.146 Safari/537.36");
return hs;
}
private String parseGetParams(Map data, String encoding){
if(data == null || data.size() keyItor = data.keySet().iterator();
while(keyItor.hasNext()){
String key = keyItor.next();
String val = data.get(key);
try {
result.append(key).append("=").append(URLEncoder.encode(val, encoding).replace("+", "%2B")).append("&");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
}
return result.deleteCharAt(result.length() - 1).toString();
}
private void init(){
RequestConfig requestConfig = RequestConfig.custom()
.setConnectTimeout(connectTimeout)
.setSocketTimeout(socketTimeout)
.setExpectContinueEnabled(true)
.setAuthenticationEnabled(true)
.build();
HttpRequestRetryHandler retryHandler = new HttpRequestRetryHandler() {
@Override
public boolean retryRequest(IOException e, int retryNum, HttpContext httpContext) {
if(retryNum >= 3){
return false;
}
if(e instanceof org.apache.http.NoHttpResponseException
|| e instanceof org.apache.http.client.ClientProtocolException
|| e instanceof java.net.SocketException){
return true;
}
return false;
}
};
try{
SSLContext sslContext = new SSLContextBuilder().loadTrustMaterial(null, new TrustStrategy() {
@Override
public boolean isTrusted(X509Certificate[] chain, String authType) throws CertificateException {
return true;
}
}).build();
HostnameVerifier hostnameVerifier = NoopHostnameVerifier.INSTANCE;
SSLConnectionSocketFactory sslFactory = new SSLConnectionSocketFactory(sslContext, hostnameVerifier);
Registry socketFactoryRegistry = RegistryBuilder.create()
.register("http", PlainConnectionSocketFactory.getSocketFactory())
.register("https", sslFactory)
.build();
PoolingHttpClientConnectionManager connMgr = new PoolingHttpClientConnectionManager( socketFactoryRegistry);
connMgr.setMaxTotal(maxTotalConnections);
connMgr.setDefaultMaxPerRoute((connMgr.getMaxTotal()));
HttpClientBuilder builder = HttpClients.custom()
.setDefaultRequestConfig(requestConfig)
.setSslcontext(sslContext)
.setConnectionManager(connMgr)
.setRetryHandler(retryHandler);
this.httpClient = builder.build();
}catch (Exception e){
e.printStackTrace();
}
}
public HttpClient getHttpClient(){
return this.httpClient;
}
public void destroy(){
if(this.httpClient != null){
try{
this.httpClient.close();
this.httpClient = null;
}catch (Exception e){
e.printStackTrace();
}
}
}
}
when I use this class to send post request. something strange happened:
the first time, I send a post request to the server, it's ok
after a minutes, I send a same request to the server, it's ok too.
but after a few minutes, I send a same request, something wrong:
java.net.SocketException: Connection reset by peer: socket write error
at java.net.SocketOutputStream.socketWrite0(Native Method)
at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:92)
at java.net.SocketOutputStream.write(SocketOutputStream.java:136)
at org.apache.http.impl.conn.LoggingOutputStream.write(LoggingOutputStream.java:77)
at org.apache.http.impl.io.SessionOutputBufferImpl.streamWrite(SessionOutputBufferImpl.java:126)
at org.apache.http.impl.io.SessionOutputBufferImpl.flushBuffer(SessionOutputBufferImpl.java:138)
at org.apache.http.impl.io.SessionOutputBufferImpl.flush(SessionOutputBufferImpl.java:146)
at org.apache.http.impl.BHttpConnectionBase.doFlush(BHttpConnectionBase.java:175)
at org.apache.ht 
