分享一个简单的HttpClient的例子

在平时的工作中，经常会使用Http去访问其他系统，此时一个Http的工具类就显得非常重要了。给大家分享一个简单的HttpClient的工具类，以备不时之需。

主要包括POST请求、GET请求和如何发送XML数据。

依赖的jar包如下：

<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.3.6</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpcore</artifactId>
<version>4.3.3</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>fluent-hc</artifactId>
<pre name="code" class="html"><pre name="code" class="html"><pre name="code" class="html">     <version>4.3.6</version>
</dependency>
<dependency>
<groupId>dom4j</groupId>
<artifactId>dom4j</artifactId>
<version>1.6.1</version>
</dependency>

import java.io.IOException;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;

import org.apache.http.HttpEntity;
import org.apache.http.HttpStatus;
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.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;
import org.dom4j.Document;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;

public class HttpClientManager {
private static int connectionTimeout = 1000;// 连接超时时间,毫秒
private static int soTimeout = 30000;// 读取数据超时时间，毫秒
/** HttpClient对象 */
private static CloseableHttpClient httpclient = HttpClients.
custom().disableAutomaticRetries().build();
/*** 超时设置 ****/
private static RequestConfig requestConfig = RequestConfig.custom()
.setSocketTimeout(soTimeout)
.setConnectTimeout(connectionTimeout)
.build();//设置请求和传输超时时间
/**
* 根据给定的URL地址和参数字符串，以Get方法调用，如果成功返回true，如果失败返回false
*
* @param url
*            String url地址，不含参数
* @param param
*            String 参数字符串，例如：a=1&b=2&c=3
*/
public String executeGetMethod(String url, String param) {
String strResult = "";
StringBuffer serverURL = new StringBuffer(url);
if (param != null && param.length() > 0) {
serverURL.append("?");
serverURL.append(param);
}
HttpGet httpget = new HttpGet(serverURL.toString());
httpget.setConfig(requestConfig);
CloseableHttpResponse response=null;
try {
response = httpclient.execute(httpget);
HttpEntity entity = response.getEntity();
int iGetResultCode = response.getStatusLine().getStatusCode();
if (iGetResultCode >= 200 && iGetResultCode < 303) {
strResult = EntityUtils.toString(entity);
} else if (iGetResultCode >= 400 && iGetResultCode < 500) {
strResult = "请求的目标地址不存在：" + iGetResultCode;
} else {
strResult = "请求错误：" + iGetResultCode;
}
} catch (Exception ex) {
ex.printStackTrace();
} finally {
try {
if(response !=null){
response.close();
}
} catch (Exception e) {
e.printStackTrace();
}
}
return strResult;
}

/**
* 根据给定的URL地址和参数字符串，以Get方法调用，如果成功返回true，如果失败返回false
*
* @param url
*            String url地址，不含参数
* @param param
*            Map<String, Object> 参数字表单
* @return boolean true－成功，false失败，如果返回成功可以getStrGetResponseBody()
*         获取返回内容字符串，如果失败，则可访问getErrorInfo()获取错误提示。
*/
public String executePostMethod(String strURL, Map<String, String> param) {
String strResult = "";
HttpPost post = new HttpPost(strURL);
post.setConfig(requestConfig);
List<BasicNameValuePair> paraList = new ArrayList<BasicNameValuePair>(param.size());
for (Entry<String, String> pEntry : param.entrySet()) {
if(null != pEntry.getValue()){
BasicNameValuePair nv = new BasicNameValuePair(pEntry.getKey(), pEntry.getValue());
paraList.add(nv);
}
}
//使用UTF-8
UrlEncodedFormEntity entity = new UrlEncodedFormEntity(paraList,Charset.forName("utf-8"));
post.setEntity(entity);
CloseableHttpResponse response=null;
try {
response = httpclient.execute(post);
int iGetResultCode = response.getStatusLine().getStatusCode();
if (HttpStatus.SC_OK == iGetResultCode) {
HttpEntity responseEntity = response.getEntity();
strResult = EntityUtils.toString(responseEntity);
}

} catch (Exception ex) {
ex.printStackTrace();
} finally {
try {
if(response!=null){
response.close();
}
} catch (IOException e) {
}
}
return strResult;
}

/**
* 发送xml数据
* @param strURL
* @param params
* @return
*/
public String postByXml(String strURL,Map<String,String> params) {
String strResult = "";
CloseableHttpResponse response = null;
try {
HttpPost post = new HttpPost(strURL);
post.setConfig(requestConfig);
post.setHeader("Content-Type", "text/xml;charset=utf-8");
String xmlData = convertMap2Xml(params);
StringEntity se = new StringEntity(xmlData);
post.setEntity(se);
response = httpclient.execute(post);
response = httpclient.execute(post);
int iGetResultCode = response.getStatusLine().getStatusCode();
if (HttpStatus.SC_OK == iGetResultCode) {
HttpEntity responseEntity = response.getEntity();
strResult = EntityUtils.toString(responseEntity);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if(response !=null){
response.close();
}
} catch (Exception e) {
e.printStackTrace();
}
}
return strResult;
}
/**
* 将map转换为xml
* @param map
*/
private static String convertMap2Xml(Map<String,String> map) {
Set<Entry<String,String>> entrys = map.entrySet();
Iterator<Entry<String,String>> iter = entrys.iterator();
Document doc = DocumentHelper.createDocument();
Element root = DocumentHelper.createElement("xml");
while(iter.hasNext()) {
Entry<String,String> entry = iter.next();
Element key = DocumentHelper.createElement(entry.getKey());
key.addCDATA(entry.getValue());
root.add(key);
}
doc.add(root);
return doc.asXML();
}
}