Apache HttpClient组件封装工具类

package com.mengyao.spider.utils;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;

import org.apache.http.Header;
import org.apache.http.HttpEntity;
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.client.methods.HttpRequestBase;
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.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;
import org.apache.http.NameValuePair;

/**
* 依赖于Apache httpcomponents项目下的HttpClient组件中的httpclient-4.4.jar、httpcore-4.4.jar、commons-logging-1.2.jar
* @author mengyao
*
*/
public class HttpUtil {

/**
* 创建httpClient实例
* @return
*/
public CloseableHttpClient getHttpClient() {
HttpClientBuilder builder = HttpClients.custom();
CloseableHttpClient client = builder.build();
return client;
}

/**
* 构造Post请求
* @param url
* @param params
* @param encoding
* @return
* @throws Exception
*/
public HttpPost getHttpPost(String url, Map<String, String> params, String encoding) throws Exception{
HttpPost post = new HttpPost(url);
List<NameValuePair> parammeters = new ArrayList<NameValuePair>();
Iterator<Entry<String, String>> iterator = params.entrySet().iterator();
while(iterator.hasNext()){
Entry<String, String> next = iterator.next();
parammeters.add(new BasicNameValuePair(next.getKey(), next.getValue()));
}
UrlEncodedFormEntity urlEncodedFormEntity = new UrlEncodedFormEntity(parammeters, encoding);
post.setEntity(urlEncodedFormEntity);

return post;
}

/**
* 构造Get请求
* @param url
* @return
*/
public HttpGet getHttpGet(String url){
HttpGet get = new HttpGet(url);
return get;
}

/**
* 为Post或Get请求设置Http请求头参数
* @param postAndGet
* @param headers
* @return
*/
public HttpRequestBase setHeader(HttpRequestBase postAndGet, Map<String, String> headers){
Iterator<Entry<String, String>> iterator = headers.entrySet().iterator();
while(iterator.hasNext()){
Entry<String, String> next = iterator.next();
postAndGet.addHeader(next.getKey(), next.getValue());
}
return postAndGet;
}

/**
* 获取Http响应中的响应头参数
* @param response
* @return
*/
public Map<String, String> getHeader(CloseableHttpResponse response){
Map<String, String> headers = new HashMap<String, String>();
Header[] allHeaders = response.getAllHeaders();
for (Header header : allHeaders) {
headers.put(header.getName(), header.getValue());
}
return headers;
}

/**
* 获取Http响应中的原生数据
* @param entity
* @param consume
* @return
* @throws Exception
*/
public String getRawContent(HttpEntity entity, boolean consume) throws Exception{
String rawCtx = EntityUtils.toString(entity);
if (consume) {
EntityUtils.consume(entity);
}
return rawCtx;
}

/**
* 释放Http连接
* @param client
* @throws Exception
*/
public void clean(CloseableHttpClient client) throws Exception{
client.close();
}

public static void main(String[] args) throws Exception {
HttpUtil httpUtil = new HttpUtil();
/************************************* 创建HttpGet请求Begin ***********************************/
//获取Http实例
CloseableHttpClient httpClient = httpUtil.getHttpClient();
//创建HttpGet请求
HttpGet httpGet = httpUtil.getHttpGet("http://www.jd.com");
//设置HttpGet请求头参数
Map<String, String> headers = new HashMap<String, String>();
headers.put("User-Agent", "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:39.0) Gecko/20100101 Firefox/39.0");
httpUtil.setHeader(httpGet, headers);
//提交HttpGet请求，同时获取Http响应
CloseableHttpResponse response = httpClient.execute(httpGet);
//获取Http的响应头参数
Map<String, String> header = httpUtil.getHeader(response);
//获取Http响应中的原生数据内容，同时关闭Http底层连接
String rawContent = httpUtil.getRawContent(response.getEntity(), true);
//释放本次Http请求实例
httpUtil.clean(httpClient);
/************************************* 创建HttpGet请求End ***********************************/

//HttpPost请求与上述代码同理，不做演示
}
}