Java使用httpclient封装post请求和get请求

package com.marco.common;
 
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.URI;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
 
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.NameValuePair;
import org.apache.http.StatusLine;
import org.apache.http.client.HttpClient;
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.DefaultHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.protocol.HTTP;
import org.apache.http.util.EntityUtils;
import org.apache.log4j.Logger;
 
/**
 * @author 马弦
 * @date 2017年10月23日 下午2:49
 * HttpClient工具类
 */
public class HttpUtil {
	
	private static Logger logger = Logger.getLogger(HttpUtil.class);
 
	/**
	 * get请求
	 * @return
	 */
	public static String doGet(String url) {
        try {
        	HttpClient client = new DefaultHttpClient();
            //发送get请求
            HttpGet request = new HttpGet(url);
            HttpResponse response = client.execute(request);
 
            /**请求发送成功，并得到响应**/
            if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
                /**读取服务器返回过来的json字符串数据**/
                String strResult = EntityUtils.toString(response.getEntity());
                
                return strResult;
            }
        } 
        catch (IOException e) {
        	e.printStackTrace();
        }
        
        return null;
	}
	
	/**
	 * post请求(用于key-value格式的参数)
	 * @param url
	 * @param params
	 * @return
	 */
	public static String doPost(String url, Map params){
		
		BufferedReader in = null;  
        try {  
            // 定义HttpClient  
            HttpClient client = new DefaultHttpClient();  
            // 实例化HTTP方法  
            HttpPost request = new HttpPost();  
            request.setURI(new URI(url));
            
            //设置参数
            List<NameValuePair> nvps = new ArrayList<NameValuePair>(); 
            for (Iterator iter = params.keySet().iterator(); iter.hasNext();) {
    			String name = (String) iter.next();
    			String value = String.valueOf(params.get(name));
    			nvps.add(new BasicNameValuePair(name, value));
    			
    			//System.out.println(name +"-"+value);
    		}
            request.setEntity(new UrlEncodedFormEntity(nvps,HTTP.UTF_8));
            
            HttpResponse response = client.execute(request);  
            int code = response.getStatusLine().getStatusCode();
            if(code == 200){	//请求成功
            	in = new BufferedReader(new InputStreamReader(response.getEntity()  
                        .getContent(),"utf-8"));
                StringBuffer sb = new StringBuffer("");  
                String line = "";  
                String NL = System.getProperty("line.separator");  
                while ((line = in.readLine()) != null) {  
                    sb.append(line + NL);  
                }
                
                in.close();  
                
                return sb.toString();
            }
            else{	//
            	System.out.println("状态码：" + code);
            	return null;
            }
        }
        catch(Exception e){
        	e.printStackTrace();
        	
        	return null;
        }
	}
	
	/**
	 * post请求（用于请求json格式的参数）
	 * @param url
	 * @param params
	 * @return
	 */
	public static String doPost(String url, String params) throws Exception {
		
		CloseableHttpClient httpclient = HttpClients.createDefault();
		HttpPost httpPost = new HttpPost(url);// 创建httpPost   
    	httpPost.setHeader("Accept", "application/json"); 
    	httpPost.setHeader("Content-Type", "application/json");
    	String charSet = "UTF-8";
    	StringEntity entity = new StringEntity(params, charSet);
    	httpPost.setEntity(entity);        
        CloseableHttpResponse response = null;
        
        try {
        	
        	response = httpclient.execute(httpPost);
            StatusLine status = response.getStatusLine();
            int state = status.getStatusCode();
            if (state == HttpStatus.SC_OK) {
            	HttpEntity responseEntity = response.getEntity();
            	String jsonString = EntityUtils.toString(responseEntity);
            	return jsonString;
            }
            else{
				 logger.error("请求返回:"+state+"("+url+")");
			}
        }
        finally {
            if (response != null) {
                try {
                    response.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            try {
				httpclient.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
        }
        return null;
	}
	
}

上述方法已过时， 下边为新的封装类

/**
 * <p>Title: HttpUtil.java</p> 
 * @author xiatian
 * @date 2019年3月4日
 */
package com.weixin.util;

import java.io.IOException;
import java.net.URLEncoder;
import java.util.Iterator;
import java.util.Map;

import org.apache.http.HttpEntity;
import org.apache.http.HttpStatus;
import org.apache.http.client.config.RequestConfig;
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.util.EntityUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * @author xl
 *
 */
public class HttpUtil {

	private static Logger logger = LoggerFactory.getLogger(HttpUtil.class);

	private static final CloseableHttpClient httpClient;
	static {
		httpClient = HttpClients.createDefault();
	}

	/**
	 * get请求
	 * 
	 * @return
	 */
	public static String doGet(String url) {
		CloseableHttpResponse response = null;
		try {
			// 发送get请求
			HttpGet httpGet = new HttpGet(url);
			// 配置请求参数
			RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(5000)
					.setConnectionRequestTimeout(1000).setSocketTimeout(6000).build();
			httpGet.setConfig(requestConfig);
			// 执行请求
			response = httpClient.execute(httpGet);
			// 建立的http连接，仍旧被response保持着，允许我们从网络socket中获取返回的数据
			// 为了释放资源，我们必须手动消耗掉response或者取消连接（使用CloseableHttpResponse类的close方法）
			/** 请求发送成功，并得到响应 **/
			if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
				/** 读取服务器返回过来的json字符串数据 **/
				HttpEntity entity = response.getEntity();
				if (entity != null) {
					String strResult = EntityUtils.toString(entity, "UTF-8");
					/** 消耗掉entity对象 **/
					EntityUtils.consume(entity);
					return strResult;
				}
			}
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			if (response != null) {
				try {
					response.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}
		return null;
	}

	/**
	 * post请求(请求参数是 name1=value1&name2=value2 的形式)
	 * 
	 * @param url
	 * @param params
	 * @return
	 */
	public static String doPost(String url, String params) {
		// 创建httpPost
		HttpPost httpPost = new HttpPost(url);
		httpPost.setHeader("Accept", "*/*");
		httpPost.setHeader("Accept-Charset", "UTF-8");
		httpPost.setHeader("Content-Type", "application/x-www-form-urlencoded; charset=UTF-8");
		StringEntity entity = new StringEntity(params, "UTF-8");
		httpPost.setEntity(entity);
		// 配置请求参数
		RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(5000)
				.setConnectionRequestTimeout(1000).setSocketTimeout(6000).build();
		httpPost.setConfig(requestConfig);
		// 执行请求
		CloseableHttpResponse response = null;
		try {
			response = httpClient.execute(httpPost);
			if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
				HttpEntity responseEntity = response.getEntity();
				if (responseEntity != null) {
					String jsonString = EntityUtils.toString(responseEntity, "UTF-8");
					/** 消耗掉entity对象 **/
					EntityUtils.consume(responseEntity);
					return jsonString;
				}
			}
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			if (response != null) {
				try {
					response.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}
		return null;
	}

	/**
	 * post请求（用于请求json格式的参数）
	 * 
	 * @param url
	 * @param params
	 * @return
	 */
	public static String doJsonPost(String url, String params) throws Exception {
		// 创建httpPost
		HttpPost httpPost = new HttpPost(url);
		httpPost.setHeader("Accept", "application/json");
		httpPost.setHeader("Content-Type", "application/json");
		StringEntity entity = new StringEntity(params, "UTF-8");
		httpPost.setEntity(entity);
		// 配置请求参数
		RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(5000)
				.setConnectionRequestTimeout(1000).setSocketTimeout(6000).build();
		httpPost.setConfig(requestConfig);
		// 执行请求
		CloseableHttpResponse response = null;
		try {
			response = httpClient.execute(httpPost);
			if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
				HttpEntity responseEntity = response.getEntity();
				if (responseEntity != null) {
					String jsonString = EntityUtils.toString(responseEntity, "UTF-8");
					/** 消耗掉entity对象 **/
					EntityUtils.consume(responseEntity);
					return jsonString;
				}
			}
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			if (response != null) {
				try {
					response.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}
		return null;
	}

	/**
	 * 将map对象转换为URL参数格式
	 * 
	 * @param params
	 * @return
	 */
	public static String buildParam(Map<String, Object> params) {
		if (params.isEmpty()) {
			return "";
		}
		StringBuilder param = new StringBuilder();
		Iterator<String> keyItor = params.keySet().iterator();
		try {
			while (keyItor.hasNext()) {
				String key = keyItor.next();
				Object o = params.get(key);
				if (o == null) {
					param.append(key + "=&");
				} else {
					param.append(key + "=" + URLEncoder.encode(String.valueOf(o), "UTF-8") + "&");
				}
			}
			if (param.length() != 0) {
				param.deleteCharAt(param.length() - 1);
			}
		} catch (Exception ex) {
			logger.error(ex.getMessage());
		}
		return param.toString();
	}

}

完！！！