Java模拟http请求调用远程接口工具类

 package ln;

 import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.io.PrintWriter;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;

 /**
  * 用于模拟HTTP请求中GET/POST方式
  * @author landa
  *
  */
 public class HttpUtils {
     /**
      * 发送GET请求
      *
      * @param url
      *            目的地址
      * @param parameters
      *            请求参数，Map类型。
      * @return 远程响应结果
      */
     public static String sendGet(String url, Map<String, String> parameters) {
         String result="";
         BufferedReader in = null;// 读取响应输入流
         StringBuffer sb = new StringBuffer();// 存储参数
         String params = "";// 编码之后的参数
         try {
             // 编码请求参数
             if(parameters.size()==1){
                 for(String name:parameters.keySet()){
                     sb.append(name).append("=").append(
                             java.net.URLEncoder.encode(parameters.get(name),
                             "UTF-8"));
                 }
                 params=sb.toString();
             }else{
                 for (String name : parameters.keySet()) {
                     sb.append(name).append("=").append(
                             java.net.URLEncoder.encode(parameters.get(name),
                                     "UTF-8")).append("&");
                 }
                 String temp_params = sb.toString();
                 params = temp_params.substring(0, temp_params.length() - 1);
             }
             String full_url = url + "?" + params;
             System.out.println(full_url);
             // 创建URL对象
             java.net.URL connURL = new java.net.URL(full_url);
             // 打开URL连接
             java.net.HttpURLConnection httpConn = (java.net.HttpURLConnection) connURL
                     .openConnection();
             // 设置通用属性
             httpConn.setRequestProperty("Accept", "*/*");
             httpConn.setRequestProperty("Connection", "Keep-Alive");
             httpConn.setRequestProperty("User-Agent",
                     "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1)");
             // 建立实际的连接
             httpConn.connect();
             // 响应头部获取
             Map<String, List<String>> headers = httpConn.getHeaderFields();
             // 遍历所有的响应头字段
             for (String key : headers.keySet()) {
                 System.out.println(key + "\t：\t" + headers.get(key));
             }
             // 定义BufferedReader输入流来读取URL的响应,并设置编码方式
             in = new BufferedReader(new InputStreamReader(httpConn
                     .getInputStream(), "UTF-8"));
             String line;
             // 读取返回的内容
             while ((line = in.readLine()) != null) {
                 result += line;
             }
         } catch (Exception e) {
             e.printStackTrace();
         }finally{
             try {
                 if (in != null) {
                     in.close();
                 }
             } catch (IOException ex) {
                 ex.printStackTrace();
             }
         }
         return result ;
     }  

     /**
      * 发送POST请求
      *
      * @param url
      *            目的地址
      * @param parameters
      *            请求参数，Map类型。
      * @return 远程响应结果
      */
     public static String sendPost(String url, Map<String, String> parameters) {
         String result = "";// 返回的结果
         BufferedReader in = null;// 读取响应输入流
         PrintWriter out = null;
         StringBuffer sb = new StringBuffer();// 处理请求参数
         String params = "";// 编码之后的参数
         try {
             // 编码请求参数
             if (parameters.size() == 1) {
                 for (String name : parameters.keySet()) {
                     sb.append(name).append("=").append(
                             java.net.URLEncoder.encode(parameters.get(name),
                                     "UTF-8"));
                 }
                 params = sb.toString();
             } else {
                 for (String name : parameters.keySet()) {
                     sb.append(name).append("=").append(
                             java.net.URLEncoder.encode(parameters.get(name),
                                     "UTF-8")).append("&");
                 }
                 String temp_params = sb.toString();
                 params = temp_params.substring(0, temp_params.length() - 1);
             }
             // 创建URL对象
             java.net.URL connURL = new java.net.URL(url);
             // 打开URL连接
             java.net.HttpURLConnection httpConn = (java.net.HttpURLConnection) connURL
                     .openConnection();
             // 设置通用属性
             httpConn.setRequestProperty("Accept", "*/*");
             httpConn.setRequestProperty("Connection", "Keep-Alive");
             httpConn.setRequestProperty("User-Agent",
                     "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1)");
             // 设置POST方式
             httpConn.setDoInput(true);
             httpConn.setDoOutput(true);
             // 获取HttpURLConnection对象对应的输出流
             out = new PrintWriter(httpConn.getOutputStream());
             // 发送请求参数
             out.write(params);
             // flush输出流的缓冲
             out.flush();
             // 定义BufferedReader输入流来读取URL的响应，设置编码方式
             in = new BufferedReader(new InputStreamReader(httpConn
                     .getInputStream(), "UTF-8"));
             String line;
             // 读取返回的内容
             while ((line = in.readLine()) != null) {
                 result += line;
             }
         } catch (Exception e) {
             e.printStackTrace();
         } finally {
             try {
                 if (out != null) {
                     out.close();
                 }
                 if (in != null) {
                     in.close();
                 }
             } catch (IOException ex) {
                 ex.printStackTrace();
             }
         }
         return result;
     }  

     /**
      * 主函数，测试请求
      *
      * @param args
      */
     public static void main(String[] args) {
         Map<String, String> parameters = new HashMap<String, String>();
         parameters.put("name", "sarin");
         String result =sendGet("http://www.baidu.com", parameters);
         System.out.println(result);
     }
 }