HTTP请求类

package com.paytest.util;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLEncoder;
import java.util.List;
import java.util.Map;

public class HttpRequest {
    /**
     * 向指定URL发送GET方法的请求
     * 
     * @param url
     *            发送请求的URL
     * @param param
     *            请求参数，请求参数应该是 name1=value1&name2=value2 的形式。
     * @return URL 所代表远程资源的响应结果
     */
    public static String sendGet(String url, String param) {
        String result = "";
        BufferedReader in = null;
        try {
            String urlNameString = url + "?" + param;
            URL realUrl = new URL(urlNameString);
            // 打开和URL之间的连接
            URLConnection connection = realUrl.openConnection();
            // 设置通用的请求属性
            /**
             * application/x-javascript text/xml->xml数据
             * application/x-javascript->json对象 
             * application/x-www-form-urlencoded->表单数据 
             * application/json;charset=utf-8 -> json数据 
             * */
            connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded"); 
            connection.setRequestProperty("accept", "*/*");
            connection.setRequestProperty("connection", "Keep-Alive");
            connection.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
            // 建立实际的连接
            connection.connect();
            // 获取所有响应头字段
            Map<String, List<String>> map = connection.getHeaderFields();
            // 遍历所有的响应头字段
//            for (String key : map.keySet()) {
//                System.out.println(key + "--->" + map.get(key));
//            }
            // 定义 BufferedReader输入流来读取URL的响应
            in = new BufferedReader(new InputStreamReader(connection.getInputStream(), "utf-8"));
            String line;
            while ((line = in.readLine()) != null) {
                result += line;
            }
        } catch (Exception e) {
            System.out.println("发送GET请求出现异常！" + e);
            e.printStackTrace();
            result="IO_EXCEPTION";
        }
        // 使用finally块来关闭输入流
        finally {
            try {
                if (in != null) {
                    in.close();
                }
            } catch (Exception e2) {
                e2.printStackTrace();
            }
        }
        return result;
    }

    /**
     * 向指定 URL 发送POST方法的请求
     * 
     * @param url
     *            发送请求的 URL
     * @param param
     *            请求参数，请求参数应该是 name1=value1&name2=value2 的形式。
     * @return 所代表远程资源的响应结果
     */
    public static String sendPost(String url, String param) {
        PrintWriter out = null;
        BufferedReader in = null;
        String result = "";
        try {
            URL realUrl = new URL(url);
            // 打开和URL之间的连接
            URLConnection conn = realUrl.openConnection();
            // 设置通用的请求属性
            /**
             * application/x-javascript text/xml->xml数据
             * application/x-javascript->json对象 
             * application/x-www-form-urlencoded->表单数据(key=value&key=value...形式的数据)
             * application/json;charset=utf-8 -> json数据 
             * */
            conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
            conn.setRequestProperty("accept", "*/*");
            conn.setRequestProperty("connection", "Keep-Alive");
            conn.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");

            // 发送POST请求必须设置如下两行
            conn.setDoOutput(true);
            conn.setDoInput(true);
            // 获取URLConnection对象对应的输出流
            out = new PrintWriter(conn.getOutputStream());
            // 发送请求参数
            out.print(param);
            // flush输出流的缓冲
            out.flush();
            // 定义BufferedReader输入流来读取URL的响应
            in = new BufferedReader(new InputStreamReader(conn.getInputStream(), "utf-8"));
            String line;
            while ((line = in.readLine()) != null) {
                result += line;
            }
        } catch (Exception e) {
            System.out.println("发送 POST 请求出现异常！" + e);
            e.printStackTrace();
        }
        // 使用finally块来关闭输出流、输入流
        finally {
            try {
                if (out != null) {
                    out.close();
                }
                if (in != null) {
                    in.close();
                }
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }
        return result;
    }

    public static void main(String[] args) throws UnsupportedEncodingException {
        String s="年后FDSA你好啊";
        //String string = URLEncoder.encode(s, "utf-8");
        String string = URLEncoder.encode(s, "gbk");
        System.out.println(string);
        String sr = HttpRequest.sendGet("https://127.0.0.1/pay/queryOrder", "cpid=weixing&cppwd=654321&phone=13293787666&spnumber=&msgcont="+string+"&extend=01234");
        System.out.println(sr);
    }
}