Java Http 请求

package zr.weixin.com.utils;

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStream;

import java.io.InputStreamReader;

import java.io.OutputStream;

import java.io.OutputStreamWriter;

import java.net.HttpURLConnection;

import java.net.MalformedURLException;

import java.net.URL;

import java.util.Map;

import java.util.Map.Entry;

import com.alibaba.fastjson.JSON;

import com.alibaba.fastjson.JSONObject;

public class HttpClientHelper {

    /**

     * http请求（GET）

     */

    public static String sendGet(String urlParam, Map<String, Object> params, String charset) {

        StringBuffer resultBuffer = null;

        // 拼接字段

        StringBuffer sbParams = new StringBuffer();

        if (params != null && params.size() > 0) {

            for (Entry<String, Object> entry : params.entrySet()) {

                sbParams.append(entry.getKey());

                sbParams.append("=");

                sbParams.append(entry.getValue());

                sbParams.append("&");

            }

        }

        HttpURLConnection con = null;

        BufferedReader br = null;

        // url与拼接好的字段连接在一起

        try {

            URL url = null;

            if (sbParams != null && sbParams.length() > 0) {

                url = new URL(urlParam + "?" + sbParams.substring(0, sbParams.length() - 1));

            } else {

                url = new URL(urlParam);

            }

            // 打开连接

            con = (HttpURLConnection) url.openConnection();

            // 设置请求头

            con.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");

            // 开启连接

            con.connect();

            // 将返回的数据转成StringBuffer对象

            resultBuffer = new StringBuffer();

            br = new BufferedReader(new InputStreamReader(con.getInputStream(), charset));

            String temp;

            while ((temp = br.readLine()) != null) {

                resultBuffer.append(temp);

            }

        } catch (Exception e) {

            throw new RuntimeException(e);

        } finally {

            if (br != null) {

                try {

                    br.close();

                } catch (IOException e) {

                    br = null;

                    throw new RuntimeException(e);

                } finally {

                    if (con != null) {

                        con.disconnect();

                        con = null;

                    }

                }

            }

        }

        return resultBuffer.toString();

    }  

    /**

     * http请求（POST）

     * @param urlParam

     * @param params

     * @param charset

     * @return

     */

    public static String sendPost(String urlParam,Map<String, Object> params,String charset){

        StringBuffer resultBuffer = null;

        // 拼接字段

        StringBuffer sbParams = new StringBuffer();

        if (params != null && params.size() > 0) {

            for (Entry<String, Object> e : params.entrySet()) {

                sbParams.append(e.getKey());

                sbParams.append("=");

                sbParams.append(e.getValue());

                sbParams.append("&");

            }

        }

        HttpURLConnection con = null;

        OutputStreamWriter osw = null;

        BufferedReader br = null;

        // 设置请求相应的参数

        try {

            URL url = new URL(urlParam);

            con = (HttpURLConnection) url.openConnection();

            con.setRequestMethod("POST");

            con.setDoOutput(true);

            con.setDoInput(true);

            con.setUseCaches(false);

            con.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");

            if (sbParams != null && sbParams.length() > 0) {

                osw = new OutputStreamWriter(con.getOutputStream(), charset);

                osw.write(sbParams.substring(0, sbParams.length() - 1));

                osw.flush();

            }

            // 将返回的数据转成StringBuffer对象

            resultBuffer = new StringBuffer();

            int contentLength = Integer.parseInt(con.getHeaderField("Content-Length"));

            if (contentLength > 0) {

                br = new BufferedReader(new InputStreamReader(con.getInputStream(), charset));

                String temp;

                while ((temp = br.readLine()) != null) {

                    resultBuffer.append(temp);

                }

            }

        } catch (Exception e) {

            throw new RuntimeException(e);

        } finally {

            if (osw != null) {

                try {

                    osw.close();

                } catch (IOException e) {

                    osw = null;

                    throw new RuntimeException(e);

                } finally {

                    if (con != null) {

                        con.disconnect();

                        con = null;

                    }

                }

            }

            if (br != null) {

                try {

                    br.close();

                } catch (IOException e) {

                    br = null;

                    throw new RuntimeException(e);

                } finally {

                    if (con != null) {

                        con.disconnect();

                        con = null;

                    }

                }

            }

        }

        return resultBuffer.toString();

    }

    /**

     * post请求

     * @param urlParam

     * @param Json

     * @param charset

     * @return

     */

    public static String sendPost(String urlParam,String Json, String charset) {

        StringBuffer resultBuffer = null;

        HttpURLConnection con = null;

        OutputStreamWriter osw = null;

        BufferedReader br = null;

        // 发送请求

        try {

            URL url = new URL(urlParam);

            con = (HttpURLConnection) url.openConnection();

            con.setRequestMethod("POST");

            con.setDoOutput(true);

            con.setDoInput(true);

            con.setUseCaches(false);

            con.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");

            if (Json!=null&&Json.length()>0) {

                osw = new OutputStreamWriter(con.getOutputStream(), charset);

                osw.write(Json);

                osw.flush();

            }

            // 读取返回内容

            resultBuffer = new StringBuffer();

            int contentLength = Integer.parseInt(con.getHeaderField("Content-Length"));

            if (contentLength > 0) {

                br = new BufferedReader(new InputStreamReader(con.getInputStream(), charset));

                String temp;

                while ((temp = br.readLine()) != null) {

                    resultBuffer.append(temp);

                }

            }

        } catch (Exception e) {

            throw new RuntimeException(e);

        } finally {

            if (osw != null) {

                try {

                    osw.close();

                } catch (IOException e) {

                    osw = null;

                    throw new RuntimeException(e);

                } finally {

                    if (con != null) {

                        con.disconnect();

                        con = null;

                    }

                }

            }

            if (br != null) {

                try {

                    br.close();

                } catch (IOException e) {

                    br = null;

                    throw new RuntimeException(e);

                } finally {

                    if (con != null) {

                        con.disconnect();

                        con = null;

                    }

                }

            }

        }  

        return resultBuffer.toString();

    }

}