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);

    }

}