模擬HTTP請求獲取返回值

package org.jeecgframework.core.util;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLDecoder;
import java.util.List;
import java.util.Map;

import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.config.RequestConfig;
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.apache.log4j.Logger;

/**
 * @author Link Xue 
 * @version 2017年8月20日 上午11:03:13
 * 模擬HTTP請求獲取返回值
 */
public class HttpRequest {

    private static Logger logger = Logger.getLogger(HttpRequest.class);
    
    /**
     * post請求
     * @param url         url地址
     * @param param     請求參數
     * @param noNeedResponse    不需要返回結果
     * @return
     * @throws IOException 
     * @throws ClientProtocolException 
     */
    public static String httpPost(String url,String param, boolean noNeedResponse) throws ClientProtocolException, IOException{        
        
        url = URLDecoder.decode(url, "UTF-8");
        CloseableHttpClient httpClient = HttpClients.createDefault();
        String result = null;
        HttpPost method = new HttpPost(url);        

        RequestConfig requestConfig = RequestConfig.custom().setSocketTimeout(1000).setConnectTimeout(300).build();//設置請求和傳輸超時時間
        method.setConfig(requestConfig);
        
        if (null != param) {             
            StringEntity entity = new StringEntity(param, "utf-8");
            entity.setContentEncoding("UTF-8");
            entity.setContentType("application/x-www-form-urlencoded");
            method.setEntity(entity);
        }
        
        HttpResponse resultRep = httpClient.execute(method);
        /**請求發送成功，並得到響應**/
        if (resultRep.getStatusLine().getStatusCode() == 200) {
            String str = "";     
            /**讀取服務器返回過來的json字符串數據**/
            str = EntityUtils.toString(resultRep.getEntity());
            if (noNeedResponse) {
                return null;
            }
            /**把json字符串轉換成json對象**/
            //jsonResult = JSONObject.parseObject(str);
            result = str;
        }
        return result;
    }
    
    /**
     * 向指定URL發送GET方法的請求
     * 
     * @param url
     *            發送請求的URL
     * @param param
     *            請求參數，請求參數應該是 name1=value1&name2=value2 的形式。
     * @return URL 所代表遠程資源的響應結果
     */
    public static String sendGet(String url, String param) {
        String result = "";
        BufferedReader in = null;
        try {
            String urlNameString = url + "?" + param;
            URL realUrl = new URL(urlNameString);
            // 打開和URL之間的連接
            URLConnection connection = realUrl.openConnection();
            // 設置通用的請求屬性
            connection.setRequestProperty("accept", "*/*");
            connection.setRequestProperty("connection", "Keep-Alive");
            connection.setRequestProperty("user-agent",
                    "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
            // 建立實際的連接
            connection.connect();
            // 獲取所有響應頭字段
            Map<String, List<String>> map = connection.getHeaderFields();
            // 遍歷所有的響應頭字段
            for (String key : map.keySet()) {
                System.out.println(key + "--->" + map.get(key));
            }
            // 定義 BufferedReader輸入流來讀取URL的響應
            in = new BufferedReader(new InputStreamReader(
                    connection.getInputStream()));
            String line;
            while ((line = in.readLine()) != null) {
                result += line;
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        // 使用finally塊來關閉輸入流
        finally {
            try {
                if (in != null) {
                    in.close();
                }
            } catch (Exception e2) {
                e2.printStackTrace();
            }
        }
        return result;
    }

    /**
     * 向指定 URL 發送POST方法的請求
     * 
     * @param url
     *            發送請求的 URL
     * @param param
     *            請求參數，請求參數應該是 name1=value1&name2=value2 的形式。
     * @return 所代表遠程資源的響應結果
     */
    public static String sendPost(String url, String param) {
        PrintWriter out = null;
        BufferedReader in = null;
        String result = "";
        try {
            URL realUrl = new URL(url);
            // 打開和URL之間的連接
            URLConnection conn = realUrl.openConnection();
            // 設置通用的請求屬性
            conn.setRequestProperty("accept", "*/*");
            conn.setRequestProperty("connection", "Keep-Alive");
            conn.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
            // 發送POST請求必須設置如下兩行
            conn.setDoOutput(true);
            conn.setDoInput(true);
            // 獲取URLConnection對象對應的輸出流
            out = new PrintWriter(conn.getOutputStream());
            // 發送請求參數
            out.print(param);
            // flush輸出流的緩沖
            out.flush();
            // 定義BufferedReader輸入流來讀取URL的響應
            in = new BufferedReader( new InputStreamReader(conn.getInputStream()));
            String line;
            while ((line = in.readLine()) != null) {
                result += line;
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        //使用finally塊來關閉輸出流、輸入流
        finally{
            try{
                if(out!=null){
                    out.close();
                }
                if(in!=null){
                    in.close();
                }
            }catch(IOException ex){
                ex.printStackTrace();
            }
        }
        return result;
    } 
}