基於HttpURLConnection的接口調用，支持GET&POST

單位要做一個多級部署平台，大概意思就是一級系統可以監控下屬地域的數據也可管理本地的數據。之前做短信貓用過httpClient請求，與此大同小異。封裝了一個兩種請求方式的工具類。

package com.subordinate.util;

import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;

/**
 * 接口調用工具類
 *     目前支持 GET POST請求兩種方式
 * 
 * @author Together
 *
 *@date 2018年4月17日
 */
public class HttpURLConnectionUtil {

    
    /**
     * get請求
     * 
     * @param url
     * @param param
     * @return
     */
    public static String get(String url,Map<String, Object> param) {
        StringBuilder builder=new StringBuilder();
        try {
            StringBuilder params=new StringBuilder();
            for(Entry<String, Object> entry:param.entrySet()){
                params.append(entry.getKey());
                params.append("=");
                params.append(entry.getValue().toString());
                params.append("&");
            }
            if(params.length()>0){
                params.deleteCharAt(params.lastIndexOf("&"));
            }
            URL restServiceURL = new URL(url+(params.length()>0 ? "?"+params.toString() : ""));
            HttpURLConnection httpConnection = (HttpURLConnection) restServiceURL.openConnection();
            httpConnection.setRequestMethod("GET");
            httpConnection.setRequestProperty("Accept", "application/json");
            if (httpConnection.getResponseCode() != 200) {
                throw new RuntimeException("HTTP GET Request Failed with Error code : "
                              + httpConnection.getResponseCode());
         }
            InputStream inStrm = httpConnection.getInputStream();
            byte []b=new byte[1024];
            int length=-1;
            while((length=inStrm.read(b))!=-1){
                builder.append(new String(b,0,length));
            }
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return builder.toString();
    }
    /**
     * post    請求
     * 
     * @param url
     * @param param
     * @return
     */
    public static String post(String url,Map<String, Object> param) {
        StringBuilder builder=new StringBuilder();
        try {
            StringBuilder params=new StringBuilder();
            for(Entry<String, Object> entry:param.entrySet()){
                params.append(entry.getKey());
                params.append("=");
                params.append(entry.getValue().toString());
                params.append("&");
            }
            if(params.length()>0){
                params.deleteCharAt(params.lastIndexOf("&"));
            }
            URL restServiceURL = new URL(url+(params.length()>0 ? "?"+params.toString() : ""));
            HttpURLConnection httpConnection = (HttpURLConnection) restServiceURL.openConnection();
            httpConnection.setRequestMethod("POST");
            httpConnection.setRequestProperty("Accept", "application/json");
            // 設置是否從httpUrlConnection讀入，默認情況下是true;    
            httpConnection.setDoInput(true);    
            // Post 請求不能使用緩存    
            httpConnection.setUseCaches(false); 
            if (httpConnection.getResponseCode() != 200) {
                throw new RuntimeException("HTTP POST Request Failed with Error code : "
                              + httpConnection.getResponseCode());
         }
            InputStream inStrm = httpConnection.getInputStream();
            byte []b=new byte[1024];
            int length=-1;
            while((length=inStrm.read(b))!=-1){
                builder.append(new String(b,0,length));
            }
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return builder.toString();
    }
    
    public static void main(String[] args) {
        String urlString="http://localhost:8080/vms/subordinate/testController/test";
        Map<String, Object> param=new HashMap<String, Object>();
        param.put("userId", "123456");
        param.put("pa", "hello");
        HttpURLConnectionUtil.get(urlString, param);
        HttpURLConnectionUtil.post(urlString, param);
    }
}