HttpURLConnection 当作请求调用接口不带返回参数的工具类

package cn.smartercampus.core.util;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;

public class HttpCilent {
    public String httpRequest(String req_url) {
        StringBuffer buffer = new StringBuffer();
        try {
            URL url = new URL(req_url);
            HttpURLConnection httpUrlConn = (HttpURLConnection) url.openConnection();  

            httpUrlConn.setDoOutput(false);
            httpUrlConn.setDoInput(true);
            httpUrlConn.setUseCaches(false);  

            httpUrlConn.setRequestMethod("GET");
            httpUrlConn.connect();  

            // 将返回的输入流转换成字符串
            InputStream inputStream = httpUrlConn.getInputStream();
            InputStreamReader inputStreamReader = new InputStreamReader(inputStream, "utf-8");
            BufferedReader bufferedReader = new BufferedReader(inputStreamReader);  

            String str = null;
            while ((str = bufferedReader.readLine()) != null) {
                buffer.append(str);
            }
            bufferedReader.close();
            inputStreamReader.close();
            // 释放资源
            inputStream.close();
            inputStream = null;
            httpUrlConn.disconnect();  

        } catch (Exception e) {
            System.out.println(e.getStackTrace());
        }
        return buffer.toString();
    }
}