HttpURLConnection is used as a tool class for request calling interface without return parameters

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();  

            // Convert the returned input stream into a string   
            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();  
            // Release resources   
            inputStream.close();  
            inputStream = null;  
            httpUrlConn.disconnect();  

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