public class RestUtil {

  //get
  public void getMethod(String url) throws IOException {
    URL restURL = new URL(url);

    HttpURLConnection conn = (HttpURLConnection) restURL.openConnection();

    conn.setRequestMethod("GET"); // POST GET PUT DELETE
    conn.setRequestProperty("Accept", "application/json");

    BufferedReader br = new BufferedReader(new InputStreamReader(conn.getInputStream()));
    String line;
    while((line = br.readLine()) != null ){
      System.out.println(line);
    }

    br.close();
  }

  //post 
  public void postMethod(String url, String query) throws IOException {
    URL restURL = new URL(url);

    HttpURLConnection conn = (HttpURLConnection) restURL.openConnection();
    conn.setRequestMethod("POST");
    conn.setRequestProperty("Content-Type", "application/json");
    conn.setDoOutput(true);

    PrintStream ps = new PrintStream(conn.getOutputStream());
    ps.print(query);
    ps.close();

    BufferedReader br = new BufferedReader(new InputStreamReader(conn.getInputStream()));
    String line;
    while((line = br.readLine()) != null ){
      System.out.println(line);
    }

    br.close();
  }

  public static void main(String[] args) {
    RestUtil restUtil = new RestUtil();
    try {
      restUtil.getMethod("http://www.baidu.com");

      String url = "";
      String query = ""; //json格式
      restUtil.postMethod(url, query);

    }catch (Exception e){
      System.out.println(e.getMessage());
    }
  }

}