Getting servlet: request header data acquisition request

 1 @WebServlet("/RequestDemo2")
 2 public class RequestDemo2 extends HttpServlet {
 3     protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
 4 
 5     }
 6 
 7     protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
 8         //演示获取请求头数据
 9 
10         //1.获取所有请求头名称
11         Enumeration<String> headerNames =request.getHeaderNames ();
 12 is          // 2. traverse 
13 is          the while (headerNames.hasMoreElements ()) {
 14              String name = headerNames.nextElement ();
 15              // get the value of the first request by name request header 
16              String value = Request .getHeader (name);
 . 17              System.out.println (name + "----" + value);
 18 is          }
 . 19      }
 20 is }

 

 1 @WebServlet("/RequestDemo3")
 2 public class RequestDemo3 extends HttpServlet {
 3     protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
 4 
 5     }
 6 
 7     protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
 8         //演示获取请求头数据：user-agent
 9         String agent = request.getHeader("user-agent");
10         //The browser version of the agent sentence of 
11          IF (agent.contains ( "Chrome" )) {
 12              // Google 
13              System.out.println ( "Google ...." );
 14          } the else  IF (agent.contains ( " firefox " )) {
 15              System.out.println (" Firefox ... " );
 16          }
 . 17  
18 is  
. 19      }
 20 }

 

@WebServlet("/RequestDemo4")
public class RequestDemo4 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //演示获取请求头数据：referer
        String referer = request.getHeader("referer");
        System.out.println(referer);

        //防盗链
        if(referer != null){
            IF (referer.contains ( "/ Request" )) {
                 // normal access
                // System.out.println ( "normal access");
                 // show Chinese 
                response.setContentType ( "text / html; charset = utf-8" ); 
                . response.getWriter () Write ( "normal access" ); 
            } the else {
                 // Daolian
                 // System.out.println ( "Daolian"); 
                the response.setContentType ( "text / HTML; charset = UTF- 8 " ); 
                . response.getWriter () the Write ( " there is hotlinking is not allowed to access " );
            }
        }
    }
}