In com.xdl.servlet package definition RandomServlet class HttpServlet class and generates a random number and sends the client class. Detailed RandomServlet class code as follows:
package com.xdl.servlet;
import java.io.IOException;
import java.io.PrintWriter;
java.util.Random import;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
@WebServlet("/randomValue")
public class RandomValue extends HttpServlet {
protected void service(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
Random random = new Random();
int r = random.nextInt(100);
PrintWriter pw = response.getWriter ();
pw.write("" + r);
pw.close();
}
}
Write client page random.html, define a page button using Ajax sends a request to obtain a random number returned by the server and displayed on the page. Random.html detailed code as follows:
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Title</title>
<script type="text/javascript" src="js/jquery-3.3.1.js"></script>
<script type="text/javascript">
getRandom function () {
$.ajax({
url:'randomValue',
type:'type',
async:true,
data:{},
dataType:'json',
success:function(result){
$('#sp1').html(result);
},
error:function(){
alert ( "wrong");
}
});
}
</script>
</head>
<body>
<Button type = "button" onclick = "getRandom ()"> acquired random number </ button> <br>
<span id="sp1"></span>
</body>
</html>
Now start the Tomcat server, open the browser and type http: // localhost: 8080 / random / random.html. Then click on the page acquired random number button to display the page as shown in FIG. 1, a random number acquired repeatedly clicking a button, the digital conversion page will be repeated.
Figure 1 shows a random number in the page
Reproduced in: https: //my.oschina.net/u/4125915/blog/3059960