Invoke JavaScript function from servlet
In this section, you will learn how to call JavaScript function from the servlet.
In this section, you will learn how to call JavaScript function from the servlet.
Invoke JavaScript function from servlet
You have learnt several servlet related examples. Here we are going to create
an example that will call JavaScript function from the servlet. Embedding
JavaScript in Servlets can be useful when migrating Web applications that rely
on JavaScript to server-side Java without rewriting the business logic.
Description Of Code:
You can see in the given code, we have retrieved database table data into the
html tables. We have also embedded delete button in every row of html table to
allow the user to select the particular record to delete. This delete button
calls the javascript function for the particular record. Before deleting, it
will ask the user whether he/she really want to delete the record. If ok, then
it will take the id of the specific record and navigate to delteuser.jsp that
will delete the record.
Here is the code of Servlet.java:
|
import java.io.*;
import java.sql.*;
import
java.util.*;
import
javax.servlet.*;
import
javax.servlet.http.*;
public
class
Servlet extends
HttpServlet {
public void
doGet(HttpServletRequest request, HttpServletResponse response)
throws
IOException, ServletException {
PrintWriter out = response.getWriter();
out.println("<html><head><script>function
deleteRecord(id){var r=confirm('Are you confirm')");
out.println("if (r==true){var
reason=prompt('Reason for deleting:')");
out.println("if(reason!=null){");
out.println("window.open('http://localhost:8080/examples/modified/deleteuser.jsp?id='+id+'&&reas='+reason,'mywindow','width=500,
height=350,toolbar=no,resizable=yes,menubar=yes')");
out.println("}else{}}}</script></head>");
out.println("<form
name='form'>");
out.println("<table
border='1'>");
out.println("<tr><th>FirstName</th><th>LastName</th><th>Address</th><th>Email</th></tr>");
Connection con = null;
String url = "jdbc:mysql://localhost:3306/";
String db = "test";
String driver = "com.mysql.jdbc.Driver";
String userName = "root";
String password = "root";
int
sumcount = 0;
Statement st;
try {
Class.forName(driver).newInstance();
con = DriverManager.getConnection(url + db, userName, password);
String query = "select * from
employee";
st = con.createStatement();
ResultSet rs = st.executeQuery(query);
while (rs.next())
{
out.println("<tr><td>"
+ rs.getString(2) + "</td><td>"+
rs.getString(3) + "</td><td>"
+ rs.getString(4)+ "</td><td>"
+ rs.getString(5) + "</td>");
out.println("<td><input
type='button' name='edit' value='Delete' style='background-color:red;font-weight:bold;color:#ffffff;'
onclick=\"deleteRecord('"+ rs.getString(1)
+ "');\"></td></tr>");
}
} catch
(Exception e) {
e.printStackTrace();}
out.println("</table>");
out.println("<form>");
out.println("</html>");
}
} |
Here is the code of deleteuser.jsp:
|
<%@page language="java"%>
<%@page import="java.sql.*"%>
<%
String id=request.getParameter("id");
int no=Integer.parseInt(id);
int sumcount=0;
try {
Class.forName("com.mysql.jdbc.Driver").newInstance();
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/test",
"root", "root");
String query = "select * from register where
id='"+no+"'";
Statement st = conn.createStatement();
st.executeUpdate("DELETE FROM register WHERE id =
'"+no+"'");
out.println("Record is deleted successfully");
}
catch(Exception e){}
%> |
