Search from Database In Servlet
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In this section, we have developed an Employee Search application. We created
three file search.jsp, viewSearch.jsp and Search.java.
Brief description of the flow of the
application:
- User opens search.jsp in the browser and
enter the search text and click on the "Search" button.
- Search.java retrieves data from the
database according to the Search text.
- viewSearch.jsp display the search data from
database on the browser.
Step 1: Create a web page ("search.jsp") to Search the user.
<html>
<head>
</head>
<body>
<br><br><br><br><br><br>
<form method="post" name="frm" action="search">
<table border="0" width="300" align="center" bgcolor="#CDFFFF">
<tr><td colspan=2 style="font-size:12pt;color:#00000;" align="center">
<h3>Search Employee</h3></td></tr>
<tr><td ><b>Employee Name</b></td>
<td>: <input type="text" name="emp_name" id="emp_name">
</td></tr>
<tr><td ><b>Department</b></td>
<td>: <input type="text" name="emp_dept" id="emp_dept">
</td></tr>
<tr><td ><b>Email</b></td>
<td>: <input type="text" name="email" id="email">
</td></tr>
<tr><td colspan=2 align="center">
<input type="submit" name="submit" value="Search"></td></tr>
</table>
</form>
</body>
</html> |
Step:2Create a
Servlet ("Search.java") to retrieve the data.
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.sql.*;
import java.sql.*;
import java.util.*;
public class Search extends HttpServlet{
public void doPost(HttpServletRequest request,
HttpServletResponse response)
throws ServletException,IOException{
response.setContentType("text/html");
PrintWriter out = response.getWriter();
System.out.println("MySQL Connect Example.");
Connection conn = null;
String url = "jdbc:mysql://localhost:3306/";
String dbName = "userdetails";
String driver = "com.mysql.jdbc.Driver";
String userName = "root";
String password = "root";
Statement st;
try {
Class.forName(driver).newInstance();
conn = DriverManager.getConnection(url+dbName,userName,password);
System.out.println("Connected to the database");
String emp_name = request.getParameter("emp_name");
String emp_dept = request.getParameter("emp_dept");
String email = request.getParameter("email");
ArrayList al=null;
ArrayList emp_list =new ArrayList();
String query =
"select * from employee where employee_name='"+emp_name+"' or
department='"+emp_dept+"' or email='"+email+"'
order by employee_name";
System.out.println("query " + query);
st = conn.createStatement();
ResultSet rs = st.executeQuery(query);
while(rs.next()){
al = new ArrayList();
al.add(rs.getString(1));
al.add(rs.getString(2));
al.add(rs.getString(3));
al.add(rs.getString(4));
al.add(rs.getString(5));
al.add(rs.getString(6));
al.add(rs.getString(7));
al.add(rs.getString(8));
al.add(rs.getString(10));
System.out.println("al :: "+al);
emp_list.add(al);
}
request.setAttribute("empList",emp_list);
System.out.println("empList " + emp_list);
// out.println("emp_list " + emp_list);
String nextJSP = "/viewSearch.jsp";
RequestDispatcher dispatcher =
getServletContext().getRequestDispatcher(nextJSP);
dispatcher.forward(request,response);
conn.close();
System.out.println("Disconnected from database");
} catch (Exception e) {
e.printStackTrace();
}
}
}
|
RequestDispatcher dispatcher = getServletContext().getRequestDispatcher(nextJSP);
dispatcher.forward(request,response);
The ServletContext.getRequestDispatcher()
method takes a String argument describing a path
within the scope of the ServletContext. This
path must be relative to the root of the ServletContext
and begin with a '/'. The method uses the path to look up
a Servlet, using the Servlet path matching rules, wraps it with a RequestDispatcher object, and returns
the resulting object. If no Servlet can be resolved based on the given path, a RequestDispatcher is
provided that returns the content for that path.
Step 4:
"web.xml" to mapping the Servlet ("Search.java")
<?xml version="1.0" encoding="ISO-8859-1"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
version="2.5">
<display-name>Welcome to Tomcat</display-name>
<description>
Welcome to Tomcat
</description>
<servlet>
<servlet-name>searchServlet</servlet-name>
<servlet-class>Search</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>searchServlet</servlet-name>
<url-pattern>/search</url-pattern>
</servlet-mapping>
</web-app>
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Step 4:
"viewSearch.jsp" to display the data.
<%@ page import="java.util.*" %>
<html>
<head>
</head>
<body>
<br><br><br><br><br><br>
<table width="700px" align="center"
style="border:1px solid #000000;">
<tr>
<td colspan=8 align="center"
style="background-color:ffeeff">
<b>Employee Record</b></td>
</tr>
<tr style="background-color:efefef;">
<td><b>Employee Name</b></td>
<td><b>Username</b></td>
<td><b>Email</b></td>
<td><b>Contact No</b></td>
<td><b>Address</b></td>
<td><b>Country</b></td>
<td><b>State</b></td>
<td><b>Department</b></td>
</tr>
<%
int count=0;
String color = "#F9EBB3";
if(request.getAttribute("empList")!=null)
{
ArrayList al = (ArrayList)request.getAttribute("empList");
Iterator itr = al.iterator();
while(itr.hasNext()){
if((count%2)==0){
color = "#eeffee";
}
else{
color = "#F9EBB3";
}
count++;
ArrayList empList = (ArrayList)itr.next();
%>
<tr style="background-color:<%=color%>;">
<td><%=empList.get(0)%></td>
<td><%=empList.get(1)%></td>
<td><%=empList.get(3)%></td>
<td><%=empList.get(4)%></td>
<td><%=empList.get(5)%></td>
<td><%=empList.get(6)%></td>
<td><%=empList.get(7)%></td>
<td><%=empList.get(8)%></td>
</tr>
<%
}
}
%>
<%
if(count==0){
%>
<tr>
<td colspan=8 align="center"
style="background-color:eeffee"><b>No Record</b></td>
</tr>
<%
}
%>
</table>
</body>
</html>
|
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Output of this Program:
search.jsp to search the Employee
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After search the result.
If no record in the database then display No Record.
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Download the application