Java Servlet and JDBC Example | Insert data in MySQL
Prerequisites: Servlet, JDBC Connectivity
To start with interfacing Java Servlet Program with JDBC Connection:
- Proper JDBC Environment should set-up along with database creation.
- To do so, download the mysql-connector.jar file from the internet,
- As it is downloaded, move the jar file to the apache-tomcat server folder,
- Place the file in lib folder present in the apache-tomcat directory.
- To start with the basic concept of interfacing:
- Step 1: Creation of Database and Table in MySQL
As soon as jar file is placed in the folder, create a database and table in MySQL,
mysql> create database demoprj; Query OK, 1 row affected (4.10 sec) mysql> use demoprj Database changed mysql> create table demo(id int(10), string varchar(20)); Query OK, 0 rows affected (1.93 sec) mysql> desc demo; +--------+-------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +--------+-------------+------+-----+---------+-------+ | id | int(10) | YES | | NULL | | | string | varchar(20) | YES | | NULL | | +--------+-------------+------+-----+---------+-------+ 2 rows in set (0.40 sec)
- Step 2: Implementation of required Web-pages
Create a form in HTML file, where take all the inputs required to insert data into the database. Specify the servlet name in it, with the POST method as security is important aspects in database connectivity.<!DOCTYPE html>
<
html
>
<
head
>
<
title
>Insert Data</
title
>
</
head
>
<
body
>
<!-- Give Servlet reference to the form as an instances
GET and POST services can be according to the problem statement-->
<
form
action
=
"./InsertData"
method
=
"post"
>
<
p
>ID:</
p
>
<!-- Create an element with mandatory name attribute,
so that data can be transfer to the servlet using getParameter() -->
<
input
type
=
"text"
name
=
"id"
/>
<
br
/>
<
p
>String:</
p
>
<
input
type
=
"text"
name
=
"string"
/>
<
br
/><
br
/><
br
/>
<
input
type
=
"submit"
/>
</
form
>
</
body
>
</
html
>
Output:
Submit the data (with validation) as all the required data are inserted.
- Step 3: Creation of Java Servlet program with JDBC Connection
To create a JDBC Connection steps are
- Import all the packages
- Register the JDBC Driver
- Open a connection
- Execute the query, and retrieve the result
- Clean up the JDBC Environment
Create a separate class to create a connection of database, as it is a lame process to writing the same code snippet in all the program. Create a .java file which returns a Connection object.
import
java.sql.Connection;
import
java.sql.DriverManager;
import
java.sql.SQLException;
// This class can be used to initialize the database connection
public
class
DatabaseConnection {
protected
static
Connection initializeDatabase()
throws
SQLException, ClassNotFoundException
{
// Initialize all the information regarding
// Database Connection
String dbDriver =
"com.mysql.jdbc.Driver"
;
String dbURL =
"jdbc:mysql:// localhost:3306/"
;
// Database name to access
String dbName =
"demoprj"
;
String dbUsername =
"root"
;
String dbPassword =
"root"
;
Class.forName(dbDriver);
Connection con = DriverManager.getConnection(dbURL + dbName,
dbUsername,
dbPassword);
return
con;
}
}
- Step 4: To use this class method, create an object in Java Servlet program
Below program shows Servlet Class which create a connection and insert the data in the
demo
table,import
java.io.IOException;
import
java.io.PrintWriter;
import
java.sql.Connection;
import
java.sql.PreparedStatement;
import
javax.servlet.ServletException;
import
javax.servlet.annotation.WebServlet;
import
javax.servlet.http.HttpServlet;
import
javax.servlet.http.HttpServletRequest;
import
javax.servlet.http.HttpServletResponse;
// Import Database Connection Class file
import
code.DatabaseConnection;
// Servlet Name
@WebServlet
(
"/InsertData"
)
public
class
InsertData
extends
HttpServlet {
private
static
final
long
serialVersionUID = 1L;
protected
void
doPost(HttpServletRequest request,
HttpServletResponse response)
throws
ServletException, IOException
{
try
{
// Initialize the database
Connection con = DatabaseConnection.initializeDatabase();
// Create a SQL query to insert data into demo table
// demo table consists of two columns, so two '?' is used
PreparedStatement st = con
.prepareStatement(
"insert into demo values(?, ?)"
);
// For the first parameter,
// get the data using request object
// sets the data to st pointer
st.setInt(
1
, Integer.valueOf(request.getParameter(
"id"
)));
// Same for second parameter
st.setString(
2
, request.getParameter(
"string"
));
// Execute the insert command using executeUpdate()
// to make changes in database
st.executeUpdate();
// Close all the connections
st.close();
con.close();
// Get a writer pointer
// to display the successful result
PrintWriter out = response.getWriter();
out.println(
"<html><body><b>Successfully Inserted"
+
"</b></body></html>"
);
}
catch
(Exception e) {
e.printStackTrace();
}
}
}
- Step 5: Get the data from the HTML file
To get the data from the HTML file, the request object is used which calls getParameter() Method to fetch the data from the channel. After successful insertion, the writer object is created to display a success message.
After insertion operation from Servlet, data will be reflected in MySQL Database
Output:
Result in MySQL Interface
mysql> select * from demo; +------+---------------+ | id | string | +------+---------------+ | 1 | w3wiki | +------+---------------+ 1 row in set (0.06 sec)
- Step 1: Creation of Database and Table in MySQL
This article shows the basic connection of JDBC with Java Servlet Program, to insert data in large volume then proper validation should be done as if any data which is not in proper format will encounter an error. All the data inserting in Database should be encrypted.