Java Code Guru Ji (8920128728): Spring MVC CRUD Example

CRUD (Create, Read, Update and Delete) application is the most important application for creating any project. It provides an idea to develop a large project. In spring MVC, we can develop a simple CRUD application.

Here, we are using JdbcTemplate for database interaction.

Create a table

Here, we are using emp99 table present in the MySQL database. It has 4 fields: id, name, salary, and designation. Here, id is auto incremented which is generated by the sequence.

Spring MVC CRUD Example

1. Add dependencies to pom.xml file.

pom.xml

 <!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc -->  
<dependency>  
    <groupId>org.springframework</groupId>  
    <artifactId>spring-webmvc</artifactId>  
    <version>5.1.1.RELEASE</version>  
</dependency>  
  
<!-- https://mvnrepository.com/artifact/org.apache.tomcat/tomcat-jasper -->  
<dependency>  
    <groupId>org.apache.tomcat</groupId>  
    <artifactId>tomcat-jasper</artifactId>  
    <version>9.0.12</version>  
</dependency>  
    <!-- https://mvnrepository.com/artifact/javax.servlet/javax.servlet-api -->  
<dependency>    
    <groupId>javax.servlet</groupId>    
    <artifactId>servlet-api</artifactId>    
    <version>3.0-alpha-1</version>    
</dependency>  
<!-- https://mvnrepository.com/artifact/javax.servlet/jstl -->  
<dependency>  
    <groupId>javax.servlet</groupId>  
    <artifactId>jstl</artifactId>  
    <version>1.2</version>  
</dependency>  
    <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->  
<dependency>  
    <groupId>mysql</groupId>  
    <artifactId>mysql-connector-java</artifactId>  
    <version>8.0.11</version>  
</dependency>  
    <!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc -->  
<dependency>  
    <groupId>org.springframework</groupId>  
    <artifactId>spring-jdbc</artifactId>  
    <version>5.1.1.RELEASE</version>  
</dependency>  

2. Create the bean class

Here, the bean class contains the variables (along setter and getter methods) corresponding to the fields exist in the database.

Emp.java

package com.javatpoint.beans;
public class Emp {
private int id;
private String name;
private float salary;
private String designation;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public float getSalary() {
return salary;
}
public void setSalary(float salary) {
this.salary = salary;
}
public String getDesignation() {
return designation;
}
public void setDesignation(String designation) {
this.designation = designation;
}
}

3. Create the controller class

EmpController.java

package com.javatpoint.controllers;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import com.javatpoint.beans.Emp;
import com.javatpoint.dao.EmpDao;
@Controller
public class EmpController {
@Autowired
EmpDao dao;//will inject dao from XML file
/*It displays a form to input data, here "command" is a reserved request attribute
*which is used to display object data into form
*/
@RequestMapping("/empform")
public String showform(Model m){
m.addAttribute("command", new Emp());
return "empform";
}
/*It saves object into database. The @ModelAttribute puts request data
* into model object. You need to mention RequestMethod.POST method
* because default request is GET*/
@RequestMapping(value="/save",method = RequestMethod.POST)
public String save(@ModelAttribute("emp") Emp emp){
dao.save(emp);
return "redirect:/viewemp";//will redirect to viewemp request mapping
}
/* It provides list of employees in model object */
@RequestMapping("/viewemp")
public String viewemp(Model m){
List<Emp> list=dao.getEmployees();
m.addAttribute("list",list);
return "viewemp";
}
/* It displays object data into form for the given id.
* The @PathVariable puts URL data into variable.*/
@RequestMapping(value="/editemp/{id}")
public String edit(@PathVariable int id, Model m){
Emp emp=dao.getEmpById(id);
m.addAttribute("command",emp);
return "empeditform";
}
/* It updates model object. */
@RequestMapping(value="/editsave",method = RequestMethod.POST)
public String editsave(@ModelAttribute("emp") Emp emp){
dao.update(emp);
return "redirect:/viewemp";
}
/* It deletes record for the given id in URL and redirects to /viewemp */
@RequestMapping(value="/deleteemp/{id}",method = RequestMethod.GET)
public String delete(@PathVariable int id){
dao.delete(id);
return "redirect:/viewemp";
}
}

4. Create the DAO class

Let's create a DAO class to access the required data from the database.

EmpDao.java

package com.javatpoint.dao;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;
import com.javatpoint.beans.Emp;
public class EmpDao {
JdbcTemplate template;
public void setTemplate(JdbcTemplate template) {
this.template = template;
}
public int save(Emp p){
String sql="insert into Emp99(name,salary,designation) values('"+p.getName()+"',"+p.getSalary()+",'"+p.getDesignation()+"')";
return template.update(sql);
}
public int update(Emp p){
String sql="update Emp99 set name='"+p.getName()+"', salary="+p.getSalary()+",designation='"+p.getDesignation()+"' where id="+p.getId()+"";
return template.update(sql);
}
public int delete(int id){
String sql="delete from Emp99 where id="+id+"";
return template.update(sql);
}
public Emp getEmpById(int id){
String sql="select * from Emp99 where id=?";
return template.queryForObject(sql, new Object[]{id},new BeanPropertyRowMapper<Emp>(Emp.class));
}
public List<Emp> getEmployees(){
return template.query("select * from Emp99",new RowMapper<Emp>(){
public Emp mapRow(ResultSet rs, int row) throws SQLException {
Emp e=new Emp();
e.setId(rs.getInt(1));
e.setName(rs.getString(2));
e.setSalary(rs.getFloat(3));
e.setDesignation(rs.getString(4));
return e;
}
});
}
}

5. Provide the entry of controller in the web.xml file

web.xml

<?xml version="1.0" encoding="UTF-8"?>  
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">  
  <display-name>SpringMVC</display-name>  
   <servlet>    
    <servlet-name>spring</servlet-name>    
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>    
    <load-on-startup>1</load-on-startup>      
</servlet>    
<servlet-mapping>    
    <servlet-name>spring</servlet-name>    
    <url-pattern>/</url-pattern>    
</servlet-mapping>    
</web-app>  

6. Define the bean in the xml file

spring-servlet.xml

<?xml version="1.0" encoding="UTF-8"?>  
<beans xmlns="http://www.springframework.org/schema/beans"  
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"   
    xmlns:context="http://www.springframework.org/schema/context"  
    xmlns:mvc="http://www.springframework.org/schema/mvc"  
    xsi:schemaLocation="  
        http://www.springframework.org/schema/beans  
        http://www.springframework.org/schema/beans/spring-beans.xsd  
        http://www.springframework.org/schema/context  
        http://www.springframework.org/schema/context/spring-context.xsd  
        http://www.springframework.org/schema/mvc  
        http://www.springframework.org/schema/mvc/spring-mvc.xsd">  
<context:component-scan base-package="com.javatpoint.controllers"></context:component-scan>    
    
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">    
<property name="prefix" value="/WEB-INF/jsp/"></property>    
<property name="suffix" value=".jsp"></property>    
</bean>    
    
<bean id="ds" class="org.springframework.jdbc.datasource.DriverManagerDataSource">    
<property name="driverClassName" value="com.mysql.jdbc.Driver"></property>    
<property name="url" value="jdbc:mysql://localhost:3306/test"></property>    
<property name="username" value=""></property>    
<property name="password" value=""></property>    
</bean>    
    
<bean id="jt" class="org.springframework.jdbc.core.JdbcTemplate">    
<property name="dataSource" ref="ds"></property>    
</bean>    
    
<bean id="dao" class="com.javatpoint.dao.EmpDao">    
<property name="template" ref="jt"></property>    
</bean>       
</beans>  

7. Create the requested page

index.jsp

<a href="empform">Add Employee</a>  
<a href="viewemp">View Employees</a>  

8. Create the other view components

empform.jsp

<%@ taglib uri="http://www.springframework.org/tags/form" prefix="form"%>    
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>    
  
        <h1>Add New Employee</h1>  
       <form:form method="post" action="save">    
        <table >    
         <tr>    
          <td>Name : </td>   
          <td><form:input path="name"  /></td>  
         </tr>    
         <tr>    
          <td>Salary :</td>    
          <td><form:input path="salary" /></td>  
         </tr>   
         <tr>    
          <td>Designation :</td>    
          <td><form:input path="designation" /></td>  
         </tr>   
         <tr>    
          <td> </td>    
          <td><input type="submit" value="Save" /></td>    
         </tr>    
        </table>    
       </form:form>    

empeditform.jsp

Here "/SpringMVCCRUDSimple" is the project name, change this if you have different project name. For live application, you can provide full URL.

<%@ taglib uri="http://www.springframework.org/tags/form" prefix="form"%>    
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>    
  
        <h1>Edit Employee</h1>  
       <form:form method="POST" action="/SpringMVCCRUDSimple/editsave">    
        <table >    
        <tr>  
        <td></td>    
         <td><form:hidden  path="id" /></td>  
         </tr>   
         <tr>    
          <td>Name : </td>   
          <td><form:input path="name"  /></td>  
         </tr>    
         <tr>    
          <td>Salary :</td>    
          <td><form:input path="salary" /></td>  
         </tr>   
         <tr>    
          <td>Designation :</td>    
          <td><form:input path="designation" /></td>  
         </tr>   
           
         <tr>    
          <td> </td>    
          <td><input type="submit" value="Edit Save" /></td>    
         </tr>    
        </table>    
       </form:form>    

viewemp.jsp

   <%@ taglib uri="http://www.springframework.org/tags/form" prefix="form"%>    
   <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>    
  
<h1>Employees List</h1>  
<table border="2" width="70%" cellpadding="2">  
<tr><th>Id</th><th>Name</th><th>Salary</th><th>Designation</th><th>Edit</th><th>Delete</th></tr>  
   <c:forEach var="emp" items="${list}">   
   <tr>  
   <td>${emp.id}</td>  
   <td>${emp.name}</td>  
   <td>${emp.salary}</td>  
   <td>${emp.designation}</td>  
   <td><a href="editemp/${emp.id}">Edit</a></td>  
   <td><a href="deleteemp/${emp.id}">Delete</a></td>  
   </tr>  
   </c:forEach>  
   </table>  
   <br/>  
   <a href="empform">Add New Employee</a>  