Spring MVC

Read Data from Database with Spring Data JPA in Spring MVC


Create Spring MVC Project

On the Eclipse, create a Spring MVC project in Spring Boot

Enter Project Information:

  • Name: LearnSpringMVCWithRealApps
  • Group: com.demo
  • Artifact: LearnSpringMVCWithRealApps
  • Description: Learn Spring MVC with Real Apps
  • Package: com.demo

Select the technologies and libraries to be used:

  • Web
  • JPA
  • MySQL

Click Next button to show Site Information for project

Click Finish button to finish create Spring MVC project




Configure pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0
						http://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>

	<groupId>com.demo</groupId>
	<artifactId>LearnSpringMVCWithRealApps</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<name>LearnSpringMVCWithRealApps</name>
	<description>Learn Spring MVC with Real Apps</description>

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>1.5.2.RELEASE</version>
		<relativePath /> <!-- lookup parent from repository -->
	</parent>

	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
		<java.version>1.8</java.version>
	</properties>

	<dependencies>

		<!-- Spring MVC -->
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>

		<!-- JSTL tag lib -->
		<dependency>
			<groupId>javax.servlet.jsp.jstl</groupId>
			<artifactId>javax.servlet.jsp.jstl-api</artifactId>
			<version>1.2.1</version>
		</dependency>

		<dependency>
			<groupId>taglibs</groupId>
			<artifactId>standard</artifactId>
			<version>1.1.2</version>
		</dependency>

		<!-- Tomcat for JSP rendering -->
		<dependency>
			<groupId>org.apache.tomcat.embed</groupId>
			<artifactId>tomcat-embed-jasper</artifactId>
			<scope>provided</scope>
		</dependency>

		<!-- Spring Data JPA -->
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-data-jpa</artifactId>
		</dependency>

		<!-- MySQL JDBC -->
		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
			<scope>runtime</scope>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>

	</dependencies>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>

</project>

Create Database

Create a database with the name is learn_spring_mvc_with_real_apps. This database have 1 table: Product table

--
-- Table structure for table `product`
--

CREATE TABLE `product` (
  `id` int(11) NOT NULL,
  `name` varchar(250) NOT NULL,
  `price` decimal(10,1) NOT NULL,
  `quantity` int(11) NOT NULL,
  `description` text NOT NULL,
  `status` tinyint(1) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;

--
-- Dumping data for table `product`
--

INSERT INTO `product` (`name`, `price`, `quantity`, `description`, `status`) VALUES('Mobile 2', '1.0', 5, 'description 2', 1);
INSERT INTO `product` (`name`, `price`, `quantity`, `description`, `status`) VALUES('Mobile 1', '2.0', 2, 'description 1', 1);
INSERT INTO `product` (`name`, `price`, `quantity`, `description`, `status`) VALUES('Mobile 3', '3.0', 9, 'description 3', 1);
INSERT INTO `product` (`name`, `price`, `quantity`, `description`, `status`) VALUES('Computer 1', '5.0', 12, 'description 4', 0);
INSERT INTO `product` (`name`, `price`, `quantity`, `description`, `status`) VALUES('Computer 2', '7.0', 5, 'description 5', 1);
INSERT INTO `product` (`name`, `price`, `quantity`, `description`, `status`) VALUES('Computer 3', '12.0', 2, 'description 6', 1);
INSERT INTO `product` (`name`, `price`, `quantity`, `description`, `status`) VALUES('Laptop 1', '3.0', 8, 'description 7', 0);
INSERT INTO `product` (`name`, `price`, `quantity`, `description`, `status`) VALUES('Laptop 2', '4.0', 11, 'description 8', 0);
INSERT INTO `product` (`name`, `price`, `quantity`, `description`, `status`) VALUES('Laptop 3', '2.0', 15, 'description 9', 1);

Structure of Product Table

Data of Product Table




Configure application.properties

spring.mvc.view.prefix = /WEB-INF/views/
spring.mvc.view.suffix = .jsp
spring.mvc.static-path-pattern=/resources/**

spring.datasource.url= jdbc:mysql://localhost:3306/learn_spring_mvc_with_real_apps
spring.datasource.username=root
spring.datasource.password=123456

server.port=9596

Entities Class

Create new package, named com.demo.entities. In this package, create entities class as below:

Product Entity

Create new java class, named Product.java

package com.demo.entities;

import java.math.BigDecimal;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name = "product")
public class Product {

	@Id
	@GeneratedValue(strategy = GenerationType.IDENTITY)
	private int id;

	@Column
	private String name;

	@Column
	private BigDecimal price;

	@Column
	private int quantity;

	@Column
	private String description;

	@Column
	private boolean status;

	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 BigDecimal getPrice() {
		return price;
	}

	public void setPrice(BigDecimal price) {
		this.price = price;
	}

	public int getQuantity() {
		return quantity;
	}

	public void setQuantity(int quantity) {
		this.quantity = quantity;
	}

	public String getDescription() {
		return description;
	}

	public void setDescription(String description) {
		this.description = description;
	}

	public boolean isStatus() {
		return status;
	}

	public void setStatus(boolean status) {
		this.status = status;
	}

}

Create ProductRepository Interface

Create new package named com.demo.repositories. In this package create the ProductRepository interface implements from CrudRepository interface of Spring Data JPA that provides CRUD Operations for an entity.

package com.demo.repositories;

import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Repository;
import com.demo.entities.Product;

@Repository("productRepository")
public interface ProductRepository extends CrudRepository<Product, Integer> {
}




Create ProductService Interface

Create new package named com.demo.services. In this package create the ProductService interface as below:

package com.demo.services;

import demo.entities.Product;

public interface ProductService {

	public Iterable<Product> findAll();

}

Create ProductServiceImpl class

In com.demo.services package, create ProductServiceImpl class implements method from ProductService interfaces

package com.demo.repositories;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import com.demo.entities.Product;
import com.demo.services.ProductService;

@Transactional
@Service("productService")
public class ProductServiceImpl implements ProductService {

	@Autowired
	private ProductRepository productRepository;

	@Override
	public Iterable<Product> findAll() {
		return productRepository.findAll();
	}

}

Create Controllers

Create new package named com.demo.controllers. In this package, create controller as below:

ProductController

Create new java class, named ProductController.java

package com.demo.controllers;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import com.demo.services.ProductService;

@Controller
@RequestMapping("product")
public class ProductController {

	@Autowired
	private ProductService productService;

	@RequestMapping(method = RequestMethod.GET)
	public String index(ModelMap modelMap) {
		modelMap.put("products", productService.findAll());
		return "product/index";
	}

}

Create Views

Create new folders with path webapp\WEB-INF\views in src\main. In views folder, create JSP Pages as below:

Index View

Create new folder named product. Create new JSP file named index.jsp

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Products List</title>
</head>
<body>

	<h3>Products List</h3>
	<table border="1" cellpadding="2" cellspacing="2">
		<tr>
			<th>Id</th>
			<th>Name</th>
			<th>Description</th>
			<th>Status</th>
			<th>Price</th>
			<th>Quantity</th>
		</tr>
		<c:forEach var="product" items="${products }">
			<tr>
				<td>${product.id }</td>
				<td>${product.name }</td>
				<td>${product.description }</td>
				<td>${product.status }</td>
				<td>${product.price }</td>
				<td>${product.quantity }</td>
			</tr>
		</c:forEach>
	</table>

</body>
</html>

Structure of Spring MVC Project




Run Application

Select LearnSpringMVCWithRealAppsApplication.java file in com.demo package, right click and select Run As/Spring Boot App menu

Access index method in product controller with following url: http://localhost:9596/product

Output

References

I recommend you refer to the books below to learn more about the knowledge in this article:


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