Spring MVC

Object Conversion 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

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>

		<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>

Configure application.properties

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

server.port=9596




Entities Class

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

Role Entity

Create new java class, named Role.java

package com.demo.entities;

public class Role {

	private String id;
	private String name;

	public String getId() {
		return id;
	}

	public void setId(String id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public Role() {
	}

	public Role(String id, String name) {
		this.id = id;
		this.name = name;
	}

}

Account Entity

Create new java class, named Account.java

package com.demo.entities;

public class Account {

	private String username;
	private String fullName;
	private Role role;

	public String getUsername() {
		return username;
	}

	public void setUsername(String username) {
		this.username = username;
	}

	public String getFullName() {
		return fullName;
	}

	public void setFullName(String fullName) {
		this.fullName = fullName;
	}

	public Role getRole() {
		return role;
	}

	public void setRole(Role role) {
		this.role = role;
	}

}

Create Conversion

Create new package named com.demo.conversion. In this package, create new conversion named RoleEditor as below:

package com.demo.conversion;

import java.beans.PropertyEditorSupport;
import com.demo.entities.Role;
import com.demo.models.RoleModel;

public class RoleEditor extends PropertyEditorSupport {

	@Override
	public void setAsText(String id) throws IllegalArgumentException {
		try {
			RoleModel roleModel = new RoleModel();
			this.setValue(roleModel.find(id));
		} catch (Exception e) {
			this.setValue(null);
		}
	}

	@Override
	public String getAsText() {
		Role role = (Role) getValue();
		return role.getId();
	}

}




Models Class

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

package com.demo.models;

import java.util.ArrayList;
import java.util.List;
import com.demo.entities.Role;

public class RoleModel {

	private List<Role> roles;

	public RoleModel() {
		this.roles = new ArrayList<Role>();
		this.roles.add(new Role("r1", "Role 1"));
		this.roles.add(new Role("r2", "Role 2"));
		this.roles.add(new Role("r3", "Role 3"));
		this.roles.add(new Role("r4", "Role 4"));
	}

	public List<Role> findAll() {
		return this.roles;
	}

	public Role find(String id) {
		for (Role role : this.roles) {
			if (role.getId().equalsIgnoreCase(id)) {
				return role;
			}
		}
		return null;
	}

}

Create Controller

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

package com.demo.controllers;

import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.WebDataBinder;
import org.springframework.web.bind.annotation.InitBinder;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import com.demo.conversion.RoleEditor;
import com.demo.entities.Account;
import com.demo.entities.Role;
import com.demo.models.RoleModel;

@Controller
@RequestMapping(value = "account")
public class AccountController {

	@InitBinder
	public void initBinder(WebDataBinder webDataBinder) {
		webDataBinder.registerCustomEditor(Role.class, new RoleEditor());
	}

	@RequestMapping(method = RequestMethod.GET)
	public String index(ModelMap modelMap) {
		RoleModel roleModel = new RoleModel();
		Account account = new Account();
		account.setRole(roleModel.find("r3"));
		modelMap.put("account", account);
		modelMap.put("roles", roleModel.findAll());
		return "account/index";
	}

	@RequestMapping(value = "save", method = RequestMethod.POST)
	public String save(@ModelAttribute("account") Account account, ModelMap modelMap) {
		modelMap.put("account", account);
		return "account/success";
	}

}




Create Views

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

Index View

Create new jsp file named index.jsp

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
	pageEncoding="ISO-8859-1"%>
<%@ taglib prefix="s" uri="http://www.springframework.org/tags/form"%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>

	<h3>Account Register</h3>
	<s:form method="post" commandName="account"
		action="${pageContext.request.contextPath }/account/save">
		<table cellpadding="2" cellspacing="2" border="0">
			<tr>
				<td>Username</td>
				<td><s:input path="username" /></td>
			</tr>
			<tr>
				<td>Full Name</td>
				<td><s:input path="fullName" /></td>
			</tr>
			<tr>
				<td>Role</td>
				<td>
					<s:select path="role" items="${roles }"
								itemValue="id" itemLabel="name"></s:select>
				</td>
			</tr>
			<tr>
				<td>&nbsp;</td>
				<td><input type="submit" value="Save" /></td>
			</tr>
		</table>
	</s:form>

</body>
</html>

Success View

Create new jsp file named success.jsp

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
	pageEncoding="ISO-8859-1"%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Account Info</title>
</head>
<body>

	<h3>Account Info</h3>
	<table cellpadding="2" cellspacing="2" border="1">
		<tr>
			<td>Username</td>
			<td>${account.username }</td>
		</tr>
		<tr>
			<td>Full Name</td>
			<td>${account.fullName }</td>
		</tr>
		<tr>
			<td>Role Id</td>
			<td>${account.role.id }</td>
		</tr>
		<tr>
			<td>Role Name</td>
			<td>${account.role.name }</td>
		</tr>
	</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 account controller with following url: http://localhost:9596/account

Output

Click Save button submit form to save method in account controller with following url: http://localhost:9596/account/save

Output

References

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


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