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Spring ModelAndView tutorial

Spring ModelAndView tutorial shows how to use ModelAndView in a controller in a Spring web application.

Spring is a popular Java application framework for creating enterprise applications.

ModelAndView

ModelAndView is a holder for both Model and View in the web MVC framework. These two classes are distinct; ModelAndView merely holds both to make it possible for a controller to return both model and view in a single return value.

The view is resolved by a ViewResolver object; the model is data stored in a Map.

Spring ModelAndView example

The following application uses ModelAndView to return a model and a view in one step in a Spring controller. We use Freemarker for view resolving.

pom.xml
src
├───main
│   ├───java
│   │   └───com
│   │       └───zetcode
│   │           ├───config
│   │           │       MyWebInitializer.java
│   │           │       WebConfig.java
│   │           └───controller
│   │                   MyController.java
│   └───resources
│       │   logback.xml
│       └───templates
│               index.ftl
│               show.ftl
└───test
    └───java

This is the project structure.

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.zetcode</groupId>
    <artifactId>springmodelandview</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>war</packaging>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>11</maven.compiler.source>
        <maven.compiler.target>11</maven.compiler.target>
        <spring-version>5.1.3.RELEASE</spring-version>
    </properties>

    <dependencies>

        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-classic</artifactId>
            <version>1.2.3</version>
        </dependency>

        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>4.0.1</version>
            <scope>provided</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context-support</artifactId>
            <version>5.1.3.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.1.3.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.freemarker</groupId>
            <artifactId>freemarker</artifactId>
            <version>2.3.28</version>
        </dependency>

    </dependencies>

    <build>
        <plugins>

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-war-plugin</artifactId>
                <version>3.2.2</version>
            </plugin>

            <plugin>
                <groupId>org.eclipse.jetty</groupId>
                <artifactId>jetty-maven-plugin</artifactId>
                <version>9.4.14.v20181114</version>
            </plugin>

        </plugins>
    </build>
</project>

In the pom.xml we have the necessary dependencies.

resources/logback.xml
<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <logger name="org.springframework" level="ERROR"/>
    <logger name="com.zetcode" level="INFO"/>

    <appender name="consoleAppender" class="ch.qos.logback.core.ConsoleAppender">
        <encoder>
            <Pattern>%d{HH:mm:ss.SSS} %blue(%-5level) %magenta(%logger{36}) - %msg %n
            </Pattern>
        </encoder>
    </appender>

    <root>
        <level value="INFO" />
        <appender-ref ref="consoleAppender" />
    </root>
</configuration>

The logback.xml is a configuration file for the Logback logging library.

com/zetcode/config/MyWebInitializer.java
package com.zetcode.config;

import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;

@Configuration
public class MyWebInitializer extends
        AbstractAnnotationConfigDispatcherServletInitializer {

    @Override
    protected Class<?>[] getRootConfigClasses() {
        return null;
    }

    @Override
    protected Class<?>[] getServletConfigClasses() {
        
        return new Class[]{WebConfig.class};
    }

    @Override
    protected String[] getServletMappings() {
        
        return new String[]{"/"};
    }
}

MyWebInitializer registers the Spring DispatcherServlet, which is a front controller for a Spring web application.

@Override
protected Class<?>[] getServletConfigClasses() {
    
    return new Class[]{WebConfig.class};
}

The getServletConfigClasses() returns a web configuration class.

com/zetcode/config/WebConfig.java
package com.zetcode.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import org.springframework.web.servlet.view.freemarker.FreeMarkerConfigurer;
import org.springframework.web.servlet.view.freemarker.FreeMarkerViewResolver;

@Configuration
@EnableWebMvc
@ComponentScan(basePackages = {"com.zetcode"})
public class WebConfig implements WebMvcConfigurer {

    @Bean
    public FreeMarkerViewResolver freemarkerViewResolver() {

        var resolver = new FreeMarkerViewResolver();
        resolver.setCache(true);
        resolver.setSuffix(".ftl");
        return resolver;
    }

    @Bean
    public FreeMarkerConfigurer freemarkerConfig() {

        var freeMarkerConfigurer = new FreeMarkerConfigurer();
        freeMarkerConfigurer.setTemplateLoaderPath("classpath:/templates/");
        return freeMarkerConfigurer;
    }
}

WebConfig configures FreeMarker template engine. We set the template files location to templates directory on the classpath. (The resources is on the classpath.)

com/zetcode/controller/MyController.java
package com.zetcode.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.servlet.ModelAndView;

import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;

@Controller
public class MyController {

    @GetMapping(value = "/")
    public String home() {

        return "index";
    }

    @GetMapping(value = "/show")
    public ModelAndView show() {

        var mav = new ModelAndView();

        var now = LocalDateTime.now();
        var formatter = DateTimeFormatter.ISO_DATE_TIME;
        var dateTimeFormatted = formatter.format(now);

        mav.addObject("now", dateTimeFormatted);
        mav.setViewName("show");

        return mav;
    }
}

MyController provides two GET mappings.

@GetMapping(value = "/show")
public ModelAndView show() {

The show() method returns a ModelAndView.

var mav = new ModelAndView();

var now = LocalDateTime.now();
var formatter = DateTimeFormatter.ISO_DATE_TIME;
var dateTimeFormatted = formatter.format(now);

mav.addObject("now", dateTimeFormatted);
mav.setViewName("show");

return mav;

A ModelAndView is created and filled with data. The data is a formatted datetime object. The view name is set with setViewName(). Spring resolves the view name to show.ftl.

resources/templates/index.ftl
<!DOCTYPE html>
<html>
    <head>
        <title>Home</title>
        <meta charset="UTF-8">
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
    </head>
    <body>

        <p>
            <a href="show">Show today's datetime</a>
        </p>

    </body>
</html>

The home page contains a link to show today's datetime.

resources/templates/show.ftl
<!DOCTYPE html>
<html>
    <head>
        <title>Today's date</title>
        <meta charset="UTF-8">
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
    </head>
    <body>

        <p>
            Today is: ${now}
        </p>

    </body>
</html>

In the show.ftl view we show the current datetime with ${} syntax.

$ mvn jetty:run

We run the server and locate to localhost:8080 to get the home page, which has the link.

In this tutorial, we have organized model and view with ModelAndView.

You might also be interested in these related tutorials: Spring @Configuration tutorial, Spring @GetMapping tutorial, Java tutorial, or list all Spring tutorials.