Maven – How to create a multi module project

In this tutorial, we will show you how to use Maven to manage a Multi-module project containing four modules :

  1. Password module – Interface only.
  2. Password md5 module – Password module implementation, MD5 password hashing.
  3. Password sha module – Password module implementation, SHA password hashing.
  4. Web module – A simple MVC web app to hash an input with either MD5 or SHA algorithm.

The module dependency.


$ password 

$ password <-- password-md5

$ password <-- password-sha

$ web <-- (password-md5 | password-sha) <-- password

Some commands to a build a multi-module project, for examples :


$ mvn -pl password compile	# compile password module only	

$ mvn -pl password-sha compile	# compile password-sha module, also dependency - password

$ mvn -pl web compile		# compile web module only	

$ mvn -am -pl web compile	# compile web module, also dependency - password-sha or password-md5, password

$ mvn -pl web jetty:run 	# run web module with Jetty

$ mvn compile 			# compile everything

Technologies used :

  1. Maven 3.5.3
  2. JDK 8
  3. Spring 5.1.0.RELEASE
  4. thymeleaf 3.0.10.RELEASE

1. Directory Structure

In a multi-module project layout, a parent project contains a parent pom.xml and each sub modules (sub projects) also containing own pom.xml

2. Maven POM

Let review the Maven multi-module POM files.

2.1 A Parent POM file, packaging is pom.

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>

	<!-- parent pom -->
    <groupId>com.mkyong.multi</groupId>
    <artifactId>java-multi-modules</artifactId>
    <packaging>pom</packaging>
	<version>1.0</version>

	<!-- sub modules -->
	<modules>
        <module>web</module>
        <module>password</module>
        <module>password-sha</module>
        <module>password-md5</module>
    </modules>
	
</project>

2.2 In password module.

password/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">

	<!-- parent pom -->
    <parent>
        <artifactId>java-multi-modules</artifactId>
        <groupId>com.mkyong.multi</groupId>
        <version>1.0</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

	<!-- password info -->
    <groupId>com.mkyong.password</groupId>
    <artifactId>password</artifactId>
    <version>1.0</version>
    <packaging>jar</packaging>
	
</project>

2.3 In password-md5 module.

password-md5/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">
		 
    <parent>
        <artifactId>java-multi-modules</artifactId>
        <groupId>com.mkyong.multi</groupId>
        <version>1.0</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

	<!-- password-md5 info -->
    <groupId>com.mkyong.password</groupId>
    <artifactId>password-md5</artifactId>
    <version>1.0</version>
    <packaging>jar</packaging>

    <dependencies>
        <dependency>
            <groupId>com.mkyong.password</groupId>
            <artifactId>password</artifactId>
            <version>1.0</version>
        </dependency>
    </dependencies>

</project>

2.4 In password-sha module.

password-sha/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">
		 
    <parent>
        <artifactId>java-multi-modules</artifactId>
        <groupId>com.mkyong.multi</groupId>
        <version>1.0</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

	<!-- password-sha info -->
    <groupId>com.mkyong.password</groupId>
    <artifactId>password-sha</artifactId>
    <version>1.0</version>
    <packaging>jar</packaging>

    <dependencies>
        <dependency>
            <groupId>com.mkyong.password</groupId>
            <artifactId>password</artifactId>
            <version>1.0</version>
        </dependency>
    </dependencies>

</project>

2.4 In web module.

web/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">

    <!-- this is a parent pom -->
    <parent>
        <groupId>com.mkyong.multi</groupId>
        <artifactId>java-multi-modules</artifactId>
        <version>1.0</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <!-- web project info -->
    <groupId>com.mkyong</groupId>
    <artifactId>web</artifactId>
    <version>1.0</version>
    <packaging>war</packaging>

    <dependencies>

		<!-- md5 or sha hashing -->
		
        <!-- md5 hash
        <dependency>
            <groupId>com.mkyong.password</groupId>
            <artifactId>password-md5</artifactId>
            <version>1.0</version>
        </dependency>
        -->

        <!-- sha -->
        <dependency>
            <groupId>com.mkyong.password</groupId>
            <artifactId>password-sha</artifactId>
            <version>1.0</version>
        </dependency>

    </dependencies>

</project>

3. Parent Project

3.1 Parent pom, those properties and dependencies (JDK 8, JUnit 5, Spring 5) are shared by all sub modules.

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.mkyong.multi</groupId>
    <artifactId>java-multi-modules</artifactId>
    <packaging>pom</packaging>
    <version>1.0</version>

    <properties>
        <!-- https://maven.apache.org/general.html#encoding-warning -->
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
        <junit.version>5.3.1</junit.version>
        <spring.version>5.1.0.RELEASE</spring.version>
    </properties>

    <modules>
        <module>web</module>
        <module>password</module>
        <module>password-sha</module>
        <module>password-md5</module>
    </modules>

    <dependencies>

        <!-- Spring DI for all modules -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <!-- unit test -->
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-engine</artifactId>
            <version>${junit.version}</version>
            <scope>test</scope>
        </dependency>
		
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-params</artifactId>
            <version>${junit.version}</version>
            <scope>test</scope>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-surefire-plugin</artifactId>
                <version>2.22.0</version>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-dependency-plugin</artifactId>
                <version>3.1.1</version>
            </plugin>
        </plugins>
    </build>
</project>

4. Password Module

4.1 A module containing only one interface.

4.2 POM file.

password/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">
    <parent>
        <artifactId>java-multi-modules</artifactId>
        <groupId>com.mkyong.multi</groupId>
        <version>1.0</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.mkyong.password</groupId>
    <artifactId>password</artifactId>
    <version>1.0</version>
    <packaging>jar</packaging>

</project>

4.3 An interface.

PasswordService.java

package com.mkyong.password;

public interface PasswordService {

    String hash(String input);

    String algorithm();

}

5. Password-md5 Module

5.1 Password module implementation.

5.2 POM file.

password-md5/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">
    <parent>
        <artifactId>java-multi-modules</artifactId>
        <groupId>com.mkyong.multi</groupId>
        <version>1.0</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <!-- password-md5 info -->
    <groupId>com.mkyong.password</groupId>
    <artifactId>password-md5</artifactId>
    <version>1.0</version>
    <packaging>jar</packaging>

    <dependencies>
        <dependency>
            <groupId>com.mkyong.password</groupId>
            <artifactId>password</artifactId>
            <version>1.0</version>
        </dependency>
    </dependencies>

</project>

5.3 MD5 hashing.

PasswordServiceImpl.java

package com.mkyong.password;

import org.springframework.stereotype.Service;

import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

@Service
public class PasswordServiceImpl implements PasswordService {

    @Override
    public String hash(String input) {
        return md5(input);
    }

    @Override
    public String algorithm() {
        return "md5";
    }

    private String md5(String input) {

        StringBuilder result = new StringBuilder();
        MessageDigest md;

        try {
            md = MessageDigest.getInstance("MD5");
            byte[] hashInBytes = md.digest(input.getBytes(StandardCharsets.UTF_8));

            for (byte b : hashInBytes) {
                result.append(String.format("%02x", b));
            }
        } catch (NoSuchAlgorithmException e) {
            throw new IllegalArgumentException(e);
        }

        return result.toString();
    }
}

5.4 Unit test.

TestPasswordService.java

package com.mkyong.password;

import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.CsvSource;

import static org.junit.jupiter.api.Assertions.assertEquals;

public class TestPasswordService {

    PasswordService passwordService;

    @BeforeEach
    void init() {
        passwordService = new PasswordServiceImpl();
    }

    @DisplayName("md5 -> hex")
    @ParameterizedTest
    @CsvSource({
            "123456, e10adc3949ba59abbe56e057f20f883e",
            "hello world, 5eb63bbbe01eeed093cb22bb8f5acdc3"
    })
    void testMd5hex(String input, String expected) {
        assertEquals(expected, passwordService.hash(input));
    }

}

6. Password-sha Module

6.1 Password module implementation.

6.2 POM file.

password-sha/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">
    <parent>
        <artifactId>java-multi-modules</artifactId>
        <groupId>com.mkyong.multi</groupId>
        <version>1.0</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.mkyong.password</groupId>
    <artifactId>password-sha</artifactId>
    <version>1.0</version>
    <packaging>jar</packaging>

    <properties>
        <commos.codec.version>1.11</commos.codec.version>
    </properties>

    <dependencies>

        <dependency>
            <groupId>commons-codec</groupId>
            <artifactId>commons-codec</artifactId>
            <version>${commos.codec.version}</version>
        </dependency>

        <dependency>
            <groupId>com.mkyong.password</groupId>
            <artifactId>password</artifactId>
            <version>1.0</version>
        </dependency>

    </dependencies>

</project>

6.3 SHA hashing with the Apache common codec library

PasswordServiceImpl.java

package com.mkyong.password;

import org.apache.commons.codec.digest.DigestUtils;
import org.springframework.stereotype.Service;

@Service
public class PasswordServiceImpl implements PasswordService {

    @Override
    public String hash(String input) {
        return DigestUtils.sha256Hex(input);
    }

    @Override
    public String algorithm() {
        return "sha256";
    }

}

6.4 Unit test.

TestPasswordService.java

package com.mkyong.password;

import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.CsvSource;

import static org.junit.jupiter.api.Assertions.assertEquals;

public class TestPasswordService {

    PasswordService passwordService;

    @BeforeEach
    void init() {
        passwordService = new PasswordServiceImpl();
    }

    @DisplayName("sha256 -> hex")
    @ParameterizedTest
    @CsvSource({
            "123456, 8d969eef6ecad3c29a3a629280e686cf0c3f5d5a86aff3ca12020c923adc6c92",
            "hello world, b94d27b9934d3e08a52e52d7da7dabfac484efe37a5380ee9088f7ace2efcde9"
    })
    void testSha256hex(String input, String expected) {
        assertEquals(expected, passwordService.hash(input));
    }

}

7. Web Module

7.1 A Spring MCV + thymeleaf web application, hash an input with a md5 or sha algorithm.

7.2 POM file.

web/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">

    <!-- this is a parent pom -->
    <parent>
        <groupId>com.mkyong.multi</groupId>
        <artifactId>java-multi-modules</artifactId>
        <version>1.0</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <!-- web project info -->
    <groupId>com.mkyong</groupId>
    <artifactId>web</artifactId>
    <version>1.0</version>
    <packaging>war</packaging>

    <properties>
        <thymeleaf.version>3.0.10.RELEASE</thymeleaf.version>
    </properties>

    <dependencies>

        <!-- md5 hash
        <dependency>
            <groupId>com.mkyong.password</groupId>
            <artifactId>password-md5</artifactId>
            <version>1.0</version>
        </dependency>
        -->

        <!-- sha -->
        <dependency>
            <groupId>com.mkyong.password</groupId>
            <artifactId>password-sha</artifactId>
            <version>1.0</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <!-- logging , spring 5 no more bridge, thanks spring-jcl -->
        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-classic</artifactId>
            <version>1.2.3</version>
        </dependency>

        <!-- need this for unit test -->
        <dependency>
            <groupId>org.hamcrest</groupId>
            <artifactId>hamcrest-library</artifactId>
            <version>1.3</version>
            <scope>test</scope>
        </dependency>

        <!-- servlet api -->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.1.0</version>
            <scope>provided</scope>
        </dependency>

        <!-- thymeleaf view -->
        <dependency>
            <groupId>org.thymeleaf</groupId>
            <artifactId>thymeleaf</artifactId>
            <version>${thymeleaf.version}</version>
        </dependency>

        <dependency>
            <groupId>org.thymeleaf</groupId>
            <artifactId>thymeleaf-spring5</artifactId>
            <version>${thymeleaf.version}</version>
        </dependency>

    </dependencies>

    <build>
        <finalName>java-web-project</finalName>
        <plugins>

            <plugin>
                <groupId>org.eclipse.jetty</groupId>
                <artifactId>jetty-maven-plugin</artifactId>
                <version>9.4.12.v20180830</version>
            </plugin>

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

        </plugins>
    </build>

</project>

7.3 Web module dependency

Terminal

$ mvn -pl web dependency:tree

[INFO] com.mkyong:web:war:1.0
[INFO] +- com.mkyong.password:password-sha:jar:1.0:compile
[INFO] |  +- commons-codec:commons-codec:jar:1.11:compile
[INFO] |  \- com.mkyong.password:password:jar:1.0:compile
[INFO] +- org.springframework:spring-webmvc:jar:5.1.0.RELEASE:compile
[INFO] |  +- org.springframework:spring-aop:jar:5.1.0.RELEASE:compile
[INFO] |  +- org.springframework:spring-beans:jar:5.1.0.RELEASE:compile
[INFO] |  +- org.springframework:spring-core:jar:5.1.0.RELEASE:compile
[INFO] |  |  \- org.springframework:spring-jcl:jar:5.1.0.RELEASE:compile
[INFO] |  +- org.springframework:spring-expression:jar:5.1.0.RELEASE:compile
[INFO] |  \- org.springframework:spring-web:jar:5.1.0.RELEASE:compile
[INFO] +- org.springframework:spring-test:jar:5.1.0.RELEASE:compile
[INFO] +- ch.qos.logback:logback-classic:jar:1.2.3:compile
[INFO] |  +- ch.qos.logback:logback-core:jar:1.2.3:compile
[INFO] |  \- org.slf4j:slf4j-api:jar:1.7.25:compile
[INFO] +- org.hamcrest:hamcrest-library:jar:1.3:test
[INFO] |  \- org.hamcrest:hamcrest-core:jar:1.3:test
[INFO] +- javax.servlet:javax.servlet-api:jar:3.1.0:provided
[INFO] +- org.thymeleaf:thymeleaf:jar:3.0.10.RELEASE:compile
[INFO] |  +- ognl:ognl:jar:3.1.12:compile
[INFO] |  |  \- org.javassist:javassist:jar:3.20.0-GA:compile
[INFO] |  +- org.attoparser:attoparser:jar:2.0.5.RELEASE:compile
[INFO] |  \- org.unbescape:unbescape:jar:1.1.6.RELEASE:compile
[INFO] +- org.thymeleaf:thymeleaf-spring5:jar:3.0.10.RELEASE:compile
[INFO] +- org.springframework:spring-context:jar:5.1.0.RELEASE:compile
[INFO] +- org.junit.jupiter:junit-jupiter-engine:jar:5.3.1:test
[INFO] |  +- org.apiguardian:apiguardian-api:jar:1.0.0:test
[INFO] |  +- org.junit.platform:junit-platform-engine:jar:1.3.1:test
[INFO] |  |  +- org.junit.platform:junit-platform-commons:jar:1.3.1:test
[INFO] |  |  \- org.opentest4j:opentest4j:jar:1.1.1:test
[INFO] |  \- org.junit.jupiter:junit-jupiter-api:jar:5.3.1:test
[INFO] \- org.junit.jupiter:junit-jupiter-params:jar:5.3.1:test
[INFO] ------------------------------------------------------------------------

7.4 Spring stuff, integrate thymeleaf and configuration.

SpringConfig.java

package com.mkyong.web.config;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
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.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import org.thymeleaf.spring5.SpringTemplateEngine;
import org.thymeleaf.spring5.templateresolver.SpringResourceTemplateResolver;
import org.thymeleaf.spring5.view.ThymeleafViewResolver;
import org.thymeleaf.templatemode.TemplateMode;

@EnableWebMvc
@Configuration
@ComponentScan({"com.mkyong"})
public class SpringConfig implements WebMvcConfigurer {

    @Autowired
    private ApplicationContext applicationContext;

    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/resources/**")
                .addResourceLocations("/resources/");
    }

    @Bean
    public SpringResourceTemplateResolver templateResolver() {
        SpringResourceTemplateResolver templateResolver = new SpringResourceTemplateResolver();
        templateResolver.setApplicationContext(this.applicationContext);
        templateResolver.setPrefix("/WEB-INF/views/");
        templateResolver.setSuffix(".html");
        templateResolver.setTemplateMode(TemplateMode.HTML);
        templateResolver.setCacheable(true);
        return templateResolver;
    }

    @Bean
    public SpringTemplateEngine templateEngine() {
        SpringTemplateEngine templateEngine = new SpringTemplateEngine();
        templateEngine.setTemplateResolver(templateResolver());
        templateEngine.setEnableSpringELCompiler(true);
        return templateEngine;
    }

    @Bean
    public ThymeleafViewResolver viewResolver() {
        ThymeleafViewResolver viewResolver = new ThymeleafViewResolver();
        viewResolver.setTemplateEngine(templateEngine());
        return viewResolver;
    }

}
WebInitializer.java

package com.mkyong.web;

import com.mkyong.web.config.SpringConfig;
import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;

public class WebInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {

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

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

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

}
WelcomeController.java

package com.mkyong.web.controller;

import com.mkyong.password.PasswordService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;

@Controller
public class WelcomeController {

    private final Logger logger = LoggerFactory.getLogger(WelcomeController.class);

    @Autowired
    private PasswordService passwordService;

    @GetMapping("/")
    public String welcome(@RequestParam(name = "query",
            required = false, defaultValue = "123456") String query, Model model) {

        logger.debug("Welcome to mkyong.com... Query : {}", query);

        model.addAttribute("query", query);
        model.addAttribute("hash", passwordService.hash(query));
        model.addAttribute("algorithm", passwordService.algorithm());

        return "index";
    }

}

7.5 Unit Test for Spring MVC.

TestWelcome.java

package com.mkyong.web;

import com.mkyong.web.config.SpringConfig;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.junit.jupiter.web.SpringJUnitWebConfig;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.test.web.servlet.setup.MockMvcBuilders;
import org.springframework.web.context.WebApplicationContext;

import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.*;

@SpringJUnitWebConfig(SpringConfig.class)
@DisplayName("Test Spring MVC default view")
public class TestWelcome {

    private MockMvc mockMvc;

    @Autowired
    private WebApplicationContext webAppContext;

    @BeforeEach
    public void setup() {
        mockMvc = MockMvcBuilders.webAppContextSetup(webAppContext).build();
    }

    @Test
    public void testDefault() throws Exception {

        this.mockMvc.perform(
                get("/"))
                .andExpect(status().isOk())
                .andExpect(view().name("index"))
                .andExpect(model().attribute("query", "123456"));
        //.andExpect(model().attribute("sha256", "8d969eef6ecad3c29a3a629280e686cf0c3f5d5a86aff3ca12020c923adc6c92"))
        //.andExpect(model().attribute("md5", "e10adc3949ba59abbe56e057f20f883e"));

    }

}

7.6 Thymeleaf view.

index.html

<!DOCTYPE HTML>
<html xmlns:th="http://www.thymeleaf.org">
<body>
<h1 th:text="'Input : ' + ${query}"/>
<h1 th:text="'Algorithm : ' + ${algorithm}"/>
<h3 th:text="${hash}" />
</body>
</html>

Done.

8. Demo

8.1 In parent project, uses the standard mvn compile to compile all the modules, Maven will decide the build order.

Terminal

$ mvn compile 

[INFO] Reactor Summary:
[INFO]
[INFO] java-multi-modules 1.0 ............................. SUCCESS [  0.007 s]
[INFO] password ........................................... SUCCESS [  0.539 s]
[INFO] password-sha ....................................... SUCCESS [  0.038 s]
[INFO] web ................................................ SUCCESS [  0.080 s]
[INFO] password-md5 1.0 ................................... SUCCESS [  0.035 s]
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 0.822 s
[INFO] Finished at: 2018-10-23T15:32:21+08:00
[INFO] ------------------------------------------------------------------------

8.2 Install all the modules into the local repository.

Terminal

$ mvn install 

8.3 Compiles the web module only (Maven will find the password module dependency from the local repository, that's why we need the mvn install

Terminal

$ mvn -pl web compile 

8.4 Alternatively, add -am to compile the web module and also its dependency modules (password-sha and password).

Terminal

$ mvn -am -pl web compile

[INFO] Scanning for projects...
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Build Order:
[INFO]
[INFO] java-multi-modules                                                 [pom]
[INFO] password                                                           [jar]
[INFO] password-sha                                                       [jar]
[INFO] web                                                                [war]

......

[INFO] Reactor Summary:
[INFO]
[INFO] java-multi-modules 1.0 ............................. SUCCESS [  0.009 s]
[INFO] password ........................................... SUCCESS [  0.534 s]
[INFO] password-sha ....................................... SUCCESS [  0.036 s]
[INFO] web 1.0 ............................................ SUCCESS [  0.077 s]
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 0.780 s
[INFO] Finished at: 2018-10-23T15:36:16+08:00
[INFO] ------------------------------------------------------------------------

8.5 Test the web module with mvn -pl web jetty:run command.

Terminal

$ mvn install

$ mvn -pl web jetty:run

//...
[INFO] 1 Spring WebApplicationInitializers detected on classpath
[INFO] DefaultSessionIdManager workerName=node0
[INFO] No SessionScavenger set, using defaults
[INFO] node0 Scavenging every 600000ms
[INFO] Started ServerConnector@40a8a26f{HTTP/1.1,[http/1.1]}{0.0.0.0:8080}
[INFO] Started @6398ms
[INFO] Started Jetty Server

8.6 http://localhost:8080

8.7 http://localhost:8080/?query=mkyong

8.8 Update to md5 algorithm. Restart the Jetty server.

web/pom.xml

		<!-- md5 hash -->
        <dependency>
            <groupId>com.mkyong.password</groupId>
            <artifactId>password-md5</artifactId>
            <version>1.0</version>
        </dependency>
        
        <!-- sha
        <dependency>
            <groupId>com.mkyong.password</groupId>
            <artifactId>password-sha</artifactId>
            <version>1.0</version>
        </dependency>
        -->

8.9 http://localhost:8080/?query=mkyong

Download Source Code

$ git clone https://github.com/mkyong/maven-examples.git
$ cd java-multi-modules
$ mvn install
$ mvn -pl web jetty:run

References

  1. Tutorial: Thymeleaf + Spring
  2. Serving Web Content with Spring MVC
  3. A Multi-Module Project
  4. Spring IO - Creating a Multi Module Project
  5. Multi-module project builds with Maven and Gradle
  6. Maven – How to create a Java project
  7. Maven – How to create a Java web application project

About the Author

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mkyong
Founder of Mkyong.com, love Java and open source stuff. Follow him on Twitter. If you like my tutorials, consider make a donation to these charities.

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bumbleeexxxJianfeiMazen KhalilAlex Abloodelo Recent comment authors
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Mazen Khalil
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Mazen Khalil

Great efforts! But you didn’t mention about the best practices for releasing such kind of projects and dealing with the repository. as the whole project with its submodules are located in single repository, how do you mange releases of different sub module versions (e.g. a bug in password-sha module will result to password-sha:2.0 module). Considering big project having concurrent sprints and different teams involved. In another words, how do you commit that to git repository and when do you mark it as tagged?

elo
Guest
elo

hi, I have issues with the install, I have this error: ——————————————————————————- Test set: com.mkyong.web.TestWelcome ——————————————————————————- Tests run: 1, Failures: 0, Errors: 1, Skipped: 0, Time elapsed: 6.754 s <<< FAILURE! – in com.mkyong.web.TestWelcome testDefault Time elapsed: 4.125 s <<< ERROR! org.springframework.web.util.NestedServletException: Request processing failed; nested exception is org.thymeleaf.exceptions.TemplateInputException: An error happened during template parsing (template: "ServletContext resource [/WEB-INF/views/index.html]") at com.mkyong.web.TestWelcome.testDefault(TestWelcome.java:37) Caused by: org.thymeleaf.exceptions.TemplateInputException: An error happened during template parsing (template: "ServletContext resource [/WEB-INF/views/index.html]") at com.mkyong.web.TestWelcome.testDefault(TestWelcome.java:37) Caused by: java.io.FileNotFoundException: Could not open ServletContext resource [/WEB-INF/views/index.html] at com.mkyong.web.TestWelcome.testDefault(TestWelcome.java:37) I took the files from git, and indeed there is no WEB-INF directory… Read more »

Alex Ablood
Guest
Alex Ablood

Same here, did you figure this out? That .html whatever cause maven to fail build.

bumbleeexxx
Guest
bumbleeexxx

yes it is missing and i wonder why nobody answers your question. You should only create the file index.html under the directory java-multi-modules/web/src/main/webapp/WEB-INF/views/index.html

you can copy the content of the file from above

Jianfei
Guest
Jianfei

It’s really a good example !
I did every thing you showed here, but I still cannot use the interface from the dependency module.
You could check this question if you are interested : https://stackoverflow.com/questions/57866901/cannot-use-interface-or-class-from-another-local-dependency-module

Thanks again for your example!