Maven - Как создать проект веб-приложения на Java

Maven - Как создать проект веб-приложения Java

В этом руководстве мы покажем вам, как использовать Maven для управления веб-проектом Java. В конце мы создадим веб-приложение Spring MVC, отображающее текущую дату на странице JSP.

Используемые технологии:

Maven 3.5.3
JDK 8
Весна 5.1.0. ВЫПУСК
Юнит 5
Logback 1.2.3
Jetty 9.4.x или Tomcat 8.5

1. Создайте веб-проект из шаблона Maven

Создайте веб-проект из шаблона Mavenmaven-archetype-webapp

mvn archetype:generate
    -DgroupId={project-packaging}
    -DartifactId={project-name}
    -DarchetypeArtifactId={maven-template}
    -DinteractiveMode=false

Например,

D:\>mvn archetype:generate -DgroupId=com.example.web -DartifactId=java-web-project -DarchetypeArtifactId=maven-archetype-webapp -DinteractiveMode=false

[INFO] Scanning for projects...
[INFO]
[INFO] ------------------< org.apache.maven:standalone-pom >-------------------
[INFO] Building Maven Stub Project (No POM) 1
[INFO] --------------------------------[ pom ]---------------------------------
[INFO]
[INFO] >>> maven-archetype-plugin:3.0.1:generate (default-cli) > generate-sources @ standalone-pom >>>
[INFO]
[INFO] <<< maven-archetype-plugin:3.0.1:generate (default-cli) < generate-sources @ standalone-pom <<<
[INFO]
[INFO]
[INFO] --- maven-archetype-plugin:3.0.1:generate (default-cli) @ standalone-pom ---
[INFO] Generating project in Batch mode
[INFO] ----------------------------------------------------------------------------
[INFO] Using following parameters for creating project from Old (1.x) Archetype: maven-archetype-webapp:1.0
[INFO] ----------------------------------------------------------------------------
[INFO] Parameter: basedir, Value: D:\
[INFO] Parameter: package, Value: com.example.web
[INFO] Parameter: groupId, Value: com.example.web
[INFO] Parameter: artifactId, Value: java-web-project
[INFO] Parameter: packageName, Value: com.example.web
[INFO] Parameter: version, Value: 1.0-SNAPSHOT
[INFO] project created from Old (1.x) Archetype in dir: D:\java-web-project
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 6.509 s
[INFO] Finished at: 2018-10-04T15:25:16+08:00
[INFO] ------------------------------------------------------------------------

Note
На самом деле, это необязательно для создания веб-проекта из веб-шаблона Maven. Вы всегда можете создать эти папки вручную с помощью классической командыmkdir.

2. Шаблон Maven

2.1 The following project directory structure will be created.

P.S Above figure is captured from IntelliJ IDEA, just ignore those IDE folders like .idea and `java-web-project.iml`

2.2 Review the generated pom.xml.

pom.xml


  4.0.0
  com.example.web
  java-web-project
  war
  1.0-SNAPSHOT
  java-web-project Maven Webapp
  http://maven.apache.org
  
    
      junit
      junit
      3.8.1
      test
    
  
  
    java-web-project

P.S The generated files are not much value, we will update all of them later. Сначала удалитеweb.xml, нам это не нужно.

3. Обновить POM

3.1 Update the pom.xml file, add dependencies for Spring MVC for web framework, JUnit for unit test, Jetty server to test the web project, and also some Maven configuration.

pom.xml


    4.0.0
    com.example.web
    java-web-project
    war
    1.0-SNAPSHOT
    java-web-project Maven Webapp
    http://maven.apache.org
    
        
        UTF-8
        1.8
        1.8
        5.1.0.RELEASE
    

    

        
            org.springframework
            spring-webmvc
            ${spring.version}
        

        
            org.springframework
            spring-test
            ${spring.version}
        

        
        
            ch.qos.logback
            logback-classic
            1.2.3
        

        
        
            org.junit.jupiter
            junit-jupiter-engine
            5.3.1
            test
        

        
        
            org.hamcrest
            hamcrest-library
            1.3
            test
        

        
        
            javax.servlet
            javax.servlet-api
            3.1.0
            provided
        

        
        
            javax.servlet
            jstl
            1.2
            provided
        

    
    
        java-web-project
        
            
            
                org.eclipse.jetty
                jetty-maven-plugin
                9.4.12.v20180830
            

            
            
                org.apache.maven.plugins
                maven-surefire-plugin
                2.22.0
            

            
            
                org.apache.maven.plugins
                maven-war-plugin
                3.2.2

3.2 Display the project dependencies.

D:\> mvn dependency:tree

...
[INFO] --- maven-dependency-plugin:2.8:tree (default-cli) @ java-web-project ---
[INFO] com.example.web:java-web-project:war:1.0-SNAPSHOT
[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-context: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.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.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] \- javax.servlet:jstl:jar:1.2:provided
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 0.931 s
[INFO] Finished at: 2018-10-08T15:55:08+08:00
[INFO] ------------------------------------------------------------------------

4. Spring MVC + JSP + LogBack

4.1 Create a few files to bootstrap Spring MVC web project.

SpringConfig.java

package com.example.web.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.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import org.springframework.web.servlet.view.InternalResourceViewResolver;
import org.springframework.web.servlet.view.JstlView;

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

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

    @Bean
    public InternalResourceViewResolver viewResolver() {
        InternalResourceViewResolver viewResolver
                = new InternalResourceViewResolver();
        viewResolver.setViewClass(JstlView.class);
        viewResolver.setPrefix("/WEB-INF/views/");
        viewResolver.setSuffix(".jsp");
        return viewResolver;
    }
}

WebInitializer.java

package com.example.web;

import com.example.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.example.web.controller;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;

import java.util.Date;

@Controller
public class WelcomeController {

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

    @GetMapping("/")
    public String index(Model model) {
        logger.debug("Welcome to example.com...");
        model.addAttribute("msg", getMessage());
        model.addAttribute("today", new Date());
        return "index";

    }

    private String getMessage() {
        return "Hello World";
    }

}

4.2 Move the index.jsp file into the WEB-INF folder, and update it

index.jsp

<%@ taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt"%>


${msg}
Today is

4.3 Logs to console.

logbacl.xml




    
        

            
                %d{yyyy-MM-dd HH:mm:ss} [%thread] %-5level %logger{36} - %msg%n

5. Модульный тест

Простой пример Spring MVC 5 + JUnit 5.

TestWelcome.java

package com.example.web;

import com.example.web.config.SpringConfig;
import org.junit.jupiter.api.BeforeEach;
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.MockMvcResultHandlers.print;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.*;

@SpringJUnitWebConfig(SpringConfig.class)
public class TestWelcome {

    private MockMvc mockMvc;

    @Autowired
    private WebApplicationContext webAppContext;

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

    @Test
    public void testWelcome() throws Exception {

        this.mockMvc.perform(
                get("/"))
                .andDo(print())
                .andExpect(status().isOk())
                .andExpect(view().name("index"))
                .andExpect(forwardedUrl("/WEB-INF/views/index.jsp"))
                .andExpect(model().attribute("msg", "Hello World"));
    }

}

6. Структура каталогов

Просмотрите окончательные файлы и структуру каталогов.

Прочтите этоMaven Standard Directory Layout.

7. Demo

7.1 Test the web project with Jetty web server - mvn jetty:run

D:\> mvn jetty:run

[INFO] webAppSourceDirectory not set. Trying src\main\webapp
[INFO] Reload Mechanic: automatic
[INFO] nonBlocking:false
[INFO] Classes = D:\java-web-project\target\classes
[INFO] Configuring Jetty for project: java-web-project Maven Webapp
[INFO] Logging initialized @4821ms to org.eclipse.jetty.util.log.Slf4jLog
[INFO] Context path = /
[INFO] Tmp directory = D:\java-web-project\target\tmp
[INFO] Web defaults = org/eclipse/jetty/webapp/webdefault.xml
[INFO] Web overrides =  none
[INFO] web.xml file = null
[INFO] Webapp directory = D:\java-web-project\src\main\webapp
[INFO] jetty-9.4.12.v20180830; built: 2018-08-30T13:59:14.071Z; git: 27208684755d94a92186989f695db2d7b21ebc51; jvm 10.0.1+10

...

[INFO] 1 Spring WebApplicationInitializers detected on classpath
2018-10-08 15:11:50 [main] DEBUG com.example.web.WebInitializer - No ContextLoaderListener registered, as createRootApplicationContext() did not return an application context
[INFO] DefaultSessionIdManager workerName=node0
[INFO] No SessionScavenger set, using defaults
[INFO] node0 Scavenging every 660000ms
[INFO] Initializing Spring DispatcherServlet 'dispatcher'
[INFO] Started o.e.j.m.p.JettyWebAppContext@68a78f3c{/,file:///D:/java-web-project/src/main/webapp/,AVAILABLE}{file:///D:/java-web-project/src/main/webapp/}
[INFO] Started ServerConnector@3355168{HTTP/1.1,[http/1.1]}{0.0.0.0:8080}
[INFO] Started @6271ms
[INFO] Started Jetty Server
2018-10-08 15:12:01 [qtp1373051324-19] DEBUG c.m.web.controller.WelcomeController - Welcome to example.com...

7.2 Access it via http://localhost:8080/

P.S CTRL + C to stop the Jetty web server.

8. развертывание

8.1 mvn package to generate a WAR file for deployment.

D:\> mvn package

...

[INFO] Packaging webapp
[INFO] Assembling webapp [java-web-project] in [D:\java-web-project\target\java-web-project]
[INFO] Processing war project
[INFO] Copying webapp resources [D:\java-web-project\src\main\webapp]
[INFO] Webapp assembled in [89 msecs]
[INFO] Building war: D:\java-web-project\target\java-web-project.war
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 3.844 s
[INFO] Finished at: 2018-10-08T15:31:12+08:00
[INFO] ------------------------------------------------------------------------

Каталог по умолчанию для сгенерированной WAR -target/finalName. Готово.

Скачать исходный код

$ git clone https://github.com/example/maven-examples.git
$ cd java-web-project
$ mvn jetty:run

http://localhost:8080

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