Maven：无法运行spring boot项目

Question

我正在尝试使用Spring Boot编写一个多模块Maven项目。但是很不幸，我无法使其成功运行，因此当我在服务器上运行Web模块时，它会在相应的Web页面上显示404错误。我的项目结构如下：

我不得不提到，我在Web模块上没有指向任何地方的“红色x”。我不知道是否有问题。在ui模块上，我已编写此代码

package com.sali.ui.commons;

import com.vaadin.annotations.Theme;
import com.vaadin.annotations.Title;
import com.vaadin.server.VaadinRequest;
import com.vaadin.spring.annotation.SpringUI;
import com.vaadin.ui.Label;
import com.vaadin.ui.UI;
import com.vaadin.ui.VerticalLayout;

@SpringUI(path=UniversMainUI.NAME)
@Title("U n i v e r s")
@Theme("valo")
public class UniversMainUI extends UI{

    public static final String NAME = "/ui";

    @Override
    protected void init(VaadinRequest request) {

        VerticalLayout rootLayout = new VerticalLayout();
        rootLayout.addComponent(new Label("Oh we have made it!"));
        setContent(rootLayout);

    }

}

Web模块pom看起来像这样：

<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>


  <artifactId>universeBySali-web</artifactId>
  <packaging>war</packaging>

   <parent>
    <groupId>org.springframework.boot</groupId>
     <artifactId>spring-boot-starter-parent</artifactId>
         <version>1.3.6.RELEASE</version>
         <relativePath/>
     </parent>

    <properties>
        <java.version>13.0.2</java.version>
     </properties>

    <dependencies>
        <dependency>
            <groupId>com.vaadin</groupId>
            <artifactId>vaadin-spring-boot-starter</artifactId>
            <version>15.0.0</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>com.sali</groupId>
            <artifactId>universeBySali-ui</artifactId>
            <version>0.0.1-SNAPSHOT</version>
        </dependency>
    </dependencies>

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

        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-war-plugin</artifactId>
            <configuration>
                <failOnMissingWebXml>false</failOnMissingWebXml>
            </configuration>
        </plugin>
    </plugins>
  </build>
</project> 

请帮助。我应该尽快进行此项目。