SpringUI不能被解析爲一個類型

Question

繼this教程中，我試圖安裝一個Maven項目，Spring-boot和Vaadin。

我在@SpringUI註釋越來越SpringUI cannot be resolved to a type錯誤。

的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.example</groupId> 
    <artifactId>demo</artifactId> 
    <version>0.0.1-SNAPSHOT</version> 
    <packaging>war</packaging> 

    <name>demo</name> 
    <description>Demo project for Spring Boot</description> 

    <parent> 
     <groupId>org.springframework.boot</groupId> 
     <artifactId>spring-boot-starter-parent</artifactId> 
     <version>1.5.4.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> 
     <vaadin.version>8.0.5</vaadin.version> 
    </properties> 

    <dependencies> 
     <dependency> 
      <groupId>com.vaadin</groupId> 
      <artifactId>vaadin-spring-boot-starter</artifactId> 
     </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> 
      <scope>test</scope> 
     </dependency> 
    </dependencies> 

    <dependencyManagement> 
     <dependencies> 
      <dependency> 
       <groupId>com.vaadin</groupId> 
       <artifactId>vaadin-bom</artifactId> 
       <version>${vaadin.version}</version> 
       <type>pom</type> 
       <scope>import</scope> 
      </dependency> 
     </dependencies> 
    </dependencyManagement> 

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


</project> 

DemoApplication.java：

package com.example.demo; 

import org.springframework.boot.SpringApplication; 
import org.springframework.boot.autoconfigure.SpringBootApplication; 

@SpringBootApplication 
public class DemoApplication { 

    public static void main(String[] args) { 
     SpringApplication.run(DemoApplication.class, args); 
    } 
} 

TodoUI.java：

package com.example.demo; 

import com.vaadin.server.VaadinRequest; 
import com.vaadin.ui.UI; 
import com.vaadin.spring.annotation.SpringUI; 

@SpringUI(path = "/myPath") // SpringUI cannot be resolved to a type | WHY? 
public class TodoUI extends UI { 
    private static final long serialVersionUID = -1463774427806228298L; 

    @Override 
    protected void init(VaadinRequest request) { 

    } 

} 

我在這裏做錯了什麼？

Answer 1

我檢查你的源代碼，一切看起來不錯，所以可能一些配置錯誤或者類似的東西。

但是，要獲得工作項目，您可以從視頻準備下載項目在GitHub上：https://github.com/vaadin-marcus/spring-boot-todo和導入。並且可以比較，你的錯誤在哪裏。