前提・実現したいこと
Spring Bootで初めて開発を行っており、動作確認のために"Hello World"を表示させたいがエラーが表示される。
発生している問題・エラーメッセージ
:: Spring Boot :: (v2.2.7.RELEASE)
2020-05-16 11:57:08.582 ERROR 8084 --- [ restartedMain] o.a.c.c.C.[Tomcat].[localhost].[/] : Exception sending context initialized event to listener instance of class [com.vaadin.flow.spring.VaadinServletContextInitializer$DevModeServletContextListener]
java.lang.RuntimeException: Unable to initialize Vaadin DevModeHandler
at com.vaadin.flow.spring.VaadinServletContextInitializer$DevModeServletContextListener.contextInitialized(VaadinServletContextInitializer.java:349) ~[vaadin-spring-12.1.4.jar:na]
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4688) [tomcat-embed-core-9.0.34.jar:9.0.34]
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5151) [tomcat-embed-core-9.0.34.jar:9.0.34]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) [tomcat-embed-core-9.0.34.jar:9.0.34]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1384) [tomcat-embed-core-9.0.34.jar:9.0.34]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1374) [tomcat-embed-core-9.0.34.jar:9.0.34]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) [na:1.8.0_202]
at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) [tomcat-embed-core-9.0.34.jar:9.0.34]
at java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:134) [na:1.8.0_202]
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:909) [tomcat-embed-core-9.0.34.jar:9.0.34]
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:841) [tomcat-embed-core-9.0.34.jar:9.0.34]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) [tomcat-embed-core-9.0.34.jar:9.0.34]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1384) [tomcat-embed-core-9.0.34.jar:9.0.34]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1374) [tomcat-embed-core-9.0.34.jar:9.0.34]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) [na:1.8.0_202]
at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) [tomcat-embed-core-9.0.34.jar:9.0.34]
at java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:134) [na:1.8.0_202]
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:909) [tomcat-embed-core-9.0.34.jar:9.0.34]
at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:262) [tomcat-embed-core-9.0.34.jar:9.0.34]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) [tomcat-embed-core-9.0.34.jar:9.0.34]
at org.apache.catalina.core.StandardService.startInternal(StandardService.java:421) [tomcat-embed-core-9.0.34.jar:9.0.34]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) [tomcat-embed-core-9.0.34.jar:9.0.34]
at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:930) [tomcat-embed-core-9.0.34.jar:9.0.34]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) [tomcat-embed-core-9.0.34.jar:9.0.34]
at org.apache.catalina.startup.Tomcat.start(Tomcat.java:468) [tomcat-embed-core-9.0.34.jar:9.0.34]
at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.initialize(TomcatWebServer.java:106) [spring-boot-
Caused by: javax.servlet.ServletException: com.vaadin.flow.server.ExecutionFailedException:
該当のソースコード
以下がControllerクラスです。
Java
1package com.example.demo.trySpring; 2 3import org.springframework.stereotype.Controller; 4import org.springframework.web.bind.annotation.GetMapping; 5 6@Controller 7public class HelloController { 8 9 @GetMapping("/hello") 10 public String getHello() { 11 return "hello"; 12 } 13} 14
以下がHTMLです。
HTML
1<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 2<html xmlns:th="http://www.thymeleaf.org"> 3<head> 4<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"></meta> 5<title>Hello World</title> 6</head> 7<body> 8<h1>Hello World</h1> 9</body> 10</html> 11
以下がpom.xmlです。
xml
1<?xml version="1.0" encoding="UTF-8"?> 2<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 3 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd"> 4 <modelVersion>4.0.0</modelVersion> 5 <parent> 6 <groupId>org.springframework.boot</groupId> 7 <artifactId>spring-boot-starter-parent</artifactId> 8 <version>2.2.7.RELEASE</version> 9 <relativePath/> <!-- lookup parent from repository --> 10 </parent> 11 <groupId>com.example</groupId> 12 <artifactId>SpringSample</artifactId> 13 <version>0.0.1-SNAPSHOT</version> 14 <name>SpringSample</name> 15 <description>Demo project for Spring Boot</description> 16 17 <properties> 18 <java.version>1.8</java.version> 19 <vaadin.version>14.1.28</vaadin.version> 20 </properties> 21 22 <dependencies> 23 <dependency> 24 <groupId>org.springframework.boot</groupId> 25 <artifactId>spring-boot-starter-data-jdbc</artifactId> 26 </dependency> 27 <dependency> 28 <groupId>org.springframework.boot</groupId> 29 <artifactId>spring-boot-starter-jdbc</artifactId> 30 </dependency> 31 <dependency> 32 <groupId>org.springframework.boot</groupId> 33 <artifactId>spring-boot-starter-jersey</artifactId> 34 </dependency> 35 <dependency> 36 <groupId>org.springframework.boot</groupId> 37 <artifactId>spring-boot-starter-thymeleaf</artifactId> 38 </dependency> 39 <dependency> 40 <groupId>org.springframework.boot</groupId> 41 <artifactId>spring-boot-starter-web</artifactId> 42 </dependency> 43 <dependency> 44 <groupId>org.springframework.boot</groupId> 45 <artifactId>spring-boot-starter-web-services</artifactId> 46 </dependency> 47 <dependency> 48 <groupId>org.springframework.boot</groupId> 49 <artifactId>spring-boot-starter-webflux</artifactId> 50 </dependency> 51 <dependency> 52 <groupId>org.springframework.boot</groupId> 53 <artifactId>spring-boot-starter-websocket</artifactId> 54 </dependency> 55 <dependency> 56 <groupId>com.vaadin</groupId> 57 <artifactId>vaadin-spring-boot-starter</artifactId> 58 </dependency> 59 60 <dependency> 61 <groupId>org.springframework.boot</groupId> 62 <artifactId>spring-boot-devtools</artifactId> 63 <scope>runtime</scope> 64 <optional>true</optional> 65 </dependency> 66 <dependency> 67 <groupId>com.h2database</groupId> 68 <artifactId>h2</artifactId> 69 <scope>runtime</scope> 70 </dependency> 71 <dependency> 72 <groupId>org.projectlombok</groupId> 73 <artifactId>lombok</artifactId> 74 <optional>true</optional> 75 </dependency> 76 <dependency> 77 <groupId>org.springframework.boot</groupId> 78 <artifactId>spring-boot-starter-test</artifactId> 79 <scope>test</scope> 80 <exclusions> 81 <exclusion> 82 <groupId>org.junit.vintage</groupId> 83 <artifactId>junit-vintage-engine</artifactId> 84 </exclusion> 85 </exclusions> 86 </dependency> 87 <dependency> 88 <groupId>io.projectreactor</groupId> 89 <artifactId>reactor-test</artifactId> 90 <scope>test</scope> 91 </dependency> 92 </dependencies> 93 94 <dependencyManagement> 95 <dependencies> 96 <dependency> 97 <groupId>com.vaadin</groupId> 98 <artifactId>vaadin-bom</artifactId> 99 <version>${vaadin.version}</version> 100 <type>pom</type> 101 <scope>import</scope> 102 </dependency> 103 </dependencies> 104 </dependencyManagement> 105 106 <build> 107 <plugins> 108 <plugin> 109 <groupId>org.springframework.boot</groupId> 110 <artifactId>spring-boot-maven-plugin</artifactId> 111 </plugin> 112 </plugins> 113 </build> 114 115</project> 116
補足情報(FW/ツールのバージョンなど)
ここにより詳細な情報を記載してください。
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