我是Spring Boot开发的新手，请帮我解决以下错误
目录结构(仅包括重要文件的结构)
src
-main
-java
-com.example.handlingformsubmission
-Greeting.java
-GreetingController.java
-HandlingFormSubmissionApplication.java
-resources
-templates
-greeting.html
-result.html
-application.properties
-test
-java
-com.example.handlingformsubmission
-HandlingFormSubmissionApplicationTest.java
-build.gradle
在执行期间，在浏览器上运行该错误时遇到了此错误
Whitelabel Error Page
This application has no explicit mapping for /error, so you are seeing this as a fallback.
Wed Mar 11 19:08:44 IST 2020
There was an unexpected error (type=Not Found, status=404).
No message available
当我终止或停止申请时
Execution failed for task ':HandlingFormSubmissionApplication.main()'.
> Process 'command '/usr/lib/jvm/java-11-amazon-corretto/bin/java'' finished with non-zero exit value 143
目前我正在使用springboot版本2.2.2
这是我的代码
build.gradle
plugins {
id 'org.springframework.boot' version '2.2.2.RELEASE'
id 'io.spring.dependency-management' version '1.0.8.RELEASE'
id 'java'
id 'war'
}
group = 'com.example'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = '1.8'
repositories {
mavenCentral()
}
dependencies {
implementation 'org.springframework.boot:spring-boot-starter-thymeleaf'
implementation 'org.springframework.boot:spring-boot-starter-web'
testImplementation('org.springframework.boot:spring-boot-starter-test') {
exclude group: 'org.junit.vintage', module: 'junit-vintage-engine'
}
}
test {
useJUnitPlatform()
}
HandlingFormSubmissionApplication.java
package com.example.handlingformsubmission;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;
@ComponentScan(basePackages = {"com.example.handlingformsubmission.greeting"})
@SpringBootApplication
public class HandlingFormSubmissionApplication {
public static void main(String[] args) {
SpringApplication.run(HandlingFormSubmissionApplication.class, args);
}
}
GreetingController.java
package com.example.handlingformsubmission.greeting;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.PostMapping;
@Controller
public class GreetingController {
@GetMapping("/greeting")
public String greetingForm(Model model) {
model.addAttribute("greeting", new Greeting());
return "greeting";
}
@PostMapping("/greeting")
public String greetingSubmit(@ModelAttribute Greeting greeting, Model model) {
model.addAttribute("greeting", greeting);
return "result";
}
}
application.properties
server.port=8000
greeting.html
<!DOCTYPE HTML>
<html xmlns:th="https://www.thymeleaf.org">
<head>
<title>Getting Started: Handling Form Submission</title>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
</head>
<body>
<h1>Form</h1>
<form action="#" th:action="@{/greeting}" th:object="${greeting}" method="post">
<p>Id: <input type="text" th:field="*{id}" /></p>
<p>Message: <input type="text" th:field="*{content}" /></p>
<p><input type="submit" value="Submit" /> <input type="reset" value="Reset" /></p>
</form>
</body>
</html>
result.html
<!DOCTYPE HTML>
<html xmlns:th="https://www.thymeleaf.org">
<head>
<title>Getting Started: Handling Form Submission</title>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
</head>
<body>
<h1>Result</h1>
<p th:text="'id: ' + ${greeting.id}" />
<p th:text="'content: ' + ${greeting.content}" />
<a href="/greeting">Submit another message</a>
</body>
</html>
最佳答案
该问题未指定，但我猜您要执行GET http://localhost:8000/greeting
我不会修复您的表单，但是 404 可以通过修复@ComponentScan来解决，例如...
// wrong: '.greeting' excludes the 'GreetingController'
@ComponentScan(basePackages = {"com.example.handlingformsubmission.greeting"})
// fixed: specifies a valid path that includes the controller
@ComponentScan(basePackages = {"com.example.handlingformsubmission"})
解决此问题后，您将可以继续解决下一个问题:
There was an unexpected error (type=Internal Server Error, status=500). An error happened during template parsing (template: "class path resource [templates/greeting.html]")
您还可以通过完全删除
@ComponentScan来解决此问题-在此初始方案中不需要。
关于spring-boot - 为Spring-boot应用程序获取whitelabel错误，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/60623300/