Whitelabel Error无法扫描控制器的页面- Spring boot- jsp

Question

我正在学习如何通过春季启动构建web应用程序。
当我尝试使用控制器使用@Controller来显示jsp页面时，"白标签错误页面"。这个应用程序没有对/Error的显式映射，所以您可以将其视为一个后备方案。显示。

我考虑过问题是否与组件扫描有关，但是当我将@Controller更改为@RestController时，网页可以显示我键入的字符串。

我想问为什么在使用@Controller时不能扫描bean，以及我如何解决这个问题。

这是控制器类

package com.lms.controllers;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.GetMapping;

@Controller
public class MainController {

@GetMapping("h")
public String init(ModelMap Model) {
return "index";
}
}

应用程序属性

spring.mvc.view.prefix = /WEB-INF/views/
spring.mvc.view.suffix = .jsp
spring.datasource.url = jdbc:mysql://localhost:3306/mydb?useSSL=false
spring.datasource.username = root
spring.datasource.password = 0000
#Allows Hibernate to generate SQL optimized for a particular DBMS
spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.MySQL5Dialect
spring.jpa.hibernate.ddl-auto = update
logging.level.org.hibernate.SQL = debug

xml文件

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.5.4</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.library</groupId>
<artifactId>library</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>LMS</name>
<description>Demo project for Spring Boot Library Management System</description>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>



<dependencies>
<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>

<!-- Persistance related -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>



<dependency>
<groupId> org.apache.tomcat.embed </groupId>
<artifactId> tomcat-embed-jasper </artifactId>
<scope> provided </scope>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
</dependency>
</dependencies>

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

日志

2021-08-22 02:55:47.719 DEBUG 17084 --- [nio-8080-exec-1] o.s.w.s.v.ContentNegotiatingViewResolver : Selected 'text/html' given [text/html, application/xhtml+xml, image/webp, image/apng, application/xml;q=0.9, application/signed-exchange;v=b3;q=0.9, */*;q=0.8]
2021-08-22 02:55:47.719 DEBUG 17084 --- [nio-8080-exec-1] o.s.web.servlet.view.JstlView            : View name 'index', model {}
2021-08-22 02:55:47.721 DEBUG 17084 --- [nio-8080-exec-1] o.s.web.servlet.view.JstlView            : Forwarding to [/WEB-INF/views/index.jsp]
2021-08-22 02:55:47.726 DEBUG 17084 --- [nio-8080-exec-1] o.j.s.OpenEntityManagerInViewInterceptor : Closing JPA EntityManager in OpenEntityManagerInViewInterceptor
2021-08-22 02:55:47.726 DEBUG 17084 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : Completed 404 NOT_FOUND
2021-08-22 02:55:47.727 DEBUG 17084 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : "ERROR" dispatch for GET "/error", parameters={}
2021-08-22 02:55:47.728 DEBUG 17084 --- [nio-8080-exec-1] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped to org.springframework.boot.autoconfigure.web.servlet.error.BasicErrorController#errorHtml(HttpServletRequest, HttpServletResponse)
2021-08-22 02:55:47.728 DEBUG 17084 --- [nio-8080-exec-1] o.j.s.OpenEntityManagerInViewInterceptor : Opening JPA EntityManager in OpenEntityManagerInViewInterceptor
2021-08-22 02:55:47.741 DEBUG 17084 --- [nio-8080-exec-1] o.s.w.s.v.ContentNegotiatingViewResolver : Selected 'text/html' given [text/html, text/html;q=0.8]
2021-08-22 02:55:47.744 DEBUG 17084 --- [nio-8080-exec-1] o.j.s.OpenEntityManagerInViewInterceptor : Closing JPA EntityManager in OpenEntityManagerInViewInterceptor
2021-08-22 02:55:47.744 DEBUG 17084 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : Exiting from "ERROR" dispatch, status 404

我想知道如果我把。jsp文件在错误的地方。这是我放置.jsp文件的地方。

输入图片描述

我已经被困好几个小时了。希望有人能帮我解决这个问题。

Answer 1

GetMapping的值错误。

修改为/h

也可以。改变:试试下面的代码来代替origin方法:

@GetMapping(“/h”)
public ModelAndView init() {
return new ModelAndView(“index”);
}