BeanCreationException：创建名称为“servletComponentRegisteringPostProcessor”的 bean 时出错：提供的 bean 实例化失败

Question

在从 Youtube 视频学习 java web servlet 时，我遇到了这个错误，而教程却没有。这仍然是本教程的开始，我也不知道 spring 是如何工作的。我刚刚学会了如何通过将 war 文件放入 tomcat 文件夹中的 webapps 文件夹来手动部署，之后是如何通过借用/使用嵌入式 tomcat spring boot 自动部署（这不是 spring 教程，所以他对此没有解释太多） .

只有两个文件

1. BelajarServletApp.java

package yt.pzn.servlet;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.ServletComponentScan;

@ServletComponentScan
@SpringBootApplication
public class BelajarServletApp {

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

2. HelloServlet.java 文件

package yt.pzn.servlet;

import jakarta.servlet.ServletException;
import jakarta.servlet.annotation.WebServlet;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;

import java.io.IOException;

@WebServlet(urlPatterns = {"/halo", "/bang"})
public class HelloServlet extends HttpServlet {

    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.getWriter().println("halo bang");
    }
}

这是我运行后说的。应该发生的情况是文件部署在本地主机端口 8080 上并且没有发生错误。这不是由使用的端口引起的吧？顺便说一句，端口 8080 是免费的。那么我该如何解决这个问题呢？这是由什么引起的？

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::                (v3.1.2)

2023-07-24T11:45:53.757+07:00  INFO 8752 --- [           main] yt.pzn.servlet.BelajarServletApp         : Starting BelajarServletApp using Java 17.0.7 with PID 8752 (C:\Coding Projects\belajar-java-web-servlet\target\classes started by USER in C:\Coding Projects\belajar-java-web-servlet)
2023-07-24T11:45:53.774+07:00  INFO 8752 --- [           main] yt.pzn.servlet.BelajarServletApp         : No active profile set, falling back to 1 default profile: "default"
2023-07-24T11:45:55.441+07:00  WARN 8752 --- [           main] s.c.a.AnnotationConfigApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'servletComponentRegisteringPostProcessor': Instantiation of supplied bean failed
2023-07-24T11:45:55.472+07:00  INFO 8752 --- [           main] .s.b.a.l.ConditionEvaluationReportLogger : 

Error starting ApplicationContext. To display the condition evaluation report re-run your application with 'debug' enabled.
2023-07-24T11:45:55.553+07:00 ERROR 8752 --- [           main] o.s.boot.SpringApplication               : Application run failed

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'servletComponentRegisteringPostProcessor': Instantiation of supplied bean failed
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.obtainFromSupplier(AbstractAutowireCapableBeanFactory.java:1220) ~[spring-beans-6.0.11.jar:6.0.11]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1158) ~[spring-beans-6.0.11.jar:6.0.11]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:560) ~[spring-beans-6.0.11.jar:6.0.11]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:520) ~[spring-beans-6.0.11.jar:6.0.11]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:326) ~[spring-beans-6.0.11.jar:6.0.11]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-6.0.11.jar:6.0.11]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:324) ~[spring-beans-6.0.11.jar:6.0.11]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:205) ~[spring-beans-6.0.11.jar:6.0.11]
    at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:199) ~[spring-context-6.0.11.jar:6.0.11]
    at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:771) ~[spring-context-6.0.11.jar:6.0.11]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:589) ~[spring-context-6.0.11.jar:6.0.11]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:734) ~[spring-boot-3.1.2.jar:3.1.2]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:436) ~[spring-boot-3.1.2.jar:3.1.2]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:312) ~[spring-boot-3.1.2.jar:3.1.2]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1306) ~[spring-boot-3.1.2.jar:3.1.2]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1295) ~[spring-boot-3.1.2.jar:3.1.2]
    at yt.pzn.servlet.BelajarServletApp.main(BelajarServletApp.java:12) ~[classes/:na]
Caused by: java.lang.NoClassDefFoundError: jakarta/servlet/annotation/WebServlet
    at org.springframework.boot.web.servlet.WebServletHandler.<init>(WebServletHandler.java:39) ~[spring-boot-3.1.2.jar:3.1.2]
    at org.springframework.boot.web.servlet.ServletComponentRegisteringPostProcessor.<clinit>(ServletComponentRegisteringPostProcessor.java:49) ~[spring-boot-3.1.2.jar:3.1.2]
    at org.springframework.boot.web.servlet.ServletComponentScanRegistrar$ServletComponentRegisteringPostProcessorBeanDefinition.lambda$getInstanceSupplier$0(ServletComponentScanRegistrar.java:96) ~[spring-boot-3.1.2.jar:3.1.2]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.obtainInstanceFromSupplier(AbstractAutowireCapableBeanFactory.java:1254) ~[spring-beans-6.0.11.jar:6.0.11]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.obtainInstanceFromSupplier(DefaultListableBeanFactory.java:949) ~[spring-beans-6.0.11.jar:6.0.11]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.obtainFromSupplier(AbstractAutowireCapableBeanFactory.java:1214) ~[spring-beans-6.0.11.jar:6.0.11]
    ... 16 common frames omitted
Caused by: java.lang.ClassNotFoundException: jakarta.servlet.annotation.WebServlet
    at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641) ~[na:na]
    at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188) ~[na:na]
    at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:520) ~[na:na]
    ... 22 common frames omitted


Process finished with exit code 1

pom.xml below if you need it.

<?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>3.1.2</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>yt.pzn</groupId>
    <artifactId>belajar-java-web-servlet</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>war</packaging>
    <name>Belajar Java Web Servlet</name>
    <description>Belajar Java Web Servlet</description>
    <properties>
        <java.version>17</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

</project>

请帮助我，谢谢。

Answer 1

在构建Java企业版的Web应用程序时，Servlet API和相关的Java EE API必须在运行时由Web容器（Tomcat）提供。 对于成熟的 Tomcat servlet，这些依赖项将在运行时提供，但使用嵌入式 Tomcat 时不会发生这种情况。

有两种解决方案。

解决方案1：（不推荐）

将 Tomcat 的范围从提供的更改为已编译的（注释或删除提供的）以将类包含在类路径中。

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

解决方案2： 配置您的 IDE 以将提供的依赖项添加到类路径中。

：

运行 -> 编辑配置.. -> 构建并运行 -> 修改选项 ->
将具有提供范围的依赖项添加到类路径

Answer 2

谢谢 Iman Hosseinzadeh 的回答，非常有帮助