我在做一个小项目。它使用MongoDB作为数据库。我想在我的Player Bean上添加验证。但只要我添加以下依赖项：

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

在我的pom.xml文件中。

当我作为Spring Boot应用程序运行时，我的项目开始失败。

下面是我的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 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>2.7.3</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.classhacker</groupId>
    <artifactId>tttapi</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>tttapi</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-mongodb</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-validation</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

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

</project>

下面是我的Player Bean：

package com.classhacker.tttapi.domain;

import org.springframework.data.annotation.Id;
import org.springframework.data.mongodb.core.mapping.Document;

@Document
public class Player {

    @Id
    int _id;

    String name;

    int gamesWon;

    public Player(int _id, String name, int gamesWon) {
        super();
        this._id = _id;
        this.name = name;
        this.gamesWon = gamesWon;
        }

    public int get_id() {
        return _id;
    }

    public String getName() {
        return name;
    }

    public int getGamesWon() {
        return gamesWon;
    }

    @Override
    public String toString() {
        return String.format("Player[id=%d, name=%s, gamesWon=%d]", _id, name, gamesWon);
    }
}

添加验证依赖项后，我收到的错误如下：

Error: Could not find or load main class com.classhacker.tttapi.DemoApplication
Caused by: java.lang.ClassNotFoundException: com.classhacker.tttapi.DemoApplication

但是，如果我删除了Spring Boot验证依赖项，我的项目不会给出任何错误。

如果有人能给我解释一下这里出了什么问题，那将是非常有帮助的。