我在这个视频里做了所有的事情：但是当我打字的时候： http://localhost:8080/spring-sample-1.0-SNAPSHOT/hello 此错误显示为：

HTTP Status 404 – Not Found
Type Status Report

Message The requested resource [/spring-sample-1.0-SNAPSHOT/hello] is not available

Description The origin server did not find a current representation for the target resource or is not willing to disclose that one exists.

我唯一更改的地方是：tomcat/bin/setclasspath.bat，我在那里添加了一行：

set JRE_HOME=C:\Program Files\Java\jre1.8.0_271

因为没有这个服务器就不能启动
好的，所以我的应用程序非常简单，我用java 15创建了mvn项目，然后创建了两个类：
配置：

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;

@Configuration
@ComponentScan({"app"})
@EnableWebMvc
public class Config extends AbstractAnnotationConfigDispatcherServletInitializer {
    @Override
    protected Class<?>[] getRootConfigClasses() {
        return new Class[0];
    }

    @Override
    protected Class<?>[] getServletConfigClasses() {
        return new Class[0];
    }

    @Override
    protected String[] getServletMappings() {
        return new String[0];
    }
}

你好：

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class Hello {

    @GetMapping("/hello")
    public String get(){
        return "Bycza zagroda!";
    }
}

pom.xml文件：

<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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>pl.bykowski</groupId>
    <artifactId>spring-sample</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>war</packaging>

    <properties>
        <maven.compiler.source>15</maven.compiler.source>
        <maven.compiler.target>15</maven.compiler.target>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.1.5.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>2.9.8</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.9.8</version>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>4.0.1</version>
            <scope>provided</scope>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-war-plugin</artifactId>
                <version>3.2.3</version>
                <configuration>
                    <failOnMissingWebXml>false</failOnMissingWebXml>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

然后我将所有内容打包到war文件中，并将其添加到tomcat管理器中：要部署的war文件
之后，我在tomcat模块中单击了/spring-sample-1.0-snapshot
最后打招呼
有什么问题吗/