为什么springboot的内嵌容器的war项目不支持jsp？

Question

我用springboot创建了一个war项目并添加了webapp和WEB-INF和web.xml但是请求并不能跳转到jsp页面（404报错），为什么啊？



pom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>2.2.5.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.test</groupId>
    <artifactId>spring-web-demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>war</packaging>
    <name>spring-web-demo</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-web</artifactId>
        </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>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>

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

</project>

启动类

Answer 1

贴一下你的pom和启动类

---

更新
@weisir
springboot默认以jar包和main方式启动(在web包下含tomcat内嵌容器)；另外一种是war包启动(需要手动排除内嵌容器)并且将main方法启动改成servlet方式启动，这一点和以前的spring启动没区别，都需要web.xml文件等，但servlet3.0后可以用实现类方式启动，springboot将需要实现的类包装了下，即SpringBootServletInitializer实现configure方法即可。
你的项目是自动生成的没错，但默认内嵌服务器不支持JSP模板(别的模板可以)最起码不友好，你只把maven的打包方式改成了war是不够的，解决方案代码层面如下另外需要在IDE里配置web服务器：

@SpringBootApplication
@RestController
public class SpringbootDemoApplication extends SpringBootServletInitializer {

    @RequestMapping("/hello")
    public String hello() {
        return "hello world";
    }

 
    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {
        return builder.sources(SpringbootDemoApplication.class);
    }

}

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