Internal resource view resolver not working in spring boot

I have created my "fancy-login.jsp" in src/main/webapp/WEB-INF/view/fancy-login.jsp but my jsp page is not shown when I access localhost:8080/book/login its shown just the page name fancy-login means the string is printed as it is rather than my jsp page.
Please help me resolve it.

> Bean

 @Bean
	public ViewResolver viewResolver() {
		
		InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();
		
		viewResolver.setPrefix("/WEB-INF/view/");
		viewResolver.setSuffix(".jsp");
		
		return viewResolver;
	}

> Controller file

@RestController
@RequestMapping("/book")
public class BookController {

	@GetMapping("/login")
	public String getLoggedIn() {
		
		return "fancy-login";
	}
}

> pom.xml file

    <?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>2.3.1.RELEASE</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>
	<groupId>com.demo</groupId>
	<artifactId>book</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<name>book</name>
	<description>Demo project for Spring Boot</description>
	<packaging>war</packaging>
	
	<properties>
		<java.version>1.8</java.version>
	</properties>

	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-security</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-jdbc</artifactId>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-devtools</artifactId>
			<scope>runtime</scope>
			<optional>true</optional>
		</dependency>
		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
			<scope>runtime</scope>
		</dependency>
		<dependency>
			<groupId>com.mchange</groupId>
			<artifactId>c3p0</artifactId>
			<version>0.9.5.5</version>
		</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>
		<dependency>
			<groupId>org.springframework.security</groupId>
			<artifactId>spring-security-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>

> folder structure

https://i.stack.imgur.com/D0Wv0.png

Replace @RestController with @Controller as a rest controller will not resolve a view , it will only return the data.

@Controller
@RequestMapping("/book")
public class BookController {

    @GetMapping("/login")
    public String getLoggedIn() {
        
        return "fancy-login";
    }
}

Since you are using jsp with springboot make sure that you are using a war packaging instead of the default jar . Jsp does not work well with the jar as packaging.

You could also configure the jsp view resolver by just providing the values in application.properties like :

#ViwResolver
spring.mvc.view.prefix=/WEB-INF/view/
spring.mvc.view.suffix=.jsp

In your case if you are using maven then find pom.xml in your ide and then add the following under version tag :

<packaging>war</packaging>

Also if you are using embedded tomcat add the following under dependency secton of your pom :

  <dependency>
     <groupId>org.apache.tomcat.embed</groupId>
     <artifactId>tomcat-embed-jasper</artifactId>
     <scope>provided</scope>
  </dependency>

And also add JSP Servlet and JSTL support if used in your JSP page then only