Why SpringBoot example doesn't work like this? - spring

Question

So there is an example from the Spring web-site:
package com.example;
import org.springframework.boot.*;
import org.springframework.boot.autoconfigure.*;
import org.springframework.stereotype.*;
import org.springframework.web.bind.annotation.*;
#RestController
#EnableAutoConfiguration
public class Example {
#RequestMapping("/")
String home() {
return "Hello World!";
}
public static void main(String[] args) throws Exception {
SpringApplication.run(Example.class, args);
}
}
which works fine. There are notes #RestController is #Controller + #ResponseBody and The #SpringBootApplication annotation is equivalent to using #Configuration, #EnableAutoConfiguration and #ComponentScan.
My question is: Why is there 404 error accessing "/" if I use annotations below?
#ResponseBody
#SpringBootApplication
public class Example { ... }

Answer 1

Using the #ResponseBody annotation alone isn't enough to tell Spring that your class is a MVC controller. You either need to use #RestController:
#RestController
#SpringBootApplication
public class Example { ... }
or #Controller and #ResponseBody:
#Controller
#ResponseBody
#SpringBootApplication
public class Example { ... }

Answer 2

pom
<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<artifactId>quick-log</artifactId>
<groupId>com.quick</groupId>
<version>1.0-SNAPSHOT</version>
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.2.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<exclusions>
<exclusion>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-logging</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-log4j2</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-aop</artifactId>
</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>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
</plugins>
</build>
</project>
main function
#SpringBootApplication
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
}
controller
#RestController
#RequestMapping("/")
public class ApiController {
#RequestMapping("/hello")
public String hello(){
return "Hello World!";
}
}
easy to work~
you can find some quick and simple sample in github like this
https://github.com/vector4wang/spring-boot-quick