Spring boot controller issue, getting whitelabel page error ,what might be wrong here? - spring

Question

I have made projects before on spring and never got any issue like this before ,i just can't seem to figure out what is wrong here, all dependencies are correctly imported .
Here is how my vaultengine.java looks like :
VaultEngine.java :
package com.example.VaultEngine;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
#SpringBootApplication
#Controller
public class VaultEngineApplication {
public static void main(String[] args) {
SpringApplication.run(VaultEngineApplication.class, args);
}
#GetMapping("/h")
public String greetingForm() {
return "index.html";
}
}
I am using a custom port cause i have 8080 in use somewhere already.
application.properties:
server.port=8989
All dependencies are properly loaded.
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>2.2.6.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>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-test</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
<version>2.2.6.RELEASE</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.19</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
<plugin>
<groupId>com.google.cloud.tools</groupId>
<artifactId>appengine-maven-plugin</artifactId>
<version>1.3.2</version>
<configuration>
<version>1</version>
</configuration>
</plugin>
</plugins>
</build>
</project>

Answer 1

You are using spring-boot-starter-thymeleaf, so
#GetMapping("/h")
public String greetingForm() {
return "index";
}
and put index.html to src/main/resources/templates/.
refs:
https://spring.io/guides/gs/serving-web-content/
https://docs.spring.io/spring-boot/docs/2.2.6.RELEASE/reference/htmlsingle/#boot-features-spring-mvc-template-engines
https://docs.spring.io/spring/docs/5.2.7.RELEASE/spring-framework-reference/web.html#mvc-controller

Answer 2

Use #RestController instead of #Controller
#SpringBootApplication
#RestController
public class DemoApplication {
public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
#GetMapping("/h")
public String greetingForm() {
return "index.html";
}
}