[java] Java Spring Boot: How to map my app root (“/”) to index.html?

I'm new to Java and to Spring. How can I map my app root http://localhost:8080/ to a static index.html? If I navigate to http://localhost:8080/index.html its works fine.

My app structure is :

My config\WebConfig.java looks like this:

@Configuration
@EnableWebMvc
@ComponentScan
public class WebConfig extends WebMvcConfigurerAdapter {

    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/**").addResourceLocations("/");
        }
}

I tried to add registry.addResourceHandler("/").addResourceLocations("/index.html"); but it fails.

Update: Jan-2019

First create public folder under resources and create index.html file. Use WebMvcConfigurer instead of WebMvcConfigurerAdapter.

import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.ViewControllerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

@Configuration
public class WebAppConfig implements WebMvcConfigurer {

    @Override
    public void addViewControllers(ViewControllerRegistry registry) {
        registry.addViewController("/").setViewName("forward:/index.html");
    }

}

If you use the latest spring-boot 2.1.6.RELEASE with a simple @RestController annotation then you do not need to do anything, just add your index.html file under the resources/static folder:

project
  +-- src
      +-- main
          +-- resources
              +-- static
                  +-- index.html

Then hit the URL http://localhost:8080. Hope that it will help everyone.

1. index.html file should come under below location - src/resources/public/index.html OR src/resources/static/index.html if both location defined then which first occur index.html will call from that directory.

2. The source code looks like -

   package com.bluestone.pms.app.boot; 
   import org.springframework.boot.Banner;
   import org.springframework.boot.Banner;
   import org.springframework.boot.SpringApplication;
   import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
   import org.springframework.boot.autoconfigure.SpringBootApplication;
   import org.springframework.boot.builder.SpringApplicationBuilder;
   import org.springframework.boot.web.support.SpringBootServletInitializer;
   import org.springframework.context.annotation.ComponentScan;
   
   
   
   @SpringBootApplication 
   @EnableAutoConfiguration
   @ComponentScan(basePackages = {"com.your.pkg"}) 
   public class BootApplication extends SpringBootServletInitializer {
   
   
   
   /**
    * @param args Arguments
   */
   public static void main(String[] args) {
   SpringApplication application = new SpringApplication(BootApplication.class);
   /* Setting Boot banner off default value is true */
   application.setBannerMode(Banner.Mode.OFF);
   application.run(args);
   }
   
   /**
     * @param builder a builder for the application context
     * @return the application builder
     * @see SpringApplicationBuilder
    */
    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder 
     builder) {
       return super.configure(builder);
      }
   }
   

You can add a RedirectViewController like:

@Configuration
public class WebConfiguration implements WebMvcConfigurer {

    @Override
    public void addViewControllers(ViewControllerRegistry registry) {
        registry.addRedirectViewController("/", "/index.html");
    }
}

if it is a Spring boot App.

Spring Boot automatically detects index.html in public/static/webapp folder. If you have written any controller @Requestmapping("/") it will override the default feature and it will not show the index.html unless you type localhost:8080/index.html

An example of Dave Syer's answer:

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.ViewControllerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;

@Configuration
public class MyWebMvcConfig {

    @Bean
    public WebMvcConfigurerAdapter forwardToIndex() {
        return new WebMvcConfigurerAdapter() {
            @Override
            public void addViewControllers(ViewControllerRegistry registry) {
                // forward requests to /admin and /user to their index.html
                registry.addViewController("/admin").setViewName(
                        "forward:/admin/index.html");
                registry.addViewController("/user").setViewName(
                        "forward:/user/index.html");
            }
        };
    }

}

I had the same problem. Spring boot knows where static html files are located.

1. Add index.html into resources/static folder
2. Then delete full controller method for root path like @RequestMapping("/") etc
3. Run app and check http://localhost:8080 (Should work)

@Configuration  
@EnableWebMvc  
public class WebAppConfig extends WebMvcConfigurerAdapter {  

    @Override
    public void addViewControllers(ViewControllerRegistry registry) {
        registry.addRedirectViewController("/", "index.html");
    }

}

Inside Spring Boot, I always put the webpages inside a folder like public or webapps or views and place it inside src/main/resources directory as you can see in application.properties also.

and this is my application.properties:

server.port=15800
spring.mvc.view.prefix=/public/
spring.mvc.view.suffix=.html
spring.datasource.url=jdbc:mysql://localhost:3306/hibernatedb
spring.datasource.username=root
spring.datasource.password=password
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.MySQL5InnoDBDialect
spring.jpa.hibernate.ddl-auto = update
spring.jpa.properties.hibernate.format_sql = true

logging.level.org.hibernate.SQL=DEBUG
logging.level.org.hibernate.type.descriptor.sql.BasicBinder=TRACE

as soon you put the url like servername:15800 and this request received by Spring Boot occupied Servlet dispatcher it will exactly search the index.html and this name will in case sensitive as the spring.mvc.view.suffix which would be html, jsp, htm etc.

Hope it would help manyone.