Spring Boot with REST – Example

You just want to see an minimal example of Spring boot with REST.

This page is for you.

This example is a part of  Spring Boot with all examples

Full Code with Spring Boot 1.5.8.RELEASE:

1_spring-boot-basic.jsp

What you need for run this:

  • Maven 3
  • Java 8

What the code will do:

  • Call an url  then the service will return only data without html

Explain:

This is the file structure:

In pom.xml you need this:

<?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">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.8.RELEASE</version>
    </parent>

    <groupId>com.surasint.example</groupId>
    <artifactId>spring-boot-01</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>
    <properties>
        <maven.compiler.target>1.8</maven.compiler.target>
        <maven.compiler.source>1.8</maven.compiler.source>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

The lines that are highlighted are for Spring Boot.

Then you create a SpringBootApplication class, for example MyApplication.

package com.surasint.example;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.support.SpringBootServletInitializer;

@SpringBootApplication
public class MyApplication extends SpringBootServletInitializer {

    public static void main(String[] args) throws Exception {
        SpringApplication.run(MyApplication.class, args);
    }

}

@SpringBootApplication is to define that this class is a SpringBootApplication class.

Next, create an endpoint when you access http://localhost:8080/api/count

package com.surasint.example.web.api;

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class TestRestController {

    private static int i;

    @GetMapping("/api/count")
    public Integer count() {
        return i++;
    }
}

Try:

run this in console:

mvn clean package

Then run this to start:

mvn clean spring-boot:run

You should see something like this:

 .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v1.5.8.RELEASE)

.....
.....
2017-12-12 22:03:04.243  INFO 260 --- [           main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.context.embedded.Annotation
ConfigEmbeddedWebApplicationContext@7595f8d7: startup date [Tue Dec 12 22:03:01 CET 2017]; root of context hierarchy

Open a browswer and try to go to this url:

http://localhost:8080/api/count

You should see this: