Spring REST API 기본호출 구현

• HelloWorldController 를 만들어 기본적인 REST API 연결 확인
  • 함수명 : helloWorld
  • 리턴값 : String
  • Parameter 값 : 없음
  • Method 상단에 @GetMapping(path ="/hello-world") 추가
  • 호출 URL : http://localhost:8088/hello-world
  • Reponse : HttpStatus = 200 / Value = Hello World

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

    @RestController
    public class HelloWorldController {
    		//GET
        // /hello-world (endpoint)
        //@RequestMapping(mehtod=RequestMethod.Get, path="/hello-world")
        @GetMapping(path ="/hello-world")
        public String helloWorld(){
            return "Hello World";
        }
    }

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• HelloWorldController 에 Bean을 추가하여 REST API 호출
  • 함수명 : helloWorldBean
  • 리턴값 : HelloWorldBean
  • Parameter 값 : 없음
  • Method 상단에 @GetMapping(path ="/hello-world-bean") 추가
  • 호출 URL : http://localhost:8088/hello-world-bean

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

    @RestController
    public class HelloWorldController {
    		//GET
        // /hello-world (endpoint)
        //@RequestMapping(mehtod=RequestMethod.Get, path="/hello-world")
        @GetMapping(path ="/hello-world")
        public String helloWorld(){
            return "Hello World";
        }

    		@GetMapping(path ="/hello-world-bean")
        public HelloWorldBean helloWorldBean(){
            return new HelloWorldBean("Hello World");
        }
    }

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• HelloWorldBean 추가
  • 변수타입 / 변수명 : String / message
  • Lombok Annotation으로 setter / getter / toString 생성 → @Data
  • Lombok Annotation으로 Contructor생성 → @AllArgsContructor

    package com.example.restfulwebservice.helloworld;

    import lombok.AllArgsConstructor;
    import lombok.Data;

    @Data 
    @AllArgsConstructor
    public class HelloWorldBean {
        private String message;
    }

• http://localhost:8088/hello-world-bean 호출 - JSON 결과값 확인

    {
        "message": "Hello World"
    }

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• PathVariable 사용
  • HelloWorldController에 helloWorldBean 메서드 추가
  • 함수명 : helloWorldBean
  • 리턴값 : HelloWorldBean
  • Parameter 값 : String name
  • Method 상단에 @GetMapping(path ="/hello-world-bean/path-variable/{name}") 추가
  • Parameter에 @PathVariable(value="name") 추가
  • 호출 URL : http://localhost:8088/hello-world-bean/path-variable/abcdef

    import org.springframework.web.bind.annotation.PathVariable;

    @GetMapping(path ="/hello-world-bean/path-variable/{name}")
    public HelloWorldBean helloWorldBean(@PathVariable(value="name") String name){
    	return new HelloWorldBean(String.format("Hello World, %s",name));
    }

• http://localhost:8088/hello-world-bean/path-variable/abcdef URL 호출

    {
        "message": "Hello World, a"
    }{
        "message": "Hello World, abcdef"
    }

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