$$config title: [스프링 수업 코드] keywords: - spring - springboot $$ # 코드 ```java package com.mysite.sbb; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.*; @Controller public class MainController { int increaseNum = 0; @RequestMapping("/sbb") @ResponseBody public String index() { System.out.println("sbb"); return "sbb"; } @GetMapping("/page1") @ResponseBody public String showPage1() { return """ """; } @PostMapping("/page2") @ResponseBody public String showPage2Post(@RequestParam(value = "age", defaultValue = "0") int age) { System.out.println("age : " + age); return """

입력된 나이 : %d

POST 방식으로 옴

""".formatted(age); } @GetMapping("/plus") @ResponseBody public int plus(int a, int b) { return a + b; } // localhost:8081/plus?a=3&b=1 입력시 4 출력됨 @GetMapping("/minor") @ResponseBody public int minus (int a, int b) { return a - b; } @GetMapping("/increase") @ResponseBody public int increases () { return increaseNum++; } } ``` # setSession에서 입력한 값 getSession 에서 불러오기 ## 코드 ```java ackage com.mysite.sbb; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.bind.annotation.ResponseBody; import javax.servlet.http.HttpSession; @Controller public class MainController { @GetMapping("/saveSessionAge") @ResponseBody public String saveSessionAge(@RequestParam("age") int age, HttpSession session) { //HttpSession 객체 사용하여 System.out.println("age : " + age); session.setAttribute("age", age); return "나이 %d이 세션에 저장되었습니다.".formatted(age); } @GetMapping("/getSessionAge") @ResponseBody public String saveSession(HttpSession session) { //이곳에서 불러옴 int age = (int) session.getAttribute("age"); return "세션에 저장된 나이는 %d살입니다.".formatted(age); } } ``` # Getter 사용 ```java package com.mysite.sbb; import lombok.AllArgsConstructor; import lombok.Getter; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.bind.annotation.ResponseBody; import javax.servlet.http.HttpSession; @Controller public class MainController { @GetMapping("/addPerson") @ResponseBody public Person addPerson(int id, int age, String name) { Person p = new Person(id, age, name); return p; } } @Getter @AllArgsConstructor class Person { private int id; private int age; private String name; // public Person(int id, int age, String name) { // this.id = id; // this.age = age; // this.name = name; // } AllArgsConstructor 사용하면 생성자 따로 작성안해도됨 } ``` # 매개변수 사용하지않고 출력하기 ```java package com.mysite.sbb; import lombok.AllArgsConstructor; import lombok.Getter; import lombok.Setter; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.bind.annotation.ResponseBody; import javax.servlet.http.HttpSession; @Controller public class MainController { @GetMapping("/addPerson") @ResponseBody public Person addPerson(Person person) { return person; } } @Getter @AllArgsConstructor class Person { private int id; private int age; private String name; } ``` # URL + 변수 출력 ## <1> @PathVariable [참고사이트](https://byul91oh.tistory.com/435) ```java package com.mysite.sbb; import lombok.AllArgsConstructor; import lombok.Getter; import lombok.Setter; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.bind.annotation.ResponseBody; import javax.servlet.http.HttpSession; @Controller public class MainController { @GetMapping("/addPerson/{id}") ==> 변수출력 @ResponseBody public Person addPerson(Person person, @PathVariable("id") int id) { ==> @pathvariable 작성 return person; } } @Getter @AllArgsConstructor class Person { private int id; private int age; private String name; } ``` ![이미지](https://ifh.cc/g/alZtWP.png) ## <2> @PathVariable 사용하지않아도 id값 출력됨 => 스프링의 기능중 하나 ! ```java package com.mysite.sbb; import lombok.AllArgsConstructor; import lombok.Getter; import lombok.Setter; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.bind.annotation.ResponseBody; import javax.servlet.http.HttpSession; @Controller public class MainController { @GetMapping("/addPerson/{id}") ==> 변수출력 @ResponseBody public Person addPerson(Person person) { ==> @pathvariable 작성안함 return person; } } @Getter @AllArgsConstructor class Person { private int id; private int age; private String name; } ``` ## <3> @PathVariable 여러개도 사용 가능 ```java package com.mysite.sbb; import lombok.AllArgsConstructor; import lombok.Getter; import lombok.Setter; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.bind.annotation.ResponseBody; import javax.servlet.http.HttpSession; @Controller public class MainController { @GetMapping("/addPerson/{id}/{age}") ==> 변수출력 @ResponseBody public Person addPerson(Person person, @PathVariable("id") int id, @PathVariable("age") int age) { ==> @pathvariable 작성 return person; } } @Getter @AllArgsConstructor class Person { private int id; private int age; private String name; } ``` ![이미지](https://ifh.cc/g/hzLDAH.png) # 구구단 출력 ```java @GetMapping("/gugudan") @ResponseBody public String gugudan(int dan, int limit) { String result = ""; for (int i = 1; i <= limit; i++) { result += dan + " * " + i + " = " + (dan * i) + "
"; } return result; } ```