week_05 SpringBoot 1/?

HomeController.java

package com.ll.sb1114prac;

import lombok.AllArgsConstructor;
import lombok.Getter;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;

@Controller
public class HomeController {

    @GetMapping("/") // @GetMapping -> 액션 메서드
    @ResponseBody // return 값을 그대로 브라우저에 전송
    String showMain() {
        return "안녕하세요";
    }

    @GetMapping("/about")
    @ResponseBody
    String showAbout() {
        return "개발자 커뮤니티";
    }

    @GetMapping("/calc")
    @ResponseBody
    String showCalc(Integer a, Integer b) {
        return "계산 결과 : %d".formatted(a + b);
    }

    @GetMapping("/calc2")
    @ResponseBody
    String showCalc2(Integer a, Integer b) {
        return "a:"+a+" b:"+b;
    }

    @GetMapping("/calc3")
    @ResponseBody
    String showCalc3(
            @RequestParam(defaultValue = "0") int a,
            @RequestParam(defaultValue = "0") int b
    ) {
        return "계산 결과 : %d".formatted(a + b);
    }

    @GetMapping("/calc4")
    @ResponseBody
    String showCalc4(
            @RequestParam(defaultValue = "0") double a,
            @RequestParam(defaultValue = "0") double b
    ) {
        return "계산 결과 : %f".formatted(a + b);
    }

    @GetMapping("/calc5")
    @ResponseBody
    String showCalc5(
            @RequestParam(defaultValue = "0") String a,
            @RequestParam(defaultValue = "0") String b
    ) {
        return "계산 결과 : %s".formatted(a + b);
    }

    @GetMapping("/calc6")
    @ResponseBody
    int showCalc6(
            int a, int b
    ) {
        return a + b;
    }

    @GetMapping("/calc7")
    @ResponseBody
    boolean showCalc7(
            int a, int b
    ) {
        return a > b;
    }

    @GetMapping("/calc8")
    @ResponseBody
    Person showCalc8(
            String name, int age
    ) {
        return new Person(name, age);
    }

    @GetMapping("/calc9")
    @ResponseBody
    Person2 showCalc9(
            String name, int age
    ) {
        return new Person2(name+"2", age);
    }

    @GetMapping("/calc10")
    @ResponseBody
    Map<String, Object> showCalc10(
            String name, int age
    ) {
        Map<String, Object> personMap = Map.of(
                "name", name,
                "age", age  // 뭐지??
                // Map.of은 불변(immutable)한 Map을 생성하는 메서드
                // 거기서 key-value 쌍을 만드는 방법임
        );
        return personMap;
    }

    @GetMapping("/calc11")
    @ResponseBody
    List<Integer> showCalc11() {
        List<Integer> nums = new ArrayList<>() {{
            add(10);
            add(-2344);
            add(3403);
        }}; // 왜 중괄호 2개?? -> 더블 블레이스 초기화 (익명 클래스 + 생성자)
        // ArrayList 초기화: 외부 중괄호 {}는 ArrayList 상속받은 익명 클래스 생성.
        // => 익명 클래스에서 인스턴스를 생성 동시에 객체 초기화 수행 가능
        //초기화 블록: 내부 중괄호 {}는 익명 클래스의 초기화 블록.
        // => 익명 클래스의 인스턴스 생성과 동시에 추가적인 작업 수행 가능
        return nums;
    }

    @GetMapping("/calc12")
    @ResponseBody
    int[] showCalc12() {
        int[] nums = new int[]{10, -23423, 234};
        return nums;
    }

    @GetMapping("/calc13")
    @ResponseBody
    List<Person2> showCalc13(
            String name, int age
    ) {
        List<Person2> persons = new ArrayList<>() {{
            add(new Person2(name, age));
            add(new Person2(name+"!", age+1));
            add(new Person2(name+"A", age+2));
        }};
        return persons;
    }

    @GetMapping("/calc14")
    @ResponseBody
    String showCalc14() {
        String html = "";
        html += "<div>";
        html += "<input type=\"text\" placeholder=\"내용\">";
        html += "</div>";

        return html;
    }

    @GetMapping("/calc15")
    @ResponseBody
    StringBuilder showCalc15() {
        StringBuilder html = new StringBuilder(); // 문자열 불변성을 위해
        html.append("<div>");
        html.append("<input type=\"text\" placeholder=\"내용\">");
        html.append("</div>");

        return html;
    }

    @GetMapping("/calc16")
    @ResponseBody
    String showCalc16() {
        String html = "<div><input type=\"text\" placeholder=\"내용\"></div>";
        return html;
    }

    @GetMapping("/calc17")
    @ResponseBody
    String showCalc17() {
        String html = """
                <div>
                    <input type="text" placeholder="내용">
                </div>
                """;
        return html;
    }

    @GetMapping("/calc18")
    @ResponseBody
    String showCalc18() {
        String html = """
                <div>
                    <input type="text" placeholder="내용" value="반가워요">
                </div>
                """;
        return html;
    }

    @GetMapping("/calc19")
    @ResponseBody
    String showCalc19(
            @RequestParam(defaultValue = "") String subject,
            @RequestParam(defaultValue = "") String content
    ) {
        String html = """
                <div>
                    <input type="text" placeholder="주제" value="%s">
                </div>
                <div>
                    <input type="text" placeholder="내용" value="%s">
                </div>
                """.formatted(subject, content);
        return html;
    }

    @GetMapping("/calc20")
    String showCalc20() {
        return "calc20";
    }

    @GetMapping("/calc21")
    String showCalc21(Model model) {
        model.addAttribute("v1", "안녕");
        model.addAttribute("v2", "반가워");
        return "calc21";
    }

    int num = 0; // HomeController 인스턴스 변수
    @GetMapping("/calc22")
    @ResponseBody
    int showCalc22() {
        num++;
        return num;
    }

}

@AllArgsConstructor
class Person {
    public String name;
    public int age;
}

@AllArgsConstructor
class Person2 {
    @Getter
    private String name;
    @Getter
    private int age;
}

ArticleController.java

▼ String으로 doWrite 메서드 만들기

package com.ll.sb1114prac;

import lombok.AllArgsConstructor;
import lombok.Getter;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import java.util.HashMap;
import java.util.Map;

@Controller
public class ArticleController {
    @GetMapping("/article/write") // @GetMapping -> 액션 메서드
    String showWrite() {
        return "article/write.html";
    }


    @GetMapping("/article/dowrite")
    @ResponseBody
    String doWrite(
            String title,
            String body
    ) {
        return "게시물이 작성되었습니다.";
    }

}

▼ Article 객체 사용 doWrite 메서드 만들기

package com.ll.sb1114prac;

import lombok.AllArgsConstructor;
import lombok.Getter;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import java.util.HashMap;
import java.util.Map;

@Controller
public class ArticleController {
    @GetMapping("/article/write")
    String showWrite() {
        return "article/write.html";
    }

    @GetMapping("/article/dowrite")
    @ResponseBody
    Article doWrite(
            String title,
            String body
    ) {
        Article article = new Article(1, title, body);
        return article;
    }

}

@AllArgsConstructor
@Getter
class Article {
    private long id;
    private String title;
    private String body;
}

▼ Map 객체 사용 doWrite 메서드 만들기

package com.ll.sb1114prac;

import lombok.AllArgsConstructor;
import lombok.Getter;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import java.util.HashMap;
import java.util.Map;

@Controller
public class ArticleController {

    private Article lastArticle;

    @GetMapping("/article/write")
    String showWrite() {
        return "article/write.html";
    }

    @GetMapping("/article/doWrite")
    @ResponseBody
    Map<String, Object> doWrite(
            String title,
            String body
    ) {
        lastArticle = new Article(1, title, body);

        Map<String, Object> rs = new HashMap<>();
        rs.put("msg", "1번 게시물이 작성되었습니다.");
        rs.put("data", lastArticle);

        return rs;
    }

    @GetMapping("/article/getLastArticle")
    @ResponseBody
    Article getLastArticle() {
        return lastArticle;
    }

}

@AllArgsConstructor
@Getter
class Article {
    private long id;
    private String title;
    private String body;
}