feat: add custom exception. (#9)

Custom exception 설정을 하기 위한, ErrorCode enum, CustomException, CustomExceptionHandler, ErrorDTO를 생성. CustomException 핸들링을 동작시키기 위한 Security 설정을 추가함.
CustomException 핸들링 동작을 확인할 수 있는 test api 추가 (api/develop/v1/unauthorized, api/develop/v1/bad-request)

src/main/java/com/compono/ibackend/common/dto/ErrorDTO.java

@@ -0,0 +1,30 @@
+package com.compono.ibackend.common.dto;
+
+import com.compono.ibackend.common.enumType.ErrorCode;
+import com.compono.ibackend.common.exception.CustomException;
+import lombok.Builder;
+import lombok.Data;
+import org.springframework.http.ResponseEntity;
+
+@Data
+@Builder
+public class ErrorDTO {
+
+    private Integer code;
+    private String msg;
+    private String detail;
+
+    public static ResponseEntity<ErrorDTO> toResponseEntity(CustomException ex) {
+        ErrorCode errorType = ex.getErrorCode();
+        String detail = ex.getDetail();
+
+        return ResponseEntity
+                .status(ex.getStatus())
+                .body(ErrorDTO.builder()
+                        .code(errorType.getCode())
+                        .msg(errorType.getMsg())
+                        .detail(detail)
+                        .build());
+    }
+}
+

src/main/java/com/compono/ibackend/common/enumType/ErrorCode.java

@@ -0,0 +1,18 @@
+package com.compono.ibackend.common.enumType;
+
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+@Getter
+@RequiredArgsConstructor
+public enum ErrorCode {
+    // 400
+    UNKNOWN(4000, "알 수 없는 에러가 발생했습니다."),
+    INVALID_PASSWORD(4001, "유효하지 않은 비밀번호 입니다."),
+
+    // 401
+    EXPIRED_TOKEN(4010, "만료된 토큰입니다.");
+
+    private final int code;
+    private final String msg;
+}

src/main/java/com/compono/ibackend/common/exception/CustomException.java

@@ -0,0 +1,55 @@
+package com.compono.ibackend.common.exception;
+
+import com.compono.ibackend.common.enumType.ErrorCode;
+import lombok.Getter;
+import org.springframework.http.HttpStatus;
+
+@Getter
+public class CustomException extends RuntimeException {
+    private final HttpStatus status;
+    private final ErrorCode errorCode;
+    private final String detail;
+
+    public CustomException(HttpStatus status, ErrorCode errorCode) {
+        this.status = status;
+        this.errorCode = errorCode;
+        this.detail = "";
+    }
+
+    public CustomException(HttpStatus status, ErrorCode errorCode, String detail) {
+        this.status = status;
+        this.errorCode = errorCode;
+        this.detail = detail;
+    }
+
+    public CustomException(HttpStatus status, ErrorCode errorCode, Throwable cause) {
+        this.status = status;
+        this.errorCode = errorCode;
+        this.detail = cause.getMessage();
+    }
+
+    public CustomException(HttpStatus status, CustomException customException) {
+        this.status = status;
+        this.errorCode = customException.getErrorCode();
+        this.detail = customException.getDetail();
+    }
+
+    public CustomException(HttpStatus status, Throwable cause) {
+        this.status = status;
+        this.errorCode = ErrorCode.UNKNOWN;
+        this.detail = cause.getMessage();
+    }
+
+    public CustomException(Exception exception) {
+        if (exception.getClass() == CustomException.class) {
+            CustomException customException = (CustomException) exception;
+            this.status = customException.getStatus();
+            this.errorCode = customException.getErrorCode();
+            this.detail = customException.getMessage();
+        } else {
+            this.status = HttpStatus.BAD_REQUEST;
+            this.errorCode = ErrorCode.UNKNOWN;
+            this.detail = exception.getMessage();
+        }
+    }
+}

src/main/java/com/compono/ibackend/common/handler/CustomExceptionHandler.java

@@ -0,0 +1,16 @@
+package com.compono.ibackend.common.handler;
+
+import com.compono.ibackend.common.dto.ErrorDTO;
+import com.compono.ibackend.common.exception.CustomException;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.ControllerAdvice;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+
+@ControllerAdvice
+public class CustomExceptionHandler {
+
+    @ExceptionHandler(CustomException.class)
+    protected ResponseEntity<ErrorDTO> handleCustom400Exception(CustomException ex) {
+        return ErrorDTO.toResponseEntity(ex);
+    }
+}

src/main/java/com/compono/ibackend/config/SecurityConfig.java

@@ -0,0 +1,34 @@
+package com.compono.ibackend.config;
+
+import jakarta.servlet.DispatcherType;
+import lombok.RequiredArgsConstructor;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.security.config.annotation.web.builders.HttpSecurity;
+import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
+import org.springframework.security.web.SecurityFilterChain;
+
+@RequiredArgsConstructor
+@EnableWebSecurity
+@Configuration
+public class SecurityConfig {
+
+    private static final String[] DEFAULT_WHITELIST = {
+            "/status", "/images/**", "/error/**"
+    };
+
+    private static final String[] DEVELOP_TEST_PATH = {
+            "api/develop/**",
+    };
+
+    @Bean
+    protected SecurityFilterChain config(HttpSecurity http) throws Exception {
+        http.authorizeHttpRequests(request -> request
+                .dispatcherTypeMatchers(DispatcherType.FORWARD).permitAll()
+                .requestMatchers(DEFAULT_WHITELIST).permitAll()
+                .requestMatchers(DEVELOP_TEST_PATH).permitAll()
+                .anyRequest().authenticated()
+        );
+        return http.build();
+    }
+}

src/main/java/com/compono/ibackend/develop/controller/DevelopController.java

@@ -0,0 +1,34 @@
+package com.compono.ibackend.develop.controller;
+
+import com.compono.ibackend.common.enumType.ErrorCode;
+import com.compono.ibackend.common.exception.CustomException;
+import lombok.RequiredArgsConstructor;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+@RequiredArgsConstructor
+@RequestMapping("api/develop/")
+public class DevelopController {
+
+    @GetMapping("v1/bad-request")
+    public ResponseEntity<Object> test400Error() {
+        try {
+            throw new CustomException(HttpStatus.BAD_REQUEST, ErrorCode.INVALID_PASSWORD);
+        } catch (Exception ex) {
+            throw new CustomException(ex);
+        }
+    }
+
+    @GetMapping("v1/unauthorized")
+    public ResponseEntity<Object> test401Error() {
+        try {
+            throw new CustomException(HttpStatus.UNAUTHORIZED, ErrorCode.EXPIRED_TOKEN);
+        } catch (Exception ex) {
+            throw new CustomException(ex);
+        }
+    }
+}