feat: 게시글 인라인 이미지 서버 업로드(DB 저장) — base64 대체

- board_image 테이블 + BoardImageController/Service/Mapper
  · POST /api/board/images(로그인) → {url:/api/images/{id}}
  · GET  /api/images/{id}(공개, img src 로 로드) — 1년 캐시
- 본문엔 짧은 URL 만 들어가 글이 비대해지지 않음

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/main/java/com/sb/web/board/controller/BoardImageController.java

@@ -0,0 +1,57 @@
+package com.sb.web.board.controller;
+
+import com.sb.web.auth.dto.SessionUser;
+import com.sb.web.auth.web.AuthInterceptor;
+import com.sb.web.board.domain.BoardImage;
+import com.sb.web.board.service.BoardImageService;
+import com.sb.web.common.exception.ApiException;
+import lombok.RequiredArgsConstructor;
+import org.springframework.http.CacheControl;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.*;
+import org.springframework.web.multipart.MultipartFile;
+
+import java.io.IOException;
+import java.util.Map;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * 게시글 인라인 이미지.
+ *   POST /api/board/images   업로드(로그인 필요) → {url: "/api/images/{id}"}
+ *   GET  /api/images/{id}     이미지 바이트(공개 — img src 로 인증 없이 로드)
+ */
+@RestController
+@RequiredArgsConstructor
+public class BoardImageController {
+
+    private final BoardImageService service;
+
+    @PostMapping("/api/board/images")
+    public Map<String, String> upload(
+            @RequestParam("image") MultipartFile file,
+            @RequestAttribute(AuthInterceptor.CURRENT_MEMBER) SessionUser current) throws IOException {
+        if (file.isEmpty()) {
+            throw new ApiException(HttpStatus.BAD_REQUEST, "이미지가 비어 있습니다.");
+        }
+        String contentType = file.getContentType();
+        if (contentType == null || !contentType.startsWith("image/")) {
+            throw new ApiException(HttpStatus.BAD_REQUEST, "이미지 파일만 업로드할 수 있습니다.");
+        }
+        Long id = service.save(current.getId(), contentType, file.getBytes());
+        return Map.of("url", "/api/images/" + id);
+    }
+
+    @GetMapping("/api/images/{id}")
+    public ResponseEntity<byte[]> get(@PathVariable Long id) {
+        BoardImage img = service.get(id);
+        if (img == null) {
+            return ResponseEntity.notFound().build();
+        }
+        return ResponseEntity.ok()
+                .contentType(MediaType.parseMediaType(img.getContentType()))
+                .cacheControl(CacheControl.maxAge(365, TimeUnit.DAYS).cachePublic())
+                .body(img.getData());
+    }
+}

src/main/java/com/sb/web/board/domain/BoardImage.java

@@ -0,0 +1,26 @@
+package com.sb.web.board.domain;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import java.time.LocalDateTime;
+
+/**
+ * 게시글 인라인 이미지. board_image 테이블과 매핑(DB 저장).
+ * 본문에는 base64 대신 /api/images/{id} URL 만 들어간다.
+ */
+@Data
+@Builder
+@NoArgsConstructor
+@AllArgsConstructor
+public class BoardImage {
+
+    private Long id;
+    private Long memberId;
+    private String contentType;
+    private byte[] data;
+    private Integer byteSize;
+    private LocalDateTime createdAt;
+}

src/main/java/com/sb/web/board/mapper/BoardImageMapper.java

@@ -0,0 +1,13 @@
+package com.sb.web.board.mapper;
+
+import com.sb.web.board.domain.BoardImage;
+import org.apache.ibatis.annotations.Mapper;
+import org.apache.ibatis.annotations.Param;
+
+@Mapper
+public interface BoardImageMapper {
+
+    int insert(BoardImage image);
+
+    BoardImage findById(@Param("id") Long id);
+}

src/main/java/com/sb/web/board/service/BoardImageService.java

@@ -0,0 +1,33 @@
+package com.sb.web.board.service;
+
+import com.sb.web.board.domain.BoardImage;
+import com.sb.web.board.mapper.BoardImageMapper;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+/**
+ * 게시글 인라인 이미지 저장/조회 (DB 저장).
+ */
+@Service
+@RequiredArgsConstructor
+public class BoardImageService {
+
+    private final BoardImageMapper mapper;
+
+    @Transactional
+    public Long save(Long memberId, String contentType, byte[] data) {
+        BoardImage img = BoardImage.builder()
+                .memberId(memberId)
+                .contentType(contentType)
+                .data(data)
+                .byteSize(data.length)
+                .build();
+        mapper.insert(img);
+        return img.getId();
+    }
+
+    public BoardImage get(Long id) {
+        return mapper.findById(id);
+    }
+}

src/main/resources/db/board.sql

@@ -70,6 +70,18 @@ CREATE TABLE IF NOT EXISTS board_setting (
 
 INSERT IGNORE INTO board_setting (id, tag_category_id) VALUES (1, NULL);
 
+-- 게시글 인라인 이미지 (DB 저장). 본문에는 /api/images/{id} URL 만 포함(base64 미사용).
+CREATE TABLE IF NOT EXISTS board_image (
+    id           BIGINT       NOT NULL AUTO_INCREMENT,
+    member_id    BIGINT       NOT NULL,
+    content_type VARCHAR(100) NOT NULL,
+    data         LONGBLOB     NOT NULL,
+    byte_size    INT          NOT NULL DEFAULT 0,
+    created_at   DATETIME     NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    PRIMARY KEY (id),
+    KEY idx_board_image_member (member_id)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
+
 -- 댓글
 CREATE TABLE IF NOT EXISTS comment (
     id          BIGINT        NOT NULL AUTO_INCREMENT,

src/main/resources/mapper/BoardImageMapper.xml

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
+        "https://mybatis.org/dtd/mybatis-3-mapper.dtd">
+<mapper namespace="com.sb.web.board.mapper.BoardImageMapper">
+
+    <insert id="insert" parameterType="com.sb.web.board.domain.BoardImage"
+            useGeneratedKeys="true" keyProperty="id">
+        INSERT INTO board_image (member_id, content_type, data, byte_size, created_at)
+        VALUES (#{memberId}, #{contentType}, #{data}, #{byteSize}, NOW())
+    </insert>
+
+    <select id="findById" resultType="com.sb.web.board.domain.BoardImage">
+        SELECT id, member_id, content_type, data, byte_size, created_at
+        FROM board_image
+        WHERE id = #{id}
+    </select>
+
+</mapper>