[Developer] #618 add structured data browser

src/main/java/com/cloudhandson/vpdbackoffice/domain/structured/StructuredDataPreview.java

@@ -0,0 +1,12 @@
+package com.cloudhandson.vpdbackoffice.domain.structured;
+
+import java.util.List;
+import java.util.Map;
+
+public record StructuredDataPreview(
+    StructuredDataTable table,
+    List<String> columns,
+    List<Map<String, Object>> rows,
+    int rowLimit
+) {
+}

src/main/java/com/cloudhandson/vpdbackoffice/domain/structured/StructuredDataTable.java

@@ -0,0 +1,9 @@
+package com.cloudhandson.vpdbackoffice.domain.structured;
+
+public record StructuredDataTable(
+    String key,
+    String tableName,
+    String businessName,
+    String description
+) {
+}

src/main/java/com/cloudhandson/vpdbackoffice/service/StructuredDataService.java

@@ -0,0 +1,69 @@
+package com.cloudhandson.vpdbackoffice.service;
+
+import com.cloudhandson.vpdbackoffice.domain.structured.StructuredDataPreview;
+import com.cloudhandson.vpdbackoffice.domain.structured.StructuredDataTable;
+import java.util.List;
+import java.util.Map;
+import org.springframework.dao.DataAccessException;
+import org.springframework.jdbc.core.JdbcTemplate;
+import org.springframework.stereotype.Service;
+
+@Service
+public class StructuredDataService {
+
+  private static final String OWNER = "POC_2";
+  private static final int ROW_LIMIT = 50;
+  private static final List<StructuredDataTable> TABLES = List.of(
+      new StructuredDataTable("customers", "KB_CUSTOMERS", "고객원장", "고객 기본정보"),
+      new StructuredDataTable("products", "KB_PRODUCTS", "상품원장", "보험상품 마스터"),
+      new StructuredDataTable("contracts", "KB_CONTRACTS", "계약원장", "보험계약 정보"),
+      new StructuredDataTable("coverages", "KB_COVERAGES", "담보원장", "보장·특약 정보"),
+      new StructuredDataTable("claims", "KB_CLAIMS", "청구원장", "보험금 청구·지급 정보"),
+      new StructuredDataTable("external-holdings", "KB_EXTERNAL_HOLDINGS", "외부보유정보 원장", "타사·외부 가입·보유 정보"),
+      new StructuredDataTable("stakeholders", "KB_STAKEHOLDERS", "이해관계자 원장", "역할·담당자 매핑"));
+
+  private final JdbcTemplate jdbcTemplate;
+
+  public StructuredDataService(JdbcTemplate jdbcTemplate) {
+    this.jdbcTemplate = jdbcTemplate;
+  }
+
+  public List<StructuredDataTable> tables() {
+    return TABLES;
+  }
+
+  public String defaultKey() {
+    return TABLES.getFirst().key();
+  }
+
+  public StructuredDataTable requireTable(String key) {
+    return TABLES.stream()
+        .filter(table -> table.key().equals(key))
+        .findFirst()
+        .orElseThrow(() -> new AppException("선택할 수 없는 정형 데이터 테이블입니다."));
+  }
+
+  public StructuredDataPreview preview(String key) {
+    StructuredDataTable table = requireTable(key);
+    try {
+      List<String> columns = jdbcTemplate.query(
+          """
+              SELECT column_name
+              FROM all_tab_columns
+              WHERE owner = ?
+                AND table_name = ?
+              ORDER BY column_id
+              """,
+          (resultSet, rowNum) -> resultSet.getString(1), OWNER, table.tableName());
+      if (columns.isEmpty()) {
+        throw new AppException("정형 데이터 테이블의 컬럼 정보를 찾을 수 없습니다.");
+      }
+
+      List<Map<String, Object>> rows = jdbcTemplate.queryForList(
+          "SELECT * FROM " + OWNER + "." + table.tableName() + " WHERE ROWNUM <= ?", ROW_LIMIT);
+      return new StructuredDataPreview(table, columns, rows, ROW_LIMIT);
+    } catch (DataAccessException exception) {
+      throw new AppException("정형 데이터를 조회할 수 없습니다. POC_2 조회 권한과 대상 테이블 상태를 확인하세요.");
+    }
+  }
+}

src/main/java/com/cloudhandson/vpdbackoffice/web/StructuredDataController.java

@@ -0,0 +1,34 @@
+package com.cloudhandson.vpdbackoffice.web;
+
+import com.cloudhandson.vpdbackoffice.service.AppException;
+import com.cloudhandson.vpdbackoffice.service.StructuredDataService;
+import org.springframework.stereotype.Controller;
+import org.springframework.ui.Model;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+
+@Controller
+public class StructuredDataController {
+
+  private final StructuredDataService structuredDataService;
+
+  public StructuredDataController(StructuredDataService structuredDataService) {
+    this.structuredDataService = structuredDataService;
+  }
+
+  @GetMapping("/structured-data")
+  public String structuredData(
+      @RequestParam(required = false) String table,
+      Model model
+  ) {
+    String selectedKey = table == null || table.isBlank() ? structuredDataService.defaultKey() : table;
+    model.addAttribute("tables", structuredDataService.tables());
+    model.addAttribute("selectedKey", selectedKey);
+    try {
+      model.addAttribute("preview", structuredDataService.preview(selectedKey));
+    } catch (AppException exception) {
+      model.addAttribute("errorMessage", exception.getMessage());
+    }
+    return "structured-data";
+  }
+}