[Developer] #424 add Java MCP client demo tab

src/main/java/com/cloudhandson/vpdbackoffice/domain/mcp/McpClientDemoResult.java

@@ -0,0 +1,12 @@
+package com.cloudhandson.vpdbackoffice.domain.mcp;
+
+public record McpClientDemoResult(
+    String contextPath,
+    String messageUrl,
+    String selectedTool,
+    String initializeResponse,
+    String toolsListResponse,
+    String toolsCallResponse,
+    String status
+) {
+}

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

@@ -0,0 +1,144 @@
+package com.cloudhandson.vpdbackoffice.service;
+
+import com.cloudhandson.vpdbackoffice.config.BackofficeProperties;
+import com.cloudhandson.vpdbackoffice.domain.mcp.McpClientDemoResult;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import java.net.URI;
+import java.time.Duration;
+import org.springframework.boot.web.client.RestTemplateBuilder;
+import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.MediaType;
+import org.springframework.stereotype.Service;
+import org.springframework.web.client.RestTemplate;
+import org.springframework.web.util.UriComponentsBuilder;
+
+@Service
+public class McpClientDemoService {
+
+  private final BackofficeProperties properties;
+  private final ObjectMapper objectMapper;
+  private final RestTemplate restTemplate;
+
+  public McpClientDemoService(
+      BackofficeProperties properties,
+      ObjectMapper objectMapper,
+      RestTemplateBuilder restTemplateBuilder
+  ) {
+    this.properties = properties;
+    this.objectMapper = objectMapper;
+    this.restTemplate = restTemplateBuilder
+        .setConnectTimeout(Duration.ofSeconds(5))
+        .setReadTimeout(Duration.ofSeconds(15))
+        .build();
+  }
+
+  public McpClientDemoResult run(
+      String serverOrigin,
+      String contextPath,
+      String toolName,
+      String bearerToken,
+      int limit
+  ) {
+    String normalizedContextPath = normalizeContextPath(contextPath);
+    URI messageUri = messageUri(serverOrigin, normalizedContextPath);
+
+    JsonNode initializeResponse = post(messageUri, initializeRequest(1));
+    JsonNode toolsListResponse = post(messageUri, toolsListRequest(2));
+    JsonNode toolsCallResponse = null;
+    if (hasText(toolName) && hasText(bearerToken)) {
+      toolsCallResponse = post(messageUri, toolsCallRequest(3, toolName.trim(), bearerToken.trim(), normalizeLimit(limit)));
+    }
+
+    return new McpClientDemoResult(
+        normalizedContextPath,
+        messageUri.toString(),
+        hasText(toolName) ? toolName.trim() : "",
+        pretty(initializeResponse),
+        pretty(toolsListResponse),
+        toolsCallResponse == null ? "Bearer Token이 없어 tools/call은 실행하지 않았습니다." : pretty(toolsCallResponse),
+        toolsCallResponse == null ? "TOOLS_LIST_ONLY" : "SUCCESS"
+    );
+  }
+
+  private JsonNode post(URI uri, ObjectNode request) {
+    HttpHeaders headers = new HttpHeaders();
+    headers.setContentType(MediaType.APPLICATION_JSON);
+    headers.setBasicAuth(properties.security().adminUser(), properties.security().adminPassword());
+    String response = restTemplate.postForObject(uri, new HttpEntity<>(request, headers), String.class);
+    try {
+      return objectMapper.readTree(response);
+    } catch (Exception e) {
+      throw new AppException("MCP client 응답 JSON 파싱 실패: " + e.getMessage());
+    }
+  }
+
+  private URI messageUri(String serverOrigin, String contextPath) {
+    String path = "default".equals(contextPath) ? "/mcp/messages" : "/mcp/" + contextPath + "/messages";
+    return UriComponentsBuilder.fromUriString(serverOrigin)
+        .path(path)
+        .build()
+        .toUri();
+  }
+
+  private ObjectNode initializeRequest(int id) {
+    ObjectNode request = request(id, "initialize");
+    request.set("params", objectMapper.createObjectNode());
+    return request;
+  }
+
+  private ObjectNode toolsListRequest(int id) {
+    ObjectNode request = request(id, "tools/list");
+    request.set("params", objectMapper.createObjectNode());
+    return request;
+  }
+
+  private ObjectNode toolsCallRequest(int id, String toolName, String bearerToken, int limit) {
+    ObjectNode request = request(id, "tools/call");
+    ObjectNode params = objectMapper.createObjectNode();
+    params.put("name", toolName);
+    ObjectNode arguments = objectMapper.createObjectNode();
+    arguments.put("bearerToken", bearerToken);
+    arguments.put("limit", limit);
+    params.set("arguments", arguments);
+    request.set("params", params);
+    return request;
+  }
+
+  private ObjectNode request(int id, String method) {
+    ObjectNode request = objectMapper.createObjectNode();
+    request.put("jsonrpc", "2.0");
+    request.put("id", id);
+    request.put("method", method);
+    return request;
+  }
+
+  private String normalizeContextPath(String contextPath) {
+    String normalized = contextPath == null || contextPath.isBlank() ? "default" : contextPath.trim();
+    if (!normalized.matches("[A-Za-z0-9][A-Za-z0-9_-]{0,63}")) {
+      throw new AppException("MCP context path는 영문/숫자로 시작하고 영문/숫자/_/-만 사용할 수 있습니다: " + contextPath);
+    }
+    return normalized.toLowerCase();
+  }
+
+  private int normalizeLimit(int limit) {
+    if (limit < 1) {
+      return 50;
+    }
+    return Math.min(limit, 500);
+  }
+
+  private boolean hasText(String value) {
+    return value != null && !value.isBlank();
+  }
+
+  private String pretty(JsonNode node) {
+    try {
+      return objectMapper.writerWithDefaultPrettyPrinter().writeValueAsString(node);
+    } catch (Exception e) {
+      return String.valueOf(node);
+    }
+  }
+}

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

@@ -0,0 +1,64 @@
+package com.cloudhandson.vpdbackoffice.web;
+
+import com.cloudhandson.vpdbackoffice.service.McpClientDemoService;
+import com.cloudhandson.vpdbackoffice.service.McpToolRegistry;
+import jakarta.servlet.http.HttpServletRequest;
+import java.util.List;
+import org.springframework.dao.DataAccessException;
+import org.springframework.stereotype.Controller;
+import org.springframework.ui.Model;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.servlet.support.ServletUriComponentsBuilder;
+
+@Controller
+public class McpClientDemoController {
+
+  private final McpToolRegistry toolRegistry;
+  private final McpClientDemoService demoService;
+
+  public McpClientDemoController(McpToolRegistry toolRegistry, McpClientDemoService demoService) {
+    this.toolRegistry = toolRegistry;
+    this.demoService = demoService;
+  }
+
+  @GetMapping("/mcp-client-demo")
+  public String page(Model model) {
+    addTools(model);
+    return "mcp-client-demo";
+  }
+
+  @PostMapping("/mcp-client-demo")
+  public String run(
+      @RequestParam(defaultValue = "vpd-live") String contextPath,
+      @RequestParam(defaultValue = "") String toolName,
+      @RequestParam(defaultValue = "") String bearerToken,
+      @RequestParam(defaultValue = "50") int limit,
+      HttpServletRequest request,
+      Model model
+  ) {
+    addTools(model);
+    try {
+      String serverOrigin = ServletUriComponentsBuilder.fromRequestUri(request)
+          .replacePath(null)
+          .replaceQuery(null)
+          .build()
+          .toUriString();
+      model.addAttribute("result", demoService.run(serverOrigin, contextPath, toolName, bearerToken, limit));
+    } catch (Exception e) {
+      model.addAttribute("errorMessage", e.getMessage());
+    }
+    return "fragments/mcp-client-demo-result :: result";
+  }
+
+  private void addTools(Model model) {
+    try {
+      model.addAttribute("tools", toolRegistry.listTools());
+    } catch (DataAccessException e) {
+      RuntimeErrorMessage message = RuntimeErrorMessages.dataAccess(e);
+      model.addAttribute("tools", List.of());
+      model.addAttribute("runtimeError", message);
+    }
+  }
+}