refactor(util): Replace JsonHelper with ObjectMappers for JSON and YAML processing

codeboyzhou · codeboyzhou · commit 5255ad396400 · 2025-08-11T09:46:51.000+08:00
diff --git a/src/main/java/com/github/codeboyzhou/mcp/declarative/McpServers.java b/src/main/java/com/github/codeboyzhou/mcp/declarative/McpServers.java
@@ -52,11 +52,13 @@ public void startSseServer(McpSseServerInfo serverInfo) {
 
   public void startServer(String configFileName) {
     Assert.notNull(configFileName, "configFileName must not be null");
-    doStartServer(new YAMLConfigurationLoader(configFileName).getConfig());
+    YAMLConfigurationLoader configLoader = new YAMLConfigurationLoader(configFileName);
+    doStartServer(configLoader.loadConfig());
   }
 
   public void startServer() {
-    doStartServer(new YAMLConfigurationLoader().getConfig());
+    YAMLConfigurationLoader configLoader = new YAMLConfigurationLoader();
+    doStartServer(configLoader.loadConfig());
   }
 
   private void doStartServer(McpServerConfiguration configuration) {
diff --git a/src/main/java/com/github/codeboyzhou/mcp/declarative/common/BufferQueue.java b/src/main/java/com/github/codeboyzhou/mcp/declarative/common/BufferQueue.java
@@ -1,6 +1,6 @@
 package com.github.codeboyzhou.mcp.declarative.common;
 
-import com.github.codeboyzhou.mcp.declarative.util.JsonHelper;
+import com.github.codeboyzhou.mcp.declarative.util.ObjectMappers;
 import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.Executors;
 import java.util.concurrent.LinkedBlockingQueue;
@@ -33,7 +33,7 @@ public BufferQueue() {
   public void submit(T component) {
     try {
       queue.put(component);
-      logger.debug("Component submitted to queue: {}", JsonHelper.toJson(component));
+      logger.debug("Component submitted to queue: {}", ObjectMappers.toJson(component));
     } catch (InterruptedException e) {
       Thread.currentThread().interrupt();
     }
@@ -48,7 +48,8 @@ public void consume(Consumer<T> consumer) {
                 while (!Thread.interrupted()) {
                   T component = queue.take();
                   consumer.accept(component);
-                  logger.debug("Component consumed from queue: {}", JsonHelper.toJson(component));
+                  logger.debug(
+                      "Component consumed from queue: {}", ObjectMappers.toJson(component));
                   TimeUnit.MILLISECONDS.sleep(delayMillis);
                 }
               } catch (InterruptedException e) {
diff --git a/src/main/java/com/github/codeboyzhou/mcp/declarative/configuration/YAMLConfigurationLoader.java b/src/main/java/com/github/codeboyzhou/mcp/declarative/configuration/YAMLConfigurationLoader.java
@@ -1,49 +1,35 @@
 package com.github.codeboyzhou.mcp.declarative.configuration;
 
-import com.fasterxml.jackson.databind.ObjectMapper;
-import com.fasterxml.jackson.dataformat.yaml.YAMLFactory;
 import com.github.codeboyzhou.mcp.declarative.exception.McpServerException;
-import java.io.IOException;
+import com.github.codeboyzhou.mcp.declarative.util.ObjectMappers;
 import java.net.URISyntaxException;
 import java.net.URL;
-import java.nio.file.FileSystems;
 import java.nio.file.Path;
 import java.nio.file.Paths;
-import java.nio.file.StandardWatchEventKinds;
-import java.nio.file.WatchEvent;
-import java.nio.file.WatchKey;
-import java.nio.file.WatchService;
-import java.util.List;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 public final class YAMLConfigurationLoader {
 
   private static final Logger logger = LoggerFactory.getLogger(YAMLConfigurationLoader.class);
 
-  private static final ObjectMapper YAML_MAPPER = new ObjectMapper(new YAMLFactory());
-
   private static final String CONFIG_FILE_NAME = "mcp-server.yml";
 
-  private static final String WATCH_THREAD_NAME = "McpServerConfigFileWatcher";
-
   private final String configFileName;
 
-  private WatchService watchService;
-
-  private McpServerConfiguration config;
-
   public YAMLConfigurationLoader(String configFileName) {
     this.configFileName = configFileName;
-    initializeWatchService();
-    loadConfig();
   }
 
   public YAMLConfigurationLoader() {
     this(CONFIG_FILE_NAME);
   }
 
-  public McpServerConfiguration getConfig() {
+  public McpServerConfiguration loadConfig() {
+    Path configFilePath = getConfigFilePath(configFileName);
+    McpServerConfiguration config =
+        ObjectMappers.fromYaml(configFilePath.toFile(), McpServerConfiguration.class);
+    logger.info("Configuration loaded successfully from file: {}", configFileName);
     return config;
   }
 
@@ -57,52 +43,7 @@ private Path getConfigFilePath(String fileName) {
       return Paths.get(configFileUrl.toURI());
     } catch (URISyntaxException e) {
       // should never happen
-      return null;
-    }
-  }
-
-  private void initializeWatchService() {
-    try {
-      Path configFilePath = getConfigFilePath(configFileName);
-      assert configFilePath != null;
-      Path parentPath = configFilePath.getParent();
-      watchService = FileSystems.getDefault().newWatchService();
-      parentPath.register(watchService, StandardWatchEventKinds.ENTRY_MODIFY);
-
-      Thread watchThread = new Thread(this::watchConfigFile, WATCH_THREAD_NAME);
-      watchThread.setDaemon(true);
-      watchThread.start();
-    } catch (IOException e) {
-      logger.error("Failed to initialize configuration file watch service", e);
-    }
-  }
-
-  private void watchConfigFile() {
-    try {
-      while (true) {
-        WatchKey watchKey = watchService.take();
-        List<WatchEvent<?>> watchEvents = watchKey.pollEvents();
-        for (WatchEvent<?> event : watchEvents) {
-          if (event.context().toString().equals(configFileName)) {
-            loadConfig();
-          }
-        }
-        watchKey.reset();
-      }
-    } catch (InterruptedException e) {
-      Thread.currentThread().interrupt();
-      logger.error("Configuration file watch service interrupted", e);
-    }
-  }
-
-  private void loadConfig() {
-    try {
-      Path configFilePath = getConfigFilePath(configFileName);
-      assert configFilePath != null;
-      config = YAML_MAPPER.readValue(configFilePath.toFile(), McpServerConfiguration.class);
-      logger.info("Configuration loaded successfully");
-    } catch (IOException e) {
-      logger.error("Failed to reload configuration", e);
+      throw new McpServerException("Invalid configuration file path: " + fileName, e);
     }
   }
 }
diff --git a/src/main/java/com/github/codeboyzhou/mcp/declarative/server/factory/McpServerPromptFactory.java b/src/main/java/com/github/codeboyzhou/mcp/declarative/server/factory/McpServerPromptFactory.java
@@ -6,7 +6,7 @@
 import com.github.codeboyzhou.mcp.declarative.annotation.McpPromptParam;
 import com.github.codeboyzhou.mcp.declarative.annotation.McpPrompts;
 import com.github.codeboyzhou.mcp.declarative.common.BufferQueue;
-import com.github.codeboyzhou.mcp.declarative.util.JsonHelper;
+import com.github.codeboyzhou.mcp.declarative.util.ObjectMappers;
 import com.github.codeboyzhou.mcp.declarative.util.StringHelper;
 import com.github.codeboyzhou.mcp.declarative.util.TypeConverter;
 import com.google.inject.Inject;
@@ -47,7 +47,7 @@ public McpServerFeatures.AsyncPromptSpecification create(Class<?> clazz, Method
     final String description = resolveComponentAttributeValue(promptMethod.description());
     List<McpSchema.PromptArgument> promptArguments = createPromptArguments(method);
     McpSchema.Prompt prompt = new McpSchema.Prompt(name, title, description, promptArguments);
-    logger.debug("Registering prompt: {}", JsonHelper.toJson(prompt));
+    logger.debug("Registering prompt: {}", ObjectMappers.toJson(prompt));
     return new McpServerFeatures.AsyncPromptSpecification(
         prompt,
         (exchange, request) ->
diff --git a/src/main/java/com/github/codeboyzhou/mcp/declarative/server/factory/McpServerResourceFactory.java b/src/main/java/com/github/codeboyzhou/mcp/declarative/server/factory/McpServerResourceFactory.java
@@ -5,7 +5,7 @@
 import com.github.codeboyzhou.mcp.declarative.annotation.McpResource;
 import com.github.codeboyzhou.mcp.declarative.annotation.McpResources;
 import com.github.codeboyzhou.mcp.declarative.common.BufferQueue;
-import com.github.codeboyzhou.mcp.declarative.util.JsonHelper;
+import com.github.codeboyzhou.mcp.declarative.util.ObjectMappers;
 import com.github.codeboyzhou.mcp.declarative.util.StringHelper;
 import com.google.inject.Inject;
 import com.google.inject.Injector;
@@ -47,7 +47,7 @@ public McpServerFeatures.AsyncResourceSpecification create(Class<?> clazz, Metho
             .mimeType(res.mimeType())
             .annotations(new McpSchema.Annotations(List.of(res.roles()), res.priority()))
             .build();
-    logger.debug("Registering resource: {}", JsonHelper.toJson(resource));
+    logger.debug("Registering resource: {}", ObjectMappers.toJson(resource));
     return new McpServerFeatures.AsyncResourceSpecification(
         resource,
         (exchange, request) ->
diff --git a/src/main/java/com/github/codeboyzhou/mcp/declarative/server/factory/McpServerToolFactory.java b/src/main/java/com/github/codeboyzhou/mcp/declarative/server/factory/McpServerToolFactory.java
@@ -9,7 +9,7 @@
 import com.github.codeboyzhou.mcp.declarative.annotation.McpTools;
 import com.github.codeboyzhou.mcp.declarative.common.BufferQueue;
 import com.github.codeboyzhou.mcp.declarative.enums.JsonSchemaDataType;
-import com.github.codeboyzhou.mcp.declarative.util.JsonHelper;
+import com.github.codeboyzhou.mcp.declarative.util.ObjectMappers;
 import com.github.codeboyzhou.mcp.declarative.util.StringHelper;
 import com.github.codeboyzhou.mcp.declarative.util.TypeConverter;
 import com.google.inject.Inject;
@@ -58,7 +58,7 @@ public McpServerFeatures.AsyncToolSpecification create(Class<?> clazz, Method me
             .description(description)
             .inputSchema(paramSchema)
             .build();
-    logger.debug("Registering tool: {}", JsonHelper.toJson(tool));
+    logger.debug("Registering tool: {}", ObjectMappers.toJson(tool));
     return McpServerFeatures.AsyncToolSpecification.builder()
         .tool(tool)
         .callHandler(
diff --git a/src/main/java/com/github/codeboyzhou/mcp/declarative/util/JsonHelper.java b/src/main/java/com/github/codeboyzhou/mcp/declarative/util/JsonHelper.java
diff --git a/src/main/java/com/github/codeboyzhou/mcp/declarative/util/ObjectMappers.java b/src/main/java/com/github/codeboyzhou/mcp/declarative/util/ObjectMappers.java
@@ -0,0 +1,38 @@
+package com.github.codeboyzhou.mcp.declarative.util;
+
+import com.fasterxml.jackson.core.JsonFactory;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.dataformat.yaml.YAMLFactory;
+import com.github.codeboyzhou.mcp.declarative.exception.McpServerException;
+import java.io.File;
+import java.io.IOException;
+import org.jetbrains.annotations.VisibleForTesting;
+
+public final class ObjectMappers {
+
+  public static final ObjectMapper JSON_MAPPER = new ObjectMapper(new JsonFactory());
+
+  private static final ObjectMapper YAML_MAPPER = new ObjectMapper(new YAMLFactory());
+
+  @VisibleForTesting
+  ObjectMappers() {
+    throw new UnsupportedOperationException("Utility class should not be instantiated");
+  }
+
+  public static String toJson(Object object) {
+    try {
+      return JSON_MAPPER.writeValueAsString(object);
+    } catch (JsonProcessingException e) {
+      throw new McpServerException("Error converting object to JSON", e);
+    }
+  }
+
+  public static <T> T fromYaml(File yamlFile, Class<T> valueType) {
+    try {
+      return YAML_MAPPER.readValue(yamlFile, valueType);
+    } catch (IOException e) {
+      throw new McpServerException("Error reading YAML file: " + yamlFile.getAbsolutePath(), e);
+    }
+  }
+}
diff --git a/src/test/java/com/github/codeboyzhou/mcp/declarative/util/ObjectMappersTest.java b/src/test/java/com/github/codeboyzhou/mcp/declarative/util/ObjectMappersTest.java
@@ -7,14 +7,14 @@
 import com.github.codeboyzhou.mcp.declarative.exception.McpServerException;
 import org.junit.jupiter.api.Test;
 
-class JsonHelperTest {
+class ObjectMappersTest {
 
   record TestClass(String name, int age) {}
 
   @Test
   void testNewInstance() {
     UnsupportedOperationException e =
-        assertThrows(UnsupportedOperationException.class, JsonHelper::new);
+        assertThrows(UnsupportedOperationException.class, ObjectMappers::new);
     assertEquals("Utility class should not be instantiated", e.getMessage());
   }
 
@@ -23,10 +23,10 @@ void testToJson() {
     assertDoesNotThrow(
         () -> {
           TestClass testObject = new TestClass("test", 18);
-          assertEquals("{\"name\":\"test\",\"age\":18}", JsonHelper.toJson(testObject));
+          assertEquals("{\"name\":\"test\",\"age\":18}", ObjectMappers.toJson(testObject));
         });
 
-    McpServerException e = assertThrows(McpServerException.class, () -> JsonHelper.toJson(this));
+    McpServerException e = assertThrows(McpServerException.class, () -> ObjectMappers.toJson(this));
     assertEquals("Error converting object to JSON", e.getMessage());
   }
 }

Original file line number	Diff line number	Diff line change
`@@ -52,11 +52,13 @@ public void startSseServer(McpSseServerInfo serverInfo) {`
`52`	`52`
`53`	`53`	`public void startServer(String configFileName) {`
`54`	`54`	`Assert.notNull(configFileName, "configFileName must not be null");`
`55`		`- doStartServer(new YAMLConfigurationLoader(configFileName).getConfig());`
	`55`	`+ YAMLConfigurationLoader configLoader = new YAMLConfigurationLoader(configFileName);`
	`56`	`+ doStartServer(configLoader.loadConfig());`
`56`	`57`	`}`
`57`	`58`
`58`	`59`	`public void startServer() {`
`59`		`- doStartServer(new YAMLConfigurationLoader().getConfig());`
	`60`	`+ YAMLConfigurationLoader configLoader = new YAMLConfigurationLoader();`
	`61`	`+ doStartServer(configLoader.loadConfig());`
`60`	`62`	`}`
`61`	`63`
`62`	`64`	`private void doStartServer(McpServerConfiguration configuration) {`