feat(mcp-server-filesystem): Introduce MCP prompts for file operations

Author: codeboyzhou

mcp-server-filesystem/src/main/java/com/github/mcp/examples/server/filesystem/McpPrompts.java

@@ -0,0 +1,94 @@
+package com.github.mcp.examples.server.filesystem;
+
+import io.modelcontextprotocol.server.McpServerFeatures;
+import io.modelcontextprotocol.server.McpSyncServer;
+import io.modelcontextprotocol.spec.McpSchema;
+
+import java.util.List;
+import java.util.Map;
+
+/**
+ * A class that defines MCP prompts to the MCP server.
+ *
+ * @author codeboyzhou
+ */
+public class McpPrompts {
+
+    /**
+     * Create a MCP prompt to read complete contents of a file.
+     * --------------------------------------------------------
+     * Prompt Arguments:
+     * path (string): The filepath to read, required.
+     * --------------------------------------------------------
+     * Prompt Return:
+     * "What is the complete contents of the file: /path/to/file.txt"
+     *
+     * @return {@link McpServerFeatures.SyncPromptSpecification}
+     */
+    public static McpServerFeatures.SyncPromptSpecification readFile() {
+        // Step 1: Create a prompt argument with name, description, and required flag.
+        McpSchema.PromptArgument path = new McpSchema.PromptArgument("path", "The filepath to read, required.", true);
+
+        // Step 2: Create a prompt with name, description, and arguments.
+        McpSchema.Prompt prompt = new McpSchema.Prompt("read_file", "Read complete contents of a file.", List.of(path));
+
+        // Step 3: Create a prompt specification with the prompt and the prompt handler.
+        return new McpServerFeatures.SyncPromptSpecification(prompt, (exchange, request) -> {
+            // Step 4: Create a prompt message with role and content.
+            Map<String, Object> arguments = request.arguments();
+            final String filepath = arguments.get("path").toString();
+            McpSchema.TextContent content = new McpSchema.TextContent(
+                String.format("What is the complete contents of the file: %s", filepath)
+            );
+            McpSchema.PromptMessage message = new McpSchema.PromptMessage(McpSchema.Role.USER, content);
+            return new McpSchema.GetPromptResult(prompt.description(), List.of(message));
+        });
+    }
+
+    /**
+     * Create a MCP prompt to list files of a directory.
+     * -------------------------------------------------
+     * Prompt Arguments:
+     * path (string): The directory path to list files, required.
+     * pattern (string): The file name pattern to match, optional, default is {@code ""}.
+     * recursive (boolean): Whether to list files recursively, optional, default is {@code false}.
+     * -------------------------------------------------
+     * Prompt Return:
+     * "List files in the directory: /path/to/directory, with file name pattern: *.txt, recursively: true"
+     *
+     * @return {@link McpServerFeatures.SyncPromptSpecification}
+     */
+    public static McpServerFeatures.SyncPromptSpecification listFiles() {
+        // Step 1: Create a prompt argument with name, description, and required flag.
+        McpSchema.PromptArgument path = new McpSchema.PromptArgument("path", "The directory path to list files, required.", true);
+        McpSchema.PromptArgument pattern = new McpSchema.PromptArgument("pattern", "The file name pattern to match, optional.", false);
+        McpSchema.PromptArgument recursive = new McpSchema.PromptArgument("recursive", "Whether to list files recursively, optional.", false);
+
+        // Step 2: Create a prompt with name, description, and arguments.
+        McpSchema.Prompt prompt = new McpSchema.Prompt("list_files", "List files of a directory.", List.of(path, pattern, recursive));
+
+        // Step 3: Create a prompt specification with the prompt and the prompt handler.
+        return new McpServerFeatures.SyncPromptSpecification(prompt, (exchange, request) -> {
+            // Step 4: Create a prompt message with role and content.
+            Map<String, Object> arguments = request.arguments();
+            McpSchema.TextContent content = new McpSchema.TextContent(
+                String.format("List files in the directory: %s, with file name pattern: %s, recursively: %s",
+                    arguments.get("path"), arguments.getOrDefault("pattern", ""), arguments.getOrDefault("recursive", false)
+                )
+            );
+            McpSchema.PromptMessage message = new McpSchema.PromptMessage(McpSchema.Role.USER, content);
+            return new McpSchema.GetPromptResult(prompt.description(), List.of(message));
+        });
+    }
+
+    /**
+     * Add all prompts to the MCP server.
+     *
+     * @param server The MCP server to add prompts to.
+     */
+    public static void addAllTo(McpSyncServer server) {
+        server.addPrompt(readFile());
+        server.addPrompt(listFiles());
+    }
+
+}

mcp-server-filesystem/src/main/java/com/github/mcp/examples/server/filesystem/McpSseServer.java

@@ -70,8 +70,9 @@ private void initialize() {
             .capabilities(serverCapabilities)
             .build();
 
-        // Add resources and tools to the MCP server
+        // Add resources, prompts, and tools to the MCP server
         McpResources.addAllTo(server);
+        McpPrompts.addAllTo(server);
         McpTools.addAllTo(server);
 
         // Start the HTTP server

mcp-server-filesystem/src/main/java/com/github/mcp/examples/server/filesystem/McpStdioServer.java

@@ -52,8 +52,9 @@ public static void main(String[] args) {
         // Initialize MCP server
         McpStdioServer mcpStdioServer = new McpStdioServer();
         mcpStdioServer.initialize();
-        // Add resources and tools to the MCP server
+        // Add resources, prompts, and tools to the MCP server
         McpResources.addAllTo(mcpStdioServer.server);
+        McpPrompts.addAllTo(mcpStdioServer.server);
         McpTools.addAllTo(mcpStdioServer.server);
     }
 

pom.xml

@@ -22,7 +22,7 @@
         <!--==================== maven plugin versions ====================-->
         <sortpom-maven-plugin.version>4.0.0</sortpom-maven-plugin.version>
         <!--==================== dependency versions ======================-->
-        <mcp-sdk.version>0.8.1</mcp-sdk.version>
+        <mcp-sdk.version>0.9.0</mcp-sdk.version>
         <jetty.version>12.0.18</jetty.version>
         <logback.version>1.5.18</logback.version>
     </properties>