JVM MCP Server

Instructions

        Args:
            pid (str): 进程ID，使用字符串形式（如："12345"）
            option (Optional[str]): jstat选项，如gc、class、compiler等
            interval (str): 采样间隔（毫秒），使用字符串形式（如："1000"表示1秒）
            count (str): 采样次数，使用字符串形式（如："10"）

        Returns:
            Dict: 包含jstat执行结果的字典，包含以下字段：
                - raw_output (str): 原始输出
                - timestamp (float): 时间戳
                - success (bool): 是否成功
                - error (Optional[str]): 错误信息
        

Implementation Reference

• src/jvm_mcp_server/server.py:635-683 (handler)

  Main handler function for the 'get_jstat_output' MCP tool. Validates inputs (PID, interval, count), executes JstatCommand via the executor, and formats the response dictionary with raw output, success status, and error handling.

  @self.mcp.tool()
  def get_jstat_output(pid: str = "", 
                      option: Optional[str] = None, 
                      interval: str = "", 
                      count: str = "") -> Dict:
      """执行 jstat 监控命令
  
      Args:
          pid (str): 进程ID，使用字符串形式（如："12345"）
          option (Optional[str]): jstat选项，如gc、class、compiler等
          interval (str): 采样间隔（毫秒），使用字符串形式（如："1000"表示1秒）
          count (str): 采样次数，使用字符串形式（如："10"）
  
      Returns:
          Dict: 包含jstat执行结果的字典，包含以下字段：
              - raw_output (str): 原始输出
              - timestamp (float): 时间戳
              - success (bool): 是否成功
              - error (Optional[str]): 错误信息
      """
      try:
          validated_pid = self._validate_and_convert_id(pid if pid else None, "process ID")
          if validated_pid is None:
              return {
                  "raw_output": "",
                  "timestamp": time.time(),
                  "success": False,
                  "error": "Invalid process ID"
              }
          
          validated_interval = self._validate_and_convert_id(interval if interval else None, "interval")
          validated_count = self._validate_and_convert_id(count if count else None, "count")
          
      except ValueError as e:
          return {
              "raw_output": "",
              "timestamp": time.time(),
              "success": False,
              "error": str(e)
          }
      
      cmd = JstatCommand(self.executor, JstatFormatter())
      result = cmd.execute(str(validated_pid), option=option, interval=validated_interval, count=validated_count)
      return {
          "raw_output": result.get('output', ''),
          "timestamp": time.time(),
          "success": result.get('success', False),
          "error": result.get('error')
      }

• src/jvm_mcp_server/native/tools/jstat.py:6-48 (helper)

  Helper classes JstatCommand and JstatFormatter. JstatCommand constructs the jstat command line (jstat -option pid [interval [count]]). JstatFormatter formats the command result into a simple dictionary with success, output/error, and metadata.

  class JstatCommand(BaseCommand):
      """Jstat命令实现"""
  
      def __init__(self, executor, formatter):
          super().__init__(executor, formatter)
          self.timeout = 30
  
      def get_command(
              self,
              pid: str,
              option: Optional[str] = None,
              interval: Optional[int] = None,
              count: Optional[int] = None,
              *args,
              **kwargs) -> str:
          # option: gc, gccapacity, class, compiler, util, ...
          cmd = f'jstat'
          if option:
              cmd += f' -{option}'
          cmd += f' {pid}'
          if interval is not None:
              cmd += f' {interval}'
              if count is not None:
                  cmd += f' {count}'
          return cmd
  
  class JstatFormatter(OutputFormatter):
      """Jstat输出格式化器（仅文本输出）"""
  
      def format(self, result: CommandResult) -> Dict[str, Any]:
          if not result.success:
              return {
                  "success": False,
                  "error": result.error,
                  "timestamp": result.timestamp.isoformat()
                  }
          return {
              "success": True,
              "output": result.output,
              "execution_time": result.execution_time,
              "timestamp": result.timestamp.isoformat()
              }