JNI を使用せずに Java でシステム パフォーマンス メトリクスを取得するにはどうすればよいですか?

public class SystemInfoMonitor {

    public static void main(String[] args) {
        // Runtime class methods for memory information
        int availableProcessors = Runtime.getRuntime().availableProcessors();
        long freeMemory = Runtime.getRuntime().freeMemory();
        long maxMemory = Runtime.getRuntime().maxMemory();
        long totalMemory = Runtime.getRuntime().totalMemory();

        // File class methods for disk usage information (requires Java 1.6+)
        File[] roots = File.listRoots();
        for (File root : roots) {
            long totalSpace = root.getTotalSpace();
            long freeSpace = root.getFreeSpace();
            long usableSpace = root.getUsableSpace();
        }

        // Print the collected information
        System.out.println("Available processors: " + availableProcessors);
        System.out.println("Free memory (bytes): " + freeMemory);
        System.out.println("Maximum memory (bytes): " + (maxMemory == Long.MAX_VALUE ? "no limit" : maxMemory));
        System.out.println("Total memory available to JVM (bytes): " + totalMemory);
        System.out.println("Disk usage information:");
        for (File root : roots) {
            System.out.println("File system root: " + root.getAbsolutePath());
            System.out.println("Total space (bytes): " + totalSpace);
            System.out.println("Free space (bytes): " + freeSpace);
            System.out.println("Usable space (bytes): " + usableSpace);
        }
    }
}