如何使用从Java到Windows OS的系统调用来查找可用的系统内存，磁盘空间，CPU使用率

Question

how to find available system memory, disk space, cpu usage of windows OS using system calls from java?

*in windows operating system

wat i actually want to do is ,,, accept a file from client user and save the file in the server after checking the available space. my server and client are connected using a java tcp socket program!

Answer 1

You can get some limited information using the below program. This was already answered by some one else in the same forum and I am just reproducing the same.

import java.io.File;

public class MemoryInfo {
  public static void main(String[] args) {
    /* Total number of processors or cores available to the JVM */
    System.out.println("Available processors (cores): " + 
        Runtime.getRuntime().availableProcessors());

    /* Total amount of free memory available to the JVM */
    System.out.println("Free memory (bytes): " + 
        Runtime.getRuntime().freeMemory());

    /* This will return Long.MAX_VALUE if there is no preset limit */
    long maxMemory = Runtime.getRuntime().maxMemory();
    /* Maximum amount of memory the JVM will attempt to use */
    System.out.println("Maximum memory (bytes): " + 
        (maxMemory == Long.MAX_VALUE ? "no limit" : maxMemory));

    /* Total memory currently in use by the JVM */
    System.out.println("Total memory (bytes): " + 
        Runtime.getRuntime().totalMemory());

    /* Get a list of all filesystem roots on this system */
    File[] roots = File.listRoots();

    /* For each filesystem root, print some info */
    for (File root : roots) {
      System.out.println("File system root: " + root.getAbsolutePath());
      System.out.println("Total space (bytes): " + root.getTotalSpace());
      System.out.println("Free space (bytes): " + root.getFreeSpace());
      System.out.println("Usable space (bytes): " + root.getUsableSpace());
    }
  }
}