jvm虚拟机内存储器状态查看

jvm虚拟机内存状态查看

import java.lang.Runtime;

public class Memory {
	public static void main(String args[]) {
		System.out.println("usage:");
		Memory m = new Memory();
		long t = m.showUsage();
		System.out.println("Total:" + t + " Bytes");
		long fr = m.freeMemory();
		// System.gc();
		System.out.println("Free:" + fr + " Bytes");
		long rem = t - fr;
		System.out.println("Occupied Space :" + rem + " Bytes");

		Runtime run = Runtime.getRuntime();
		long max = run.maxMemory();
		long total = run.totalMemory();
		long free = run.freeMemory();
		long usable = max - total + free;
		System.out.println("最大内存 = " + max);
		System.out.println("已分配内存 = " + total);
		System.out.println("已分配内存中的剩余空间 = " + free);
		System.out.println("最大可用内存 = " + usable);

	}

	public long showUsage() {
		long l = Runtime.getRuntime().totalMemory();
		return (l);
	}

	public long freeMemory() {
		long f = Runtime.getRuntime().freeMemory();
		return (f);
	}
}