systemresrc.java

实现linux性能分析 如：cpu利用率

import java.io.*;
import java.util.*;
public class SystemResrc {
	public static void main (String[] args) throws  FileNotFoundException ,IOException , InterruptedException{
		RandomAccessFile filecpu=new RandomAccessFile("/proc/stat","r");
		RandomAccessFile filemem=new RandomAccessFile("/proc/meminfo","r");
		RandomAccessFile filenet=new RandomAccessFile("/proc/net/dev","r");
		int i,j;
		float cputm,memrt,netrcv,nettra;
//		String cpu;
		
		while(true){
			filecpu.seek(0);
			filenet.seek(0);
			while(filenet.readLine().charAt(4)!='l');
			
			Scanner cpustat1=new Scanner(filecpu.readLine());
			Scanner netstat1=new Scanner(filenet.readLine());
			filecpu.seek(0);
			filenet.seek(0);
			Thread.sleep(1000);
			Scanner cpustat2=new Scanner(filecpu.readLine());
			while(filenet.readLine().charAt(4)!='l');
			Scanner netstat2=new Scanner(filenet.readLine());

			cpustat1.next();cpustat2.next();
			i=3;j=0;cputm=0;memrt=0;

			netstat1.next();netstat2.next();
			netrcv=netstat2.nextLong()-netstat1.nextLong();
			while(j++<7){netstat1.nextLong();netstat2.nextLong();}
			nettra=netstat2.nextLong()-netstat1.nextLong();
			System.out.println(""+netrcv+"&"+nettra);//net

			while(i-->0)
				cputm+=(cpustat2.nextLong()-cpustat1.nextLong());

			cputm/=(cputm+cpustat2.nextLong()-cpustat1.nextLong());
			cputm*=100;
			System.out.println(""+cputm+"%");//cpu
			
			Scanner mem1=new Scanner(filemem.readLine());
			Scanner mem2=new Scanner(filemem.readLine());
			Scanner mem3=new Scanner(filemem.readLine());
			Scanner mem4=new Scanner(filemem.readLine());
			filemem.seek(0);
			mem1.next();
			mem2.next();
			mem3.next();
			mem4.next();
			memrt+=mem2.nextLong()+mem3.nextLong()+mem4.nextLong();
			memrt/=mem1.nextLong();
			memrt=1-memrt;
			System.out.println(""+memrt);//mem

					
		}
		
	}
}