java linux获取实时cpu

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;

public class CPUMonitor {
    public static void main(String[] args) {
        try {
            long[] prevCpuInfo = readCpuInfo();
            Thread.sleep(1000); // 等待1秒
            long[] currCpuInfo = readCpuInfo();

            double cpuUsage = calculateCpuUsage(prevCpuInfo, currCpuInfo);
            System.out.println("CPU Usage: " + cpuUsage + "%");
        } catch (InterruptedException | IOException e) {
            e.printStackTrace();
        }
    }

    private static long[] readCpuInfo() throws IOException {
        BufferedReader reader = new BufferedReader(new FileReader("/proc/stat"));
        String line = reader.readLine();
        reader.close();

        if (line != null && line.startsWith("cpu ")) {
            String[] parts = line.split("\\s+");
            long[] cpuInfo = new long[parts.length - 1];
            for (int i = 1; i < parts.length; i++) {
                cpuInfo[i - 1] = Long.parseLong(parts[i]);
            }
            return cpuInfo;
        }
        throw new IOException("Failed to read CPU info from /proc/stat");
    }

    private static double calculateCpuUsage(long[] prevCpuInfo, long[] currCpuInfo) {
        long totalPrev = 0, totalCurr = 0;
        for (int i = 0; i < prevCpuInfo.length; i++) {
            totalPrev += prevCpuInfo[i];
            totalCurr += currCpuInfo[i];
        }

        long totalDelta = totalCurr - totalPrev;
        long idleDelta = currCpuInfo[3] - prevCpuInfo[3];

        return (totalDelta - idleDelta) * 100.0 / totalDelta;
    }
}