java监控JVM的内存使用情况等

     以下的程序监控参数的代码，有些是从网络上获取的，此处进行一个记录是为了以后如果要用到方便记录。

1、引入jar包，为了获取一些cpu的使用率等信息

<dependency>

<groupId>com.github.oshi</groupId>

<artifactId>oshi-core</artifactId>

<version>3.12.2</version>

</dependency>

<dependency>

<groupId>net.java.dev.jna</groupId>

<artifactId>jna</artifactId>

<version>5.2.0</version>

</dependency>

<dependency>

<groupId>net.java.dev.jna</groupId>

<artifactId>jna-platform</artifactId>

<version>5.2.0</version>

</dependency>

2、编写代码

/**
 * 系统监控
 *
 * @author huan.fu
 * @date 2018/12/3 - 18:44
 */
@Component
public class SystemMonitor {

  @PostConstruct
  public void init() {
    Executors.newSingleThreadScheduledExecutor().scheduleAtFixedRate(() -> {
      try {

        SystemInfo systemInfo = new SystemInfo();

        OperatingSystemMXBean osmxb = (OperatingSystemMXBean) ManagementFactory.getOperatingSystemMXBean();
        MemoryMXBean memoryMXBean = ManagementFactory.getMemoryMXBean();
        //椎内存使用情况
        MemoryUsage memoryUsage = memoryMXBean.getHeapMemoryUsage();

        //初始的总内存
        long initTotalMemorySize = memoryUsage.getInit();
        //最大可用内存
        long maxMemorySize = memoryUsage.getMax();
        //已使用的内存
        long usedMemorySize = memoryUsage.getUsed();

        // 操作系统
        String osName = System.getProperty("os.name");
        // 总的物理内存
        String totalMemorySize = new DecimalFormat("#.##").format(osmxb.getTotalPhysicalMemorySize() / 1024.0 / 1024 / 1024) + "G";
        // 剩余的物理内存
        String freePhysicalMemorySize = new DecimalFormat("#.##").format(osmxb.getFreePhysicalMemorySize() / 1024.0 / 1024 / 1024) + "G";
        // 已使用的物理内存
        String usedMemory = new DecimalFormat("#.##").format((osmxb.getTotalPhysicalMemorySize() - osmxb.getFreePhysicalMemorySize()) / 1024.0 / 1024 / 1024) + "G";
        // 获得线程总数
        ThreadGroup parentThread;
        for (parentThread = Thread.currentThread().getThreadGroup(); parentThread.getParent() != null; parentThread = parentThread.getParent()) {

        }

        int totalThread = parentThread.activeCount();

        // 磁盘使用情况
        File[] files = File.listRoots();
        for (File file : files) {
          String total = new DecimalFormat("#.#").format(file.getTotalSpace() * 1.0 / 1024 / 1024 / 1024) + "G";
          String free = new DecimalFormat("#.#").format(file.getFreeSpace() * 1.0 / 1024 / 1024 / 1024) + "G";
          String un = new DecimalFormat("#.#").format(file.getUsableSpace() * 1.0 / 1024 / 1024 / 1024) + "G";
          String path = file.getPath();
          System.err.println(path + "总:" + total + ",可用空间:" + un + ",空闲空间:" + free);
          System.err.println("=============================================");
        }


        System.err.println("操作系统:" + osName);
        System.err.println("程序启动时间:" + new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date(ManagementFactory.getRuntimeMXBean().getStartTime())));
        System.err.println("pid:" + System.getProperty("PID"));
        System.err.println("cpu核数:" + Runtime.getRuntime().availableProcessors());
        printlnCpuInfo(systemInfo);
        System.err.println("JAVA_HOME:" + System.getProperty("java.home"));
        System.err.println("JAVA_VERSION:" + System.getProperty("java.version"));
        System.err.println("USER_HOME:" + System.getProperty("user.home"));
        System.err.println("USER_NAME:" + System.getProperty("user.name"));
        System.err.println("初始的总内存(JVM):" + new DecimalFormat("#.#").format(initTotalMemorySize * 1.0 / 1024 / 1024) + "M");
        System.err.println("最大可用内存(JVM):" + new DecimalFormat("#.#").format(maxMemorySize * 1.0 / 1024 / 1024) + "M");
        System.err.println("已使用的内存(JVM):" + new DecimalFormat("#.#").format(usedMemorySize * 1.0 / 1024 / 1024) + "M");
        System.err.println("总的物理内存:" + totalMemorySize);
        System.err.println("总的物理内存:" + new DecimalFormat("#.##").format(systemInfo.getHardware().getMemory().getTotal() * 1.0 / 1024 / 1024 / 1024) + "M");
        System.err.println("剩余的物理内存:" + freePhysicalMemorySize);
        System.err.println("剩余的物理内存:" + new DecimalFormat("#.##").format(systemInfo.getHardware().getMemory().getAvailable() * 1.0 / 1024 / 1024 / 1024) + "M");
        System.err.println("已使用的物理内存:" + usedMemory);
        System.err.println("已使用的物理内存:" + new DecimalFormat("#.##").format((systemInfo.getHardware().getMemory().getTotal() - systemInfo.getHardware().getMemory().getAvailable()) * 1.0 / 1024 / 1024 / 1024) + "M");
        System.err.println("总线程数:" + totalThread);
        System.err.println("===========================");
      } catch (Exception e) {
        e.printStackTrace();
      }
    }, 0, 60, TimeUnit.SECONDS);
  }

  /**
   * 打印 CPU　信息
   *
   * @param systemInfo
   */
  private void printlnCpuInfo(SystemInfo systemInfo) throws InterruptedException {
    CentralProcessor processor = systemInfo.getHardware().getProcessor();
    long[] prevTicks = processor.getSystemCpuLoadTicks();
    // 睡眠1s
    TimeUnit.SECONDS.sleep(1);
    long[] ticks = processor.getSystemCpuLoadTicks();
    long nice = ticks[CentralProcessor.TickType.NICE.getIndex()] - prevTicks[CentralProcessor.TickType.NICE.getIndex()];
    long irq = ticks[CentralProcessor.TickType.IRQ.getIndex()] - prevTicks[CentralProcessor.TickType.IRQ.getIndex()];
    long softirq = ticks[CentralProcessor.TickType.SOFTIRQ.getIndex()] - prevTicks[CentralProcessor.TickType.SOFTIRQ.getIndex()];
    long steal = ticks[CentralProcessor.TickType.STEAL.getIndex()] - prevTicks[CentralProcessor.TickType.STEAL.getIndex()];
    long cSys = ticks[CentralProcessor.TickType.SYSTEM.getIndex()] - prevTicks[CentralProcessor.TickType.SYSTEM.getIndex()];
    long user = ticks[CentralProcessor.TickType.USER.getIndex()] - prevTicks[CentralProcessor.TickType.USER.getIndex()];
    long iowait = ticks[CentralProcessor.TickType.IOWAIT.getIndex()] - prevTicks[CentralProcessor.TickType.IOWAIT.getIndex()];
    long idle = ticks[CentralProcessor.TickType.IDLE.getIndex()] - prevTicks[CentralProcessor.TickType.IDLE.getIndex()];
    long totalCpu = user + nice + cSys + idle + iowait + irq + softirq + steal;
    System.err.println("cpu核数:" + processor.getLogicalProcessorCount());
    System.err.println("cpu系统使用率:" + new DecimalFormat("#.##%").format(cSys * 1.0 / totalCpu));
    System.err.println("cpu用户使用率:" + new DecimalFormat("#.##%").format(user * 1.0 / totalCpu));
    System.err.println("cpu当前等待率:" + new DecimalFormat("#.##%").format(iowait * 1.0 / totalCpu));
    System.err.println("cpu当前空闲率:" + new DecimalFormat("#.##%").format(idle * 1.0 / totalCpu));
    System.err.format("CPU load: %.1f%% (counting ticks)%n", processor.getSystemCpuLoadBetweenTicks() * 100);
    System.err.format("CPU load: %.1f%% (OS MXBean)%n", processor.getSystemCpuLoad() * 100);
  }
}      

3、获取更多系统信息，参考如下网址

​​ https://github.com/oshi/oshi​​