我想用Java监视以下系统信息：
可用磁盘空间（免费/总计）
*请注意，我的意思是整个系统可用的整体内存，而不仅仅是JVM。
我正在寻找一种不依赖于我自己的代码调用外部程序或使用JNI的跨平台解决方案（Linux，Mac和Windows）。虽然这些是可行的选择，但如果有人已经拥有更好的解决方案，我宁愿不自己维护特定于操作系统的代码。
如果有一个免费的库可以通过可靠的跨平台方式实现这一点，那就太棒了（即使它进行外部调用或使用本机代码本身）。
非常感谢任何建议。
为了澄清，我想获得整个系统的当前CPU使用率，而不仅仅是Java进程。
SIGAR API在一个软件包中提供了我正在寻找的所有功能，因此它是迄今为止我的问题的最佳答案。但是，由于它是根据GPL许可的，我不能将它用于我的原始目的（封闭源，商业产品）。 Hyperic可能会将SIGAR许可用于商业用途，但我还没有调查过。对于我的GPL项目，我将来肯定会考虑SIGAR。
根据我目前的需求，我倾向于以下内容：
OperatingSystemMXBean.getSystemLoadAverage() / OperatingSystemMXBean.getAvailableProcessors()（每个CPU的平均负载）OperatingSystemMXBean.getTotalPhysicalMemorySize()和OperatingSystemMXBean.getFreePhysicalMemorySize() File.getTotalSpace()和File.getUsableSpace() 限制：
getSystemLoadAverage()和磁盘空间查询方法仅在Java 6下可用。此外，某些JMX功能可能并非对所有平台都可用（即，已报告getSystemLoadAverage()在Windows上返回-1）
虽然最初是根据GPL许可的，但has been changed到Apache 2.0，通常可用于闭源商业产品。
答案 0 :(得分：65)
与我提到的in this post一致。我建议你使用SIGAR API。我在自己的一个应用程序中使用SIGAR API，这很棒。你会发现它是稳定的，得到很好的支持，并且充满了有用的例子。它是开源的，带有 GPL 2 Apache 2.0许可证。看看这个。我觉得它会满足你的需求。
使用Java和Sigar API，您可以获得内存，CPU，磁盘，负载平均，网络接口信息和指标，进程表信息，路由信息等。
答案 1 :(得分：51)
以下据称可以获得CPU和RAM。有关详细信息，请参阅ManagementFactory。
import java.lang.management.ManagementFactory;
import java.lang.management.OperatingSystemMXBean;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
private static void printUsage() {
OperatingSystemMXBean operatingSystemMXBean = ManagementFactory.getOperatingSystemMXBean();
for (Method method : operatingSystemMXBean.getClass().getDeclaredMethods()) {
method.setAccessible(true);
if (method.getName().startsWith("get")
&& Modifier.isPublic(method.getModifiers())) {
Object value;
try {
value = method.invoke(operatingSystemMXBean);
} catch (Exception e) {
value = e;
} // try
System.out.println(method.getName() + " = " + value);
} // if
} // for
}
答案 2 :(得分：35)
在JDK 1.7中，您可以通过com.sun.management.OperatingSystemMXBean获得系统CPU和内存使用量。这与java.lang.management.OperatingSystemMXBean不同。
long getCommittedVirtualMemorySize()
Returns the amount of virtual memory that is guaranteed to be available to the running process in bytes, or -1 if this operation is not supported.
long getFreePhysicalMemorySize()
Returns the amount of free physical memory in bytes.
long getFreeSwapSpaceSize()
Returns the amount of free swap space in bytes.
double getProcessCpuLoad()
Returns the "recent cpu usage" for the Java Virtual Machine process.
long getProcessCpuTime()
Returns the CPU time used by the process on which the Java virtual machine is running in nanoseconds.
double getSystemCpuLoad()
Returns the "recent cpu usage" for the whole system.
long getTotalPhysicalMemorySize()
Returns the total amount of physical memory in bytes.
long getTotalSwapSpaceSize()
Returns the total amount of swap space in bytes.
答案 3 :(得分：19)
这完全适用于我，没有任何外部API，只有本机Java隐藏功能：）
import com.sun.management.OperatingSystemMXBean;
...
OperatingSystemMXBean osBean = ManagementFactory.getPlatformMXBean(
OperatingSystemMXBean.class);
// What % CPU load this current JVM is taking, from 0.0-1.0
System.out.println(osBean.getProcessCpuLoad());
// What % load the overall system is at, from 0.0-1.0
System.out.println(osBean.getSystemCpuLoad());
答案 4 :(得分：14)
要获得所用CPU的百分比，您只需要一些简单的数学：
MBeanServerConnection mbsc = ManagementFactory.getPlatformMBeanServer();
OperatingSystemMXBean osMBean = ManagementFactory.newPlatformMXBeanProxy(
mbsc, ManagementFactory.OPERATING_SYSTEM_MXBEAN_NAME, OperatingSystemMXBean.class);
long nanoBefore = System.nanoTime();
long cpuBefore = osMBean.getProcessCpuTime();
// Call an expensive task, or sleep if you are monitoring a remote process
long cpuAfter = osMBean.getProcessCpuTime();
long nanoAfter = System.nanoTime();
long percent;
if (nanoAfter > nanoBefore)
percent = ((cpuAfter-cpuBefore)*100L)/
(nanoAfter-nanoBefore);
else percent = 0;
System.out.println("Cpu usage: "+percent+"%");
注意：您必须导入com.sun.management.OperatingSystemMXBean而不是java.lang.management.OperatingSystemMXBean。
答案 5 :(得分：8)
对于磁盘空间，如果您使用的是Java 6，则可以在File上使用getTotalSpace和getFreeSpace方法。如果您不使用Java 6，我相信您可以使用Apache Commons IO来获取某些内容。
我不知道有任何跨平台方式来获取CPU使用率或内存使用率。我担心。
答案 6 :(得分：6)
很多已经可以通过JMX获得。使用Java 5，JMX是内置的，它们包含一个带JDK的JMX控制台查看器。
如果您在自己的运行时需要此信息，可以使用JMX手动监视，或从Java调用JMX命令。
答案 7 :(得分：4)
/* YOU CAN TRY THIS TOO */
import java.io.File;
import java.lang.management.ManagementFactory;
// import java.lang.management.OperatingSystemMXBean;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.lang.management.RuntimeMXBean;
import java.io.*;
import java.net.*;
import java.util.*;
import java.io.LineNumberReader;
import java.lang.management.ManagementFactory;
import com.sun.management.OperatingSystemMXBean;
import java.lang.management.ManagementFactory;
import java.util.Random;
public class Pragati
{
public static void printUsage(Runtime runtime)
{
long total, free, used;
int mb = 1024*1024;
total = runtime.totalMemory();
free = runtime.freeMemory();
used = total - free;
System.out.println("\nTotal Memory: " + total / mb + "MB");
System.out.println(" Memory Used: " + used / mb + "MB");
System.out.println(" Memory Free: " + free / mb + "MB");
System.out.println("Percent Used: " + ((double)used/(double)total)*100 + "%");
System.out.println("Percent Free: " + ((double)free/(double)total)*100 + "%");
}
public static void log(Object message)
{
System.out.println(message);
}
public static int calcCPU(long cpuStartTime, long elapsedStartTime, int cpuCount)
{
long end = System.nanoTime();
long totalAvailCPUTime = cpuCount * (end-elapsedStartTime);
long totalUsedCPUTime = ManagementFactory.getThreadMXBean().getCurrentThreadCpuTime()-cpuStartTime;
//log("Total CPU Time:" + totalUsedCPUTime + " ns.");
//log("Total Avail CPU Time:" + totalAvailCPUTime + " ns.");
float per = ((float)totalUsedCPUTime*100)/(float)totalAvailCPUTime;
log( per);
return (int)per;
}
static boolean isPrime(int n)
{
// 2 is the smallest prime
if (n <= 2)
{
return n == 2;
}
// even numbers other than 2 are not prime
if (n % 2 == 0)
{
return false;
}
// check odd divisors from 3
// to the square root of n
for (int i = 3, end = (int)Math.sqrt(n); i <= end; i += 2)
{
if (n % i == 0)
{
return false;
}
}
return true;
}
public static void main(String [] args)
{
int mb = 1024*1024;
int gb = 1024*1024*1024;
/* PHYSICAL MEMORY USAGE */
System.out.println("\n**** Sizes in Mega Bytes ****\n");
com.sun.management.OperatingSystemMXBean operatingSystemMXBean = (com.sun.management.OperatingSystemMXBean)ManagementFactory.getOperatingSystemMXBean();
//RuntimeMXBean runtimeMXBean = ManagementFactory.getRuntimeMXBean();
//operatingSystemMXBean = (com.sun.management.OperatingSystemMXBean) ManagementFactory.getOperatingSystemMXBean();
com.sun.management.OperatingSystemMXBean os = (com.sun.management.OperatingSystemMXBean)
java.lang.management.ManagementFactory.getOperatingSystemMXBean();
long physicalMemorySize = os.getTotalPhysicalMemorySize();
System.out.println("PHYSICAL MEMORY DETAILS \n");
System.out.println("total physical memory : " + physicalMemorySize / mb + "MB ");
long physicalfreeMemorySize = os.getFreePhysicalMemorySize();
System.out.println("total free physical memory : " + physicalfreeMemorySize / mb + "MB");
/* DISC SPACE DETAILS */
File diskPartition = new File("C:");
File diskPartition1 = new File("D:");
File diskPartition2 = new File("E:");
long totalCapacity = diskPartition.getTotalSpace() / gb;
long totalCapacity1 = diskPartition1.getTotalSpace() / gb;
double freePartitionSpace = diskPartition.getFreeSpace() / gb;
double freePartitionSpace1 = diskPartition1.getFreeSpace() / gb;
double freePartitionSpace2 = diskPartition2.getFreeSpace() / gb;
double usablePatitionSpace = diskPartition.getUsableSpace() / gb;
System.out.println("\n**** Sizes in Giga Bytes ****\n");
System.out.println("DISC SPACE DETAILS \n");
//System.out.println("Total C partition size : " + totalCapacity + "GB");
//System.out.println("Usable Space : " + usablePatitionSpace + "GB");
System.out.println("Free Space in drive C: : " + freePartitionSpace + "GB");
System.out.println("Free Space in drive D: : " + freePartitionSpace1 + "GB");
System.out.println("Free Space in drive E: " + freePartitionSpace2 + "GB");
if(freePartitionSpace <= totalCapacity%10 || freePartitionSpace1 <= totalCapacity1%10)
{
System.out.println(" !!!alert!!!!");
}
else
System.out.println("no alert");
Runtime runtime;
byte[] bytes;
System.out.println("\n \n**MEMORY DETAILS ** \n");
// Print initial memory usage.
runtime = Runtime.getRuntime();
printUsage(runtime);
// Allocate a 1 Megabyte and print memory usage
bytes = new byte[1024*1024];
printUsage(runtime);
bytes = null;
// Invoke garbage collector to reclaim the allocated memory.
runtime.gc();
// Wait 5 seconds to give garbage collector a chance to run
try {
Thread.sleep(5000);
} catch(InterruptedException e) {
e.printStackTrace();
return;
}
// Total memory will probably be the same as the second printUsage call,
// but the free memory should be about 1 Megabyte larger if garbage
// collection kicked in.
printUsage(runtime);
for(int i = 0; i < 30; i++)
{
long start = System.nanoTime();
// log(start);
//number of available processors;
int cpuCount = ManagementFactory.getOperatingSystemMXBean().getAvailableProcessors();
Random random = new Random(start);
int seed = Math.abs(random.nextInt());
log("\n \n CPU USAGE DETAILS \n\n");
log("Starting Test with " + cpuCount + " CPUs and random number:" + seed);
int primes = 10000;
//
long startCPUTime = ManagementFactory.getThreadMXBean().getCurrentThreadCpuTime();
start = System.nanoTime();
while(primes != 0)
{
if(isPrime(seed))
{
primes--;
}
seed++;
}
float cpuPercent = calcCPU(startCPUTime, start, cpuCount);
log("CPU USAGE : " + cpuPercent + " % ");
try
{
Thread.sleep(1000);
}
catch (InterruptedException e) {}
}
try
{
Thread.sleep(500);
}`enter code here`
catch (Exception ignored) { }
}
}
答案 8 :(得分：3)
以下代码仅适用于Linux（可能是Unix），但它适用于实际项目。
private double getAverageValueByLinux() throws InterruptedException {
try {
long delay = 50;
List<Double> listValues = new ArrayList<Double>();
for (int i = 0; i < 100; i++) {
long cput1 = getCpuT(pattern);
Thread.sleep(delay);
long cput2 = getCpuT(pattern);
double cpuproc = (1000d * (cput2 - cput1)) / (double) delay;
listValues.add(cpuproc);
}
listValues.remove(0);
listValues.remove(listValues.size() - 1);
double sum = 0.0;
for (Double double1 : listValues) {
sum += double1;
}
return sum / listValues.size();
} catch (Exception e) {
e.printStackTrace();
return 0;
}
}
private long getCpuT(Pattern pattern) throws FileNotFoundException, IOException {
BufferedReader reader = new BufferedReader(new FileReader("/proc/stat"));
String line = reader.readLine();
Matcher m = pattern.matcher(line);
long cpuUser = 0;
long cpuSystem = 0;
if (m.find()) {
cpuUser = Long.parseLong(m.group(1));
cpuSystem = Long.parseLong(m.group(3));
}
return cpuUser + cpuSystem;
}
答案 9 :(得分：3)
将批处理文件“Pc.bat”设为， typeperf -sc 1“\ mukit \ processor（_Total）\ %% Processor Time”
您可以使用类MProcess，
/* *Md. Mukit Hasan *CSE-JU,35 **/ import java.io.*;public class MProcessor {
public MProcessor() { String s; try { Process ps = Runtime.getRuntime().exec("Pc.bat"); BufferedReader br = new BufferedReader(new InputStreamReader(ps.getInputStream())); while((s = br.readLine()) != null) { System.out.println(s); } } catch( Exception ex ) { System.out.println(ex.toString()); } }
}
然后在一些字符串操作之后，您将获得CPU使用。您可以将相同的过程用于其他任务。
- Mukit Hasan
答案 10 :(得分：2)
2008年接受的答案推荐了SIGAR。但是，作为2014年的评论（@Alvaro）说：
使用Sigar时要小心，x64机器上有问题... Sigar 1.6.4 is crashing: EXCEPTION_ACCESS_VIOLATION，似乎是图书馆 自2010年以来未更新
我的建议是使用https://github.com/oshi/oshi