■ はじめに
https://blogs.yahoo.co.jp/dk521123/7968881.htmlの続き。
実装案
【1】コマンドを実行した方法 【2】com.sun.management.OperatingSystemMXBean を使った方法 【3】MBeanServer を使った方法
【1】コマンドの実行結果から取得する方法
Linuxの場合* vmstatコマンドでJavaコードから実行し、CPU情報を抽出する* vmstatコマンドについては、以下の関連記事を参照のこと。
https://blogs.yahoo.co.jp/dk521123/37259054.html
サンプル
import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.util.ArrayList; import java.util.LinkedHashMap; import java.util.List; import java.util.Map; public class Main { public static void main(String[] args) throws Exception { System.out.println("Test1"); List<Map<String, Long>> vmStatusValues = getVmStatusValues("vmstat"); System.out.println(); for (Map<String, Long> vmStatusValue : vmStatusValues) { for (Map.Entry<String, Long> map : vmStatusValue.entrySet()) { System.out.println(map.getKey() + " : " + map.getValue()); } } System.out.println(); System.out.println("Test2"); List<Map<String, Long>> vmStatusValues2 = getVmStatusValues("vmstat", "1", "3"); System.out.println(); for (Map<String, Long> vmStatusValue : vmStatusValues2) { for (Map.Entry<String, Long> map : vmStatusValue.entrySet()) { System.out.println(map.getKey() + " : " + map.getValue()); } } } private static List<Map<String, Long>> getVmStatusValues(String... commands) throws Exception { ProcessBuilder processBuilder = new ProcessBuilder(commands); try { Process process = processBuilder.start(); int result = process.waitFor(); System.out.println("Result Code : " + result); try (BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(process.getInputStream()))) { String line; String[] items = null; String[] valuses; List<Map<String, Long>> returnValues = new ArrayList<Map<String, Long>>(); int i = 0; while ((line = bufferedReader.readLine()) != null) { System.out.println("[DEBUG] " + line); i++; if (i == 1) { // Skip first line continue; } else if (i == 2) { items = line.trim().split("\\s+"); } else { if (items == null) { return returnValues; } valuses = line.trim().split("\\s+"); Map<String, Long> vmStatusValues = new LinkedHashMap<>(); int j = 0; for (String item : items) { Long value = Long.valueOf(valuses[j]); vmStatusValues.put(item, value); j++; } returnValues.add(vmStatusValues); } } return returnValues; } } catch (IOException | InterruptedException ex) { throw ex; } } }出力結果
Test1 Result Code : 0 [DEBUG] procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu----- [DEBUG] r b swpd free buff cache si so bi bo in cs us sy id wa st [DEBUG] 2 0 1093384 68964 40 255468 16 137 1921 403 446 548 19 3 78 0 0 r : 2 b : 0 swpd : 1093384 free : 68964 buff : 40 cache : 255468 si : 16 so : 137 bi : 1921 bo : 403 in : 446 cs : 548 us : 19 sy : 3 id : 78 wa : 0 st : 0 Test2 Result Code : 0 [DEBUG] procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu----- [DEBUG] r b swpd free buff cache si so bi bo in cs us sy id wa st [DEBUG] 3 0 1093384 67600 40 256484 16 137 1922 403 446 548 19 3 78 0 0 [DEBUG] 0 0 1093384 65988 40 258092 0 0 1636 0 980 1218 54 6 40 0 0 [DEBUG] 1 0 1093384 65864 40 258128 0 0 0 0 855 1267 54 4 42 0 0 r : 3 b : 0 swpd : 1093384 free : 67600 buff : 40 cache : 256484 si : 16 so : 137 bi : 1922 bo : 403 in : 446 cs : 548 us : 19 sy : 3 id : 78 wa : 0 st : 0 r : 0 b : 0 swpd : 1093384 free : 65988 buff : 40 cache : 258092 si : 0 so : 0 bi : 1636 bo : 0 in : 980 cs : 1218 us : 54 sy : 6 id : 40 wa : 0 st : 0 r : 1 b : 0 swpd : 1093384 free : 65864 buff : 40 cache : 258128 si : 0 so : 0 bi : 0 bo : 0 in : 855 cs : 1267 us : 54 sy : 4 id : 42 wa : 0 st : 0参考文献
https://stackoverflow.com/questions/6284384/get-memory-and-cpu-usage
【2】com.sun.management.OperatingSystemMXBean を使った方法
サンプル
import java.lang.management.ManagementFactory; public class Main { @SuppressWarnings("restriction") public static void main(String[] args) { com.sun.management.OperatingSystemMXBean operatingSystemMXBean = (com.sun.management.OperatingSystemMXBean) ManagementFactory.getOperatingSystemMXBean(); System.out.println("ProcessCpuLoad : " + operatingSystemMXBean.getProcessCpuLoad()); System.out.println("ProcessCpuTime : " + operatingSystemMXBean.getProcessCpuTime()); System.out.println("SystemCpuTime : " + operatingSystemMXBean.getSystemCpuLoad()); } }出力結果
ProcessCpuLoad : -1.0 ProcessCpuTime : 421875000 SystemCpuTime : -1.0参考文献
https://stackoverflow.com/questions/36647405/java-api-to-get-cpu-memory-usage-of-my-java-application
【3】MBeanServer を使った方法
サンプル
import java.lang.management.ManagementFactory; import javax.management.Attribute; import javax.management.AttributeList; import javax.management.InstanceNotFoundException; import javax.management.MBeanServer; import javax.management.MalformedObjectNameException; import javax.management.ObjectName; import javax.management.ReflectionException; public class Main { public static void main(String[] args) throws Exception { printCpuInfo(); } public static void printCpuInfo() throws InstanceNotFoundException, ReflectionException, MalformedObjectNameException, NullPointerException { MBeanServer mbeanServer = ManagementFactory.getPlatformMBeanServer(); ObjectName objectName = ObjectName.getInstance("java.lang:type=OperatingSystem"); AttributeList attributeList = mbeanServer.getAttributes(objectName, new String[] { "ProcessCpuLoad", "ProcessCpuTime", "SystemCpuLoad" }); if (attributeList.isEmpty()) { System.out.println("attributeList is Empty"); } for (Attribute attribute : attributeList.asList()) { System.out.println(attribute.getName() + " : " + attribute.getValue()); } } }出力結果
ProcessCpuLoad : 0.37238200554819395 ProcessCpuTime : 578125000 SystemCpuLoad : -1.0参考文献
https://stackoverflow.com/questions/18489273/how-to-get-percentage-of-cpu-usage-of-os-from-java
別解サンプル
import java.lang.management.ManagementFactory; import java.lang.management.OperatingSystemMXBean; import java.lang.reflect.Method; import java.lang.reflect.Modifier; public class Main { public static void main(String[] args) { printUsage(); } 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 ex) { value = ex; } System.out.println(method.getName() + " = " + value); } } } }出力結果
getCommittedVirtualMemorySize = 236544000 getFreePhysicalMemorySize = 2628100096 getFreeSwapSpaceSize = 2142429184 getProcessCpuLoad = -1.0 getProcessCpuTime = 515625000 getSystemCpuLoad = -1.0 getTotalPhysicalMemorySize = 8491581440 getTotalSwapSpaceSize = 10035085312参考文献
https://stackoverflow.com/questions/47177/how-do-i-monitor-the-computers-cpu-memory-and-disk-usage-in-java
