如何从Java代码中找到应用程序可用的内核数量？

#1楼

在安装Cygwin的Windows上可以使用：

System.getenv("NUMBER_OF_PROCESSORS")

#2楼

如果要获取物理核的数量，可以运行cmd和terminal命令，然后解析输出以获取所需的信息。 下面显示了返回物理核心数量的函数。

private int getNumberOfCPUCores() {

OsValidator osValidator = new OsValidator();

String command = "";

if(osValidator.isMac()){

command = "sysctl -n machdep.cpu.core_count";

}else if(osValidator.isUnix()){

command = "lscpu";

}else if(osValidator.isWindows()){

command = "cmd /C WMIC CPU Get /Format:List";

}

Process process = null;

int numberOfCores = 0;

int sockets = 0;

try {

if(osValidator.isMac()){

String[] cmd = { "/bin/sh", "-c", command};

process = Runtime.getRuntime().exec(cmd);

}else{

process = Runtime.getRuntime().exec(command);

}

} catch (IOException e) {

e.printStackTrace();

}

BufferedReader reader = new BufferedReader(

new InputStreamReader(process.getInputStream()));

String line;

try {

while ((line = reader.readLine()) != null) {

if(osValidator.isMac()){

numberOfCores = line.length() > 0 ? Integer.parseInt(line) : 0;

}else if (osValidator.isUnix()) {

if (line.contains("Core(s) per socket:")) {

numberOfCores = Integer.parseInt(line.split("\\s+")[line.split("\\s+").length - 1]);

}

if(line.contains("Socket(s):")){

sockets = Integer.parseInt(line.split("\\s+")[line.split("\\s+").length - 1]);

}

} else if (osValidator.isWindows()) {

if (line.contains("NumberOfCores")) {

numberOfCores = Integer.parseInt(line.split("=")[1]);

}

}

}

} catch (IOException e) {

e.printStackTrace();

}

if(osValidator.isUnix()){

return numberOfCores * sockets;

}

return numberOfCores;

}

OSValidator类：

public class OSValidator {

private static String OS = System.getProperty("os.name").toLowerCase();

public static void main(String[] args) {

System.out.println(OS);

if (isWindows()) {

System.out.println("This is Windows");

} else if (isMac()) {

System.out.println("This is Mac");

} else if (isUnix()) {

System.out.println("This is Unix or Linux");

} else if (isSolaris()) {

System.out.println("This is Solaris");

} else {

System.out.println("Your OS is not support!!");

}

}

public static boolean isWindows() {

return (OS.indexOf("win") >= 0);

}

public static boolean isMac() {

return (OS.indexOf("mac") >= 0);

}

public static boolean isUnix() {

return (OS.indexOf("nix") >= 0 || OS.indexOf("nux") >= 0 || OS.indexOf("aix") > 0 );

}

public static boolean isSolaris() {

return (OS.indexOf("sunos") >= 0);

}

public static String getOS(){

if (isWindows()) {

return "win";

} else if (isMac()) {

return "osx";

} else if (isUnix()) {

return "uni";

} else if (isSolaris()) {

return "sol";

} else {

return "err";

}

}

}

#3楼

int cores = Runtime.getRuntime().availableProcessors();

如果cores少于一个，则可能是处理器即将死机，或者JVM中存在严重的错误，或者Universe即将崩溃。

#4楼

这是找出CPU内核数量(以及许多其他信息)的另一种方法，但是此代码需要附加的依赖关系：

SystemInfo systemInfo = new SystemInfo();

HardwareAbstractionLayer hardwareAbstractionLayer = systemInfo.getHardware();

CentralProcessor centralProcessor = hardwareAbstractionLayer.getProcessor();

获取可用于处理的逻辑CPU的数量：

centralProcessor.getLogicalProcessorCount();

#5楼

public class CPUCores {

public static void main(String[] args) {

int processors = Runtime.getRuntime().availableProcessors();

System.out.println("CPU cores: " + processors);

}

}

输出CPU内核：8

请注意，此数字是可用于Java应用程序的内核总数。

参考Java Doc API

超线程