java - Check if Windows XP or later in Java?

Question

What would be the easiest way to check that the operating system running my Java application is Windows XP or later?

EDIT: I know about System.getProperty("os.name") but I don't know the best way and/or most efficient way to check what version of Windows is running. Ideally, I would also like to make it future proof so that if another version of Windows is released I don't need to change the code.

Answer 1

mkyong 给出了一个教程：http ://www.mkyong.com/java/how-to-detect-os-in-java-systemgetpropertyosname/

它依赖于System.getProperty("os.name")

Answer 2

由于 Windows 可靠地将其版本信息报告为float，因此可以通过了解每个 Windows 版本并进行比较来计算“XP 或更高版本”。

速记：

// Is this XP or higher?
// Well, XP Reports as 5.1 (32-bit) or 5.2 (64-bit).  All higher OSs use a higher version
final boolean XP_OR_HIGHER = (Float.parseFloat(System.getProperty("os.version")) >= 5.1f);

但是由于解析系统值可能引发异常，再加上 XP 是 EOL 的事实，并且更有可能有人正在寻找更新的操作系统比较......这是一种更全面的方法。

注意：对于 Windows 10，所有版本都报告为10.0无论 Microsoft 在版本之间发生了多少变化。如需更详细的信息，您必须查看注册表（另请参阅HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ReleaseId）。

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

public class WinVer {
    enum WindowsType {
        /*
         * Keep descending for best match, or rewrite using comparitor
         */
        WINDOWS_10(10.0f),
        WINDOWS_8_1(6.3f),
        WINDOWS_8(6.2f),
        WINDOWS_7(6.1f),
        WINDOWS_VISTA(6.0f),
        WINDOWS_XP_64(5.2f),
        WINDOWS_XP(5.1f),
        WINDOWS_ME(4.9f),
        WINDOWS_2000(5.0f),
        WINDOWS_NT(4.0f), // or Win95
        UNKNOWN(0.0f);

        private float version;

        WindowsType(float version) {
            this.version = version;
        }

        public static float parseFloat(String versionString) {
            float version = 0.0f;
            /*
             * Sanitize the String.
             *
             * Windows version is generally formatted x.x (e.g. 3.1, 6.1, 10.0)
             * This format can later be treated as a float for comparison.
             * Since we have no guarantee the String will be formatted properly, we'll sanitize it.
             * For more complex comparisons, try a SemVer library, such as zafarkhaja/jsemver. <3
             */
            List<String> parts = Arrays.asList(versionString.replaceAll("[^\\d.]", "").split("\\."));

            // Fix .add(...), .remove(...), see https://stackoverflow.com/a/5755510/3196753
            parts = new ArrayList<>(parts);

            // Fix length
            while (parts.size() != 2) {
                if (parts.size() > 2) {
                    // pop off last element
                    parts.remove(parts.size() - 1);
                }
                if (parts.size() < 2) {
                    // push zero
                    parts.add("0");
                }
            }

            String sanitized = String.join(".", parts.toArray(new String[0]));
            try {
                version = Float.parseFloat(sanitized);
            } catch (NumberFormatException e) {
                System.err.println("ERROR: Something went wrong parsing " + sanitized + " as a float");
            }

            return version;
        }

        public static WindowsType match(float version) {
            WindowsType detectedType = UNKNOWN;

            // Warning: Iterates in order they were declared.  If you don't like this, write a proper comparator instead. <3
            for (WindowsType type : WindowsType.values()) {
                if (type.version >= version) {
                    detectedType = type;
                } else {
                    break;
                }
            }
            return detectedType;
        }

    }

    public static void main(String... args) {

        String osName = System.getProperty("os.name");
        String osVer = System.getProperty("os.version");

        if (osName.toLowerCase().startsWith("windows")) {
            System.out.println("Yes, you appear to be running windows");
            float windowsVersion = WindowsType.parseFloat(osVer);
            System.out.println(" - Windows version reported is: " + windowsVersion);
            WindowsType windowsType = WindowsType.match(windowsVersion);
            System.out.println(" - Windows type is detected as: " + windowsType);

            if(windowsVersion >= WindowsType.WINDOWS_XP.version) {
                System.out.println("Yes, this OS is Windows XP or higher.");
            } else {
                System.out.println("No, this OS is NOT Windows XP or higher.");
            }
        }
    }

}