How do you determine 32 or 64 bit architecture of Windows using Java?

Question

How do you determine 32 or 64 bit architecture of Windows using Java?

Answer 1

I used the command prompt (command --> wmic OS get OSArchitecture) to get the OS architecture. The following program helps get all the required parameters:

import java.io.*;

public class User {
    public static void main(String[] args) throws Exception {

        System.out.println("OS --> "+System.getProperty("os.name"));   //OS Name such as Windows/Linux

        System.out.println("JRE Architecture --> "+System.getProperty("sun.arch.data.model")+" bit.");       // JRE architecture i.e 64 bit or 32 bit JRE

        ProcessBuilder builder = new ProcessBuilder(
            "cmd.exe", "/c","wmic OS get OSArchitecture");
        builder.redirectErrorStream(true);
        Process p = builder.start();
        String result = getStringFromInputStream(p.getInputStream());

        if(result.contains("64"))
            System.out.println("OS Architecture --> is 64 bit");  //The OS Architecture
        else
            System.out.println("OS Architecture --> is 32 bit");

        }


    private static String getStringFromInputStream(InputStream is) {

        BufferedReader br = null;
        StringBuilder sb = new StringBuilder();

        String line;
        try {

            br = new BufferedReader(new InputStreamReader(is));
            while ((line = br.readLine()) != null) {
                sb.append(line);
            }

        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (br != null) {
                try {
                    br.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

        return sb.toString();

    }

}

Answer 2

(Only for Windows) Check if C:\Windows\SysWOW64 exists. if the directory exist, it is a 64 bit process. Else, it is a 32 bit process.

Answer 3

Maybe it 's not the best way, but it works.

All I do is get the "Enviroment Variable" which windows has configured for Program Files x86 folder. I mean Windows x64 have the folder (Program Files x86) and the x86 does not. Because a user can change the Program Files path in Enviroment Variables, or he/she may make a directory "Program Files (x86)" in C:\, I will not use the detection of the folder but the "Enviroment Path" of "Program Files (x86)" with the variable in windows registry.

public class getSystemInfo {

    static void suckOsInfo(){

    // Get OS Name (Like: Windows 7, Windows 8, Windows XP, etc.)
    String osVersion = System.getProperty("os.name");
    System.out.print(osVersion);

    String pFilesX86 = System.getenv("ProgramFiles(X86)");
    if (pFilesX86 !=(null)){
        // Put here the code to execute when Windows x64 are Detected
    System.out.println(" 64bit");
    }
    else{
        // Put here the code to execute when Windows x32 are Detected
    System.out.println(" 32bit");
    }

    System.out.println("Now getSystemInfo class will EXIT");
    System.exit(0);

    }

}

Answer 4

I don't exactly trust reading the os.arch system variable. While it works if a user is running a 64bit JVM on a 64bit system. It doesn't work if the user is running a 32bit JVM on a 64 bit system.

The following code works for properly detecting Windows 64-bit operating systems. On a Windows 64 bit system the environment variable "Programfiles(x86)" will be set. It will NOT be set on a 32-bit system and java will read it as null.

boolean is64bit = false;
if (System.getProperty("os.name").contains("Windows")) {
    is64bit = (System.getenv("ProgramFiles(x86)") != null);
} else {
    is64bit = (System.getProperty("os.arch").indexOf("64") != -1);
}

For other operating systems like Linux or Solaris or Mac we may see this problem as well. So this isn't a complete solution. For mac you are probably safe because apple locks down the JVM to match the OS. But Linux and Solaris, etc.. they may still use a 32-bit JVM on their 64-bit system. So use this with caution.

Answer 5

You can use the os.arch property in system properties to find out.

Properties pr = System.getProperties();
System.out.println(pr.getProperty("os.arch"));

If you are on 32 bit, it should show i386 or something

Answer 6

System.getProperty("os.arch");