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

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

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.

Please note, the os.arch property will only give you the architecture of the JRE, not of the underlying os.

If you install a 32 bit jre on a 64 bit system, System.getProperty("os.arch") will return x86

In order to actually determine the underlying architecture, you will need to write some native code. See this post for more info (and a link to sample native code)

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();

    }

}