This "detail" is not abstracted away when interacting with the Java Native Interface. 32-bit DLLs can't be loaded with a 64-bit JVM (and vice versa). So this is quite essential information for anyone using JNI. It's a pity that there seems to be no portable way to obtain this info. One way is to first try loading a 32-bit version of the DLL, and if it fails, try the 64-bit version, etc. Ugly! – Joonas Pulakka Apr 30 '10 at 7:17 |
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Sun has a Java System property to determine the bitness of the JVM: 32 or 64:
sun.arch.data.model=32 // 32 bit JVM
sun.arch.data.model=64 // 64 bit JVM
You can use
System.getProperty("sun.arch.data.model")
to determine if its 32/64 from the program.
From the sun.docs:
When writing Java code, how do I distinguish between 32 and 64-bit operation?
There's no public API that allows you to distinguish between 32 and 64-bit operation. Think of 64-bit as just another platform in the write once, run anywhere tradition. However, if you'd like to write code which is platform specific (shame on you), the system property sun.arch.data.model has the value "32", "64", or "unknown".
The only good reason is if your java code is dependent upon native libraries and your code needs to determine which version (32 or 64bit) to load on startup.
Note by me : 这个仅在HotSpot JVM上可用
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System.out.println(System.getProperty("java.vm.name"));
Note by me : 这个不好说，也许能返回带有64bit的标识，
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Copy from ServerFault:
4 down vote accepted | Here (from the Sun release notes) is the answer I was looking for, at least for how to ensure the JDK server is up and running: jre\bin\server\
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