64-bit - 如何检测安装了哪种 JRE——32 位与 64 位

Question

在使用 NSIS 安装程序进行安装期间，我需要检查系统上安装了哪个 JRE(32 位与 64 位)。我已经知道我可以检查系统属性“sun.arch.data.model”，但这是特定于 Sun 的。我想知道是否有一个标准的解决方案。

Answer 1

可以使用“os.arch”属性检索正在使用的 JVM 架构:

System.getProperty("os.arch");

“os”部分似乎有点用词不当，或者最初的设计者可能没有预料到 JVM 会在他们不是为之编写的架构上运行。返回值似乎是 inconsistent .

NetBeans 安装程序团队是 tackling the issue JVM 与 OS 架构的对比。引用:

x64 bit : Java and System

Tracked as the Issue 143434.

Currently we using x64 bit of JVM to determine if system (and thus Platform.getHardwareArch()) is 64-bit or not. This is definitely wrong since it is possible to run 32bit JVM on 64bit system. We should find a solution to check OS real 64-bitness in case of running on 32-bit JVM.

• for Windows it can be done using WindowsRegistry.IsWow64Process()
• for Linux - by checking 'uname -m/-p' == x86_64
• for Solaris it can be done using e.g. 'isainfo -b'
• for Mac OSX it can't be done using uname arguments, probably it can be solved by creating of 64-bit binary and executing on the platform... (unfortunately, this does not work:( I've created binary only with x86_64 and ppc64 arch and it was successfully executed on Tiger..)
• for Generic Unix support - it is not clear as well... likely checking for the same 'uname -m/-p' / 'getconf LONG_BIT' and comparing it with some possible 64-bit values (x86_64, x64, amd64, ia64).

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来自不同 JVM 的示例属性，均在 64 位 Ubuntu 8.0.4 上运行:

32 位 IBM 1.5:

java.vendor=IBM Corporation
java.vendor.url=http://www.ibm.com/
java.version=1.5.0
java.vm.info=J2RE 1.5.0 IBM J9 2.3 Linux x86-32 j9vmxi3223-20061001 (JIT enabled)
J9VM - 20060915_08260_lHdSMR
JIT  - 20060908_1811_r8
GC   - 20060906_AA
java.vm.name=IBM J9 VM
java.vm.specification.name=Java Virtual Machine Specification
java.vm.specification.vendor=Sun Microsystems Inc.
java.vm.specification.version=1.0
java.vm.vendor=IBM Corporation
java.vm.version=2.3
os.arch=x86
os.name=Linux
os.version=2.6.24-23-generic
sun.arch.data.model=32

64 位 Sun 1.6:

java.vendor=Sun Microsystems Inc.
java.vendor.url=http://java.sun.com/
java.vendor.url.bug=http://java.sun.com/cgi-bin/bugreport.cgi
java.version=1.6.0_05
java.vm.info=mixed mode
java.vm.name=Java HotSpot(TM) 64-Bit Server VM
java.vm.specification.name=Java Virtual Machine Specification
java.vm.specification.vendor=Sun Microsystems Inc.
java.vm.specification.version=1.0
java.vm.vendor=Sun Microsystems Inc.
java.vm.version=10.0-b19
os.arch=amd64
os.name=Linux
os.version=2.6.24-23-generic
sun.arch.data.model=64

64 位 GNU 1.5:

java.vendor=Free Software Foundation, Inc.
java.vendor.url=http://gcc.gnu.org/java/
java.version=1.5.0
java.vm.info=GNU libgcj 4.2.4 (Ubuntu 4.2.4-1ubuntu3)
java.vm.name=GNU libgcj
java.vm.specification.name=Java(tm) Virtual Machine Specification
java.vm.specification.vendor=Sun Microsystems Inc.
java.vm.specification.version=1.0
java.vm.vendor=Free Software Foundation, Inc.
java.vm.version=4.2.4 (Ubuntu 4.2.4-1ubuntu3)
os.arch=x86_64
os.name=Linux
os.version=2.6.24-23-generic

(GNU 版本不报告“sun.arch.data.model”属性；可能其他 JVM 也不报告。)