InnoSetup: Detect if Java is 32-bit or 64-bit

Question

In InnoSetup I run this code:

J32 := ShellExec('', 'java', '-d32 -version', '', SW_HIDE, ewWaitUntilTerminated, ec);
J64 := ShellExec('', 'java', '-d64 -version', '', SW_HIDE, ewWaitUntilTerminated, ec);

Both J32 and J64 are True.

In command line:

> java -d32 -version
Error: This Java instance does not support a 32-bit JVM.
Please install the desired version.

> echo %errorlevel%
1

> java -d64 -version
java version "1.7.0"
Java(TM) SE Runtime Environment (build 1.7.0-b147)
Java HotSpot(TM) 64-Bit Server VM (build 21.0-b17, mixed mode)

> echo %errorlevel%
0

Why does ShellExec() ignore Params?

I tried Exec() also:

// this way
J32 := Exec('java', '-d32 -version', '', SW_HIDE, ewWaitUntilTerminated, ec);
// and this way
J32 := Exec('>', 'java -d32 -version', '', SW_HIDE, ewWaitUntilTerminated, ec);

They all return True, and ec = 1, despite the fact that I have a 64-bit java.

It seems that Exec and ShellExec return True because they succeed to run java, but they do not track the error code java returns.

ShellExec never waits for the process to complete. However, your second to last command (`Exec('java', '-d32 -version' ...`) looks fine. What was in `ec` after it ran? What was in `J32`? — David Schwartz, Nov 06 '11 at 14:55
Pascal Scripting: ShellExec documentation says that: "The Wait parameter specifies whether the function should return immediately or wait until the launched process has termimated or is idle." — utapyngo, Nov 06 '11 at 14:59
`ec = 1`. It is always 1 when the call is successful. `J32 = True` — utapyngo, Nov 06 '11 at 14:59
Possibly related to: http://stackoverflow.com/questions/2062020/how-can-i-tell-if-im-running-in-64-bit-jvm-or-32-bit-jvm — Gray, Nov 06 '11 at 16:16
@Gray: thanks, I know about this question. It asks, however, about detecting the JVM version from within the Java program. — utapyngo, Nov 07 '11 at 01:46

score 1 · Answer 1 · edited May 23 '17 at 11:54

The Inno Setup help states:

http://www.jrsoftware.org/ishelp/index.php?topic=setup_architecturesinstallin64bitmode

The System32 path returned by the {sys} constant maps to the 64-bit System directory by default when used in the [Dirs], [Files], [InstallDelete], [Run], [UninstallDelete], and [UninstallRun] sections. This is because Setup/Uninstall temporarily disables WOW64 file system redirection [external link] when files/directories are accessed by those sections. Elsewhere, System32 and {sys} map to the 32-bit System directory, as is normal in a 32-bit process.

So in 64-bit mode in the [Code] section, everything is 32-bit. It will execute 32-bit Java and c:\Windows\System32 points to the WOW64 folder, i.e. the 32-bit version of System32.

This answer shows how to check Java in the registry instead:

Need help on Inno Setup script - issue in check the jre install

Following that answer, the following code seems to work to check whether 64-bit Java 1.7+ is installed:

[Code]

function JavaIsMissing(): Boolean;
var 
javaVersionOutput: AnsiString;

begin

result := not RegQueryStringValue(HKLM64, 'Software\JavaSoft\Java Runtime Environment',
   'CurrentVersion', javaVersionOutput);
if not result then
   result := CompareStr(javaVersionOutput, '1.7') < 0;
end;

[Run]
Filename: "{tmp}\{#JavaInstaller}"; StatusMsg: "Java Runtime Enviroment not installed on your system. Installing..."; Check: JavaIsMissing

score 0 · Answer 2 · answered Dec 31 '20 at 17:36

I wanted something I could use across multiple Inno Setup projects, so I wrote a DLL for detecting Java details (home directory, etc.):

https://github.com/Bill-Stewart/JavaInfo

Download from here: https://github.com/Bill-Stewart/JavaInfo/releases

The download includes a sample Inno Setup .iss script that demonstrates how to use the DLL functions (including how to check whether 32-bit or 64-bit).

InnoSetup: Detect if Java is 32-bit or 64-bit

2 Answers2