Inno Setup - Setting Java Environment Variable

Question

I am using Inno Setup to make an installer for a project I am working on, and I need it to set the java environment variable, so that when they run cmd they don\'t get a

Answer 1

Adding up to @Joni's answer, you can get the Java installation directory from the registry and use script constants to set your environment variable:

(EDIT: thanks to @TLama for code correction!)

[Registry]
Root: HKCU; Subkey: "Environment"; ValueType:string; ValueName:"JAVA_HOME"; ValueData:"{code:GetJava32Path|6}"; Flags: preservestringtype

[Code]
const
  RegKeyJRE = 'SOFTWARE\JavaSoft\Java Runtime Environment\';

function GetJava32Path(MinVersion: string): string;
var
  I: Integer;
  Path: string;
  Versions: TArrayOfString;
begin
  Result := '';
  if RegGetSubkeyNames(HKLM, RegKeyJRE, Versions) then
    for I := 0 to GetArrayLength(Versions)-1 do
      if (Versions[I][2] = '.') and (Versions[I][3] >= MinVersion) and
        RegQueryStringValue(HKLM32, RegKeyJRE + Versions[I], 'JavaHome', Path) then
      begin
        Result := Path;
        Exit;
      end;
end;

(N.B. I'm far from being a Pascal-script expert, the code could be a lot better, though now it was corrected by @TLama :))