NSIS script for java installation

Question

I want to install Java using an NSIS script, but i have to know whether Java is installed or not in the system (Windows). based on the register keys how can we check if Java

Answer 1

I didn't compile it, but I would try following. I chose registry key based on How can I detect the installed Sun JRE on Windows?.

;--------------------------------
;Defines

  !define JavaRegKey 'HKLM "Software\JavaSoft\Java Runtime Environment" ""'

;--------------------------------
;Installer Sections
Section 'Java Runtime' SecJava

  SetOutPath '$TEMP'
  SetOverwrite on
  File 'c:\\javasetup.exe'
  ExecWait '$TEMP\javasetup.exe' $0
  DetailPrint '..Java Runtime Setup exit code = $0'
  Delete '$TEMP\javasetup.exe'

SectionEnd

;--------------------------------
;   Functions
Function .onInit

  ReadRegStr $R0 ${JavaRegKey}
  StrCmp $R0 "" JavaMissing JavaFound

  JavaFound: 
  !insertmacro UnselectSection ${SecJava}
  Goto JavaCheckDone

  JavaMissing:
  !insertmacro SelectSection ${SecJava}

  JavaCheckDone:

FunctionEnd