Question

I’m working on a game launcher (Yes there is already one, but mine will be different).
The problem is, if you log in, the game tries to launch, but I get a console window displaying “cannot access jarfile c:\users\max korlaar\dropbox\max ” and it closes after 1 milisecond.
I don’t know why, because the given jar files in my Process Arguments are there, and I think VB.net does something with the location. The jar files are located in a folder Bin, relative to my program. (And Yes, I tried replacing + with &)

Dim process As New Process
Dim info As New ProcessStartInfo
info.FileName = GetJavaHome() + "\java.exe"
info.CreateNoWindow = True
info.UseShellExecute = True
info.RedirectStandardError = False
info.RedirectStandardOutput = False
Dim args As String = "-jar  -natives{1} -lwjgl{2} -mlcfg{3} -mlmod{4} -j{5} -u{6} -s{7}"
info.Arguments = String.Format(args, My.Application.Info.DirectoryPath + "\bin\natives", My.Application.Info.DirectoryPath + "\bin\natives", My.Application.Info.DirectoryPath + "\bin\lwjgl.jar", My.Application.Info.DirectoryPath + "\config\", My.Application.Info.DirectoryPath + "\mods\", My.Application.Info.DirectoryPath + "\bin\minecraft.jar\", TextBox1.Text, result)
info.Arguments = info.Arguments.Replace("\bin\minecraft.jar", My.Application.Info.DirectoryPath + "\bin\minecraft.jar")
process.StartInfo = info
process.Start()

After trying some suggestions I modified it a little, and got this:

    Dim process As New Process
    Dim info As New ProcessStartInfo
    info.FileName = GetJavaHome() + "\java.exe"
    info.CreateNoWindow = False
    info.UseShellExecute = False
    info.RedirectStandardError = False
    info.RedirectStandardOutput = True

    'Got error: Corrupt jar file... Someone with Minecraft Experience can help me to launch it?
    Dim args As String = "-jar ""{6}"" -natives ""{1}"" -lwjgl ""{2}"" -mlcfg ""{3}"" -mlmod ""{4}"" -j ""{5}"" -u ""{6}"" -s ""{7}"""
    ' Got CMD window popping up with error and disappearing
    info.Arguments = String.Format(args, "none", My.Application.Info.DirectoryPath & "\bin\natives\", My.Application.Info.DirectoryPath & "\bin\natives", My.Application.Info.DirectoryPath & "\bin\lwjgl.jar", My.Application.Info.DirectoryPath & "\config\", My.Application.Info.DirectoryPath & "\mods\", "'" & Application.StartupPath & "\bin\minecraft.jar'", TextBox1.Text, result)
    'info.Arguments = info.Arguments.Replace("\bin\minecraft.jar", My.Application.Info.DirectoryPath + "\bin\minecraft.jar")
    process.StartInfo = info
    process.Start()

But now I get the error: Unable to access jarfile “{path to minecraft.jar (correct path)}”
Does anyone know why? And how to fix that error?

Answer 1

You have a space in your paths, so you have to quote it (put in between two ").

Dim args As String = "-jar  -natives""{1}"" -lwjgl""{2}"" ...etc..etc..."

Otherwise, the java executable will not be able to distinguish correctly between the arguments you pass to it.

---

If your path is c:\users\max korlaar\dropbox\max & alex, and you don’t quote it, you pass it to the java executale as

java -jar c:\users\max korlaar\dropbox\max & alex

where only c:\users\max korlaar\dropbox\max would be used as an argument to to java -jar.

Hence you have to use quotes:

java -jar “c:\users\max korlaar\dropbox\max & alex”