B4J Library [tool] Compile project with different version of Java

Don't use this. Starting from B4J v8.80 there is a built-in option (#JavaCompilerPath): https://www.b4x.com/android/forum/threads/b4j-v8-80-has-been-released-🍾.125536/#content


1. Download the attached jar and put it in B4J internal folder. Not in the libraries folder.

2. Add these comments to your project:

'Compile with Java 8:  ide://run?file=%B4X%\ProjectCompiler.jar&VMArgs=-Db4x%3D%B4X%&Args=-Task%3DBuild&Args=-BaseFolder%3D..&VMArgs=-Djavabin%3DC:\Program+Files\Java\jdk1.8.0_211\bin
'Compile with Java 14: ide://run?file=%B4X%\ProjectCompiler.jar&VMArgs=-Db4x%3D%B4X%&Args=-Task%3DBuild&Args=-BaseFolder%3D..&VMArgs=-Djavabin%3DC:\jdk-14.0.1\bin

3. Change the last parameter based on your java path. Note that you need to replace spaces with + and (, ) with %28 and %29.
4. Ctrl + click on the links to compile.

 

[Erel]

Source code of this utility:

Sub AppStart (Args() As String)
    Log("Project Compiler v1.00")
    Dim inifolder As String = File.Combine(File.DirData("Anywhere Software"), "B4J")
    If File.Exists(inifolder, "b4xV5.ini") = False Then
        Log("Can't find B4J ini file.")
        ExitApplication2(1)
    End If
    Dim javabin As String = GetSystemProperty("javabin", "")
    Log($"javabin: ${javabin}"$)
    If File.Exists(javabin, "javac.exe") = False Then
        Log("Can't find javac.exe")
        ExitApplication2(1)
    End If
    File.Copy(inifolder, "b4xV5.ini", inifolder, "inibackup.bak")
    Dim ini As List = File.ReadList(inifolder, "b4xV5.ini")
    For i = 0 To ini.Size - 1
        Dim line As String = ini.Get(i)
        If line.StartsWith("JavaBin") Then
            ini.Set(i, $"JavaBin=${javabin}"$)
        End If
    Next
    File.WriteList(inifolder, "b4xV5.ini", ini)
    Try
        Dim builder As String = File.Combine(GetSystemProperty("b4x", ""), "B4JBuilder.exe")
        Dim shl As Shell
        shl.Initialize("", builder, Args)
        Dim res As ShellSyncResult = shl.RunSynchronous(60000)
        Log($"Exit code: ${res.ExitCode}
StdOut: ${res.StdOut}
StdErr: ${res.StdErr}
"$)
    Catch
        Log(LastException)
    End Try
    File.Copy(inifolder, "inibackup.bak", inifolder, "b4xV5.ini")
End Sub

 

[Greg Breinholt]

Is there a reason/pro/con to choose Java 14 over 8?

 

[Erel]

This is not the correct place for this question.

 

[Tobias Leininger]

That's pretty useful!

Do you think compiling to different Java versions will be added to the IDE in the future?

 

[Erel]

No. The solution above is perfect for the few cases where it is needed.
It is more flexible than any built-in feature.

What are you missing?

 

[Tobias Leininger]

Different compiler heap sizes, full error messages, integration with B4X-Bridge.
But then I'll add those things myself or keep changing the SDK path.

 

[Erel]

The full error message will be in the logs.

Different compiler heap sizes

Why??? Never encountered a case where it needs to be changed.
How can you do it with changing the SDK path?

Integrating with B4J-Bridge will be much more complicated.

 

[Tobias Leininger]

The full error message will be in the logs.


Why??? Never encountered a case where it needs to be changed.
How can you do it with changing the SDK path?

Integrating with B4J-Bridge will be much more complicated.

Old Java 8 doesn't like very large compiler heap sizes on my machine, while newer ones do. And for some projects I need larger values.

Right now I just have a batch file doing changes to the ini file to switch between different versions.