B4J currently supports two types of applications: UI applications (based on JavaFX) and Non-UI applications.
Non-UI applications are standard Java applications. Usually the input to such applications is with command line arguments.
You should create a new project and select:
The program starts with:
The program will end after this sub unless you call StartMessageLoop. Calling StartMessageLoop means that the main thread is now handling an internal message queue. This is useful if you need to wait for some other event to happen.
For example, we will create a very simple "curl" application. curl is a Linux app that allows you to send Http requests.
In this case the program will receive one argument which is the URL, it will download it and print the downloaded resource.
In order to test it we need to provide the command line argument. This is done with the #CommandLineArgs module attribute.
The complete code:
The jar file created is not an executable jar. You need to run it by calling the java program.
The syntax is:
You can create a batch file or script to run it.
Note that instead of referencing jHttpUtils2, we are using its source code. jHttpUtils2 library depends on jFX (for the GetBitmap method which is removed here).
Non-UI applications are standard Java applications. Usually the input to such applications is with command line arguments.
You should create a new project and select:
The program starts with:
B4X:
Sub AppStart(Args() As String)
End SubThe program will end after this sub unless you call StartMessageLoop. Calling StartMessageLoop means that the main thread is now handling an internal message queue. This is useful if you need to wait for some other event to happen.
For example, we will create a very simple "curl" application. curl is a Linux app that allows you to send Http requests.
In this case the program will receive one argument which is the URL, it will download it and print the downloaded resource.
In order to test it we need to provide the command line argument. This is done with the #CommandLineArgs module attribute.
The complete code:
B4X:
'Non-UI application (console application)
#Region Project Attributes
#CommandLineArgs: http://www.b4x.com
#End Region
Sub Process_Globals
End Sub
Sub AppStart (Args() As String)
If Args.Length = 0 Then
Log("URL is missing.")
ExitApplication2(1)
End If
Dim j As HttpJob
j.Initialize("j", Me)
j.Download(Args(0))
StartMessageLoop
End Sub
Sub JobDone(Job As HttpJob)
If Job.Success Then
Log(Job.GetString)
Else
Log(Job.ErrorMessage)
End If
Job.Release
ExitApplication2(0) 'exit the application. Without this call the program will just hang.
End SubThe jar file created is not an executable jar. You need to run it by calling the java program.
The syntax is:
B4X:
java -cp <jar file> <package>.main <args>Note that instead of referencing jHttpUtils2, we are using its source code. jHttpUtils2 library depends on jFX (for the GetBitmap method which is removed here).
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