B4J Question SubString problem

[HARRY]

Hi,

I use the following code:

Sub AStream_NewData (Buffer() As Byte)
Dim s As String
Dim l As String
s= BytesToString(Buffer, 0, Buffer.Length, "UTF8")
Log(Buffer.Length)
Log(s)
l=s.SubString2(0,1)
Log(l)
If l=1 Then......

The Buffer.length is reported to be 32 as well as the s.length.

On l=s.SubString2(0,1) the program hangs a while and then announces: Error occurred on line 141 (main). This is the End Sub line of Sub AStream_NewData (Buffer() As Byte)

Debugging aborts


What am I doing wrong?

Harry

 

[Erel]

Please use [code]code here...[/code] tags when posting code.

Can you post the full error message from the logs?

 

[HARRY]

Sorry Erel,

Now the code as code and the log. May be that the first byte of the buffer and of s is not printable. i don't know whether that matters.

Sub AStream_NewData (Buffer() As Byte)
Dim b, s As String
Dim newhour As Int
Dim l As Char
Dim i As Int
    s= BytesToString(Buffer, 0, Buffer.Length, "UTF8")
    Log(Buffer.Length)
    Log (s.Length)
    Log(s)
    l=s.substring2(0,1)
    Log(l)

Program started.
(ArrayList) [/dev/ttyAMA0, /dev/ttyUSB0]
0
0
Error occurred on line: 77 (main).
java.lang.StringIndexOutOfBoundsException: String index out of range: 1
at java.lang.String.substring(String.java:1950)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at anywheresoftware.b4a.shell.Shell.runMethod(Shell.java:563)
at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:221)
at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:156)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at anywheresoftware.b4a.BA.raiseEvent2(BA.java:93)
at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:82)
at anywheresoft
ware.b4a.BA$3.run(BA.java:178)
at anywheresoftware.b4a.keywords.SimpleMessageLoop.runMessageLoop(SimpleMessageLoop.java:30)
at anywheresoftware.b4a.StandardBA.startMessageLoop(StandardBA.java:26)
at anywheresoftware.b4a.ShellBA.startMessageLoop(ShellBA.java:103)
at anywheresoftware.b4a.keywords.Common.StartMessageLoop(Common.java:131)
at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:292)
at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:156)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at anywheresoftware.b4a.BA.raiseEvent2(BA.java:93)
at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:82)
at anywheresoftware.b4a.BA.raiseEvent(BA.java:84)
at b4j.example.main.main(main.java:29)

 

[Erel]

You can see from the logs that the string is empty. Why are you converting the data to a string? What is the source of this data?
Only text data should be converted to string.

 

[HARRY]

Sorry again,

The source of the data is a mixture of words and a structure containing integers, Strings and bytes. Decoding it is too difficult for me. Meanwhile I have changed the set up. The source now is just a String and I am going to use AsyncStreamsText, avoiding a lot of pitfalls.

Harry