Android Question Out of Memory (java.lang.AbstractStringBuilder.enlargeBuffer)

Sub ParseFile
   Dim In As InputStream = File.OpenInput(File.DirAssets, "filename.xml")
   Dim tr As TextReader
   tr.Initialize2(In, "ASCII")
   Dim buffer(1) As Char
   Dim sb As StringBuilder
   sb.Initialize
   Do Until sb.ToString.EndsWith("<GetReportResult>")
     tr.Read(buffer, 0, 1)
     sb.Append(buffer(0))
   Loop
   Dim base64File As OutputStream = File.OpenOutput(File.DirRootExternal, "1.base64", False)
   Dim tbase64File As TextWriter
   tbase64File.Initialize2(base64File, "ASCII")
   Dim count As Int
   Do While True
     tr.Read(buffer, 0, 1)
     If buffer(0) = "<" Then Exit
     tbase64File.Write(buffer(0))
     count = count + 1
     If count Mod 1000 = 0 Then Log(count)
   Loop
   tbase64File.Close
   Dim In As InputStream = File.OpenInput(File.DirRootExternal, "1.base64")
   Dim bis As JavaObject
   bis.InitializeNewInstance("android.util.Base64InputStream", Array(In, 0))
   Dim bb(8192) As Byte
   Dim out As OutputStream = File.OpenOutput(File.DirRootExternal, "1.pdf", False)
   Dim count As Int = bis.RunMethod("read", Array(bb, 0, bb.Length))
   Do While count > 0
     out.WriteBytes(bb, 0, count)
     Dim count As Int = bis.RunMethod("read", Array(bb, 0, bb.Length))
   Loop
   out.Close
End Sub