[TAPESTRY-2758] For very complex forms, encoding the allocated ID string results in a java.io.UTFDataFormatException

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 4.1.6
• Component/s: Framework
• Assignee: Unassigned
• Reporter: Howard Lewis Ship
• Created: 29/Dec/09 18:12
• Updated: 29/Dec/09 18:12

Description

• java.io.UTFDataFormatException
  java.io.ObjectOutputStream$BlockDataOutputStream#writeUTF (ObjectOutputStream.java:2125)
  java.io.ObjectOutputStream$BlockDataOutputStream#writeUTF (ObjectOutputStream.java:1968)
  java.io.ObjectOutputStream#writeUTF (ObjectOutputStream.java:841)
  org.apache.tapestry.util.io.CompressedDataEncoder#encodeString (CompressedDataEncoder.java:55)
  org.apache.tapestry.engine.RequestCycle#encodeIdState (RequestCycle.java:678)
  org.apache.tapestry.form.FormSupportImpl#render (FormSupportImpl.java:482)
  org.apache.tapestry.form.Form#renderComponent (Form.java:217)

A little digging found out that this can only happen for exceptionally large forms. The relevent code:

RequestCycle.java:

public String encodeIdState()

{ return CompressedDataEncoder.encodeString(_idAllocator.toExternalString()); }

CompressedDataEncoder.java:

public static String encodeString(String input)
{
Defense.notNull(input, "input");

if (HiveMind.isBlank(input))
return "";

try

{ ByteArrayOutputStream bosPlain = new ByteArrayOutputStream(); ByteArrayOutputStream bosCompressed = new ByteArrayOutputStream(); GZIPOutputStream gos = new GZIPOutputStream(bosCompressed); TeeOutputStream tos = new TeeOutputStream(bosPlain, gos); ObjectOutputStream oos = new ObjectOutputStream(new BufferedOutputStream(tos)); oos.writeUTF(input); oos.close(); boolean useCompressed = bosCompressed.size() < bosPlain.size(); byte[] data = useCompressed ? bosCompressed.toByteArray() : bosPlain.toByteArray(); byte[] encoded = Base64.encodeBase64(data); String prefix = useCompressed ? GZIP_BYTESTREAM_PREFIX : BYTESTREAM_PREFIX; return prefix + new String(encoded); }

catch (Exception ex)

{ throw new ApplicationRuntimeException(IoMessages.encodeFailure(input, ex), ex); }

}

ObjectOutputStream.java:

void writeUTF(String s, long utflen) throws IOException {
if (utflen > 0xFFFFL)

{ throw new UTFDataFormatException(); }

writeShort((int) utflen);
if (utflen == (long) s.length())

{ writeBytes(s); }

else

{ writeUTFBody(s); }

}

So for strings larger than 65K, we get the exception. Yes, that's an incredibly large form!