One of my customers has found out that the DTD published by Sun to validate property files in JSE 1.5.0 is not well formed!

The javadoc explains :

Note that the system URI (http://java.sun.com/dtd/properties.dtd) is not accessed when exporting or importing properties; it merely serves as a string to uniquely identify the DTD, which is:

<?xml version="1.0" encoding="UTF-8"?>

<!-- DTD for properties -->

<!ELEMENT properties ( comment?, entry* ) >

<!ATTLIST properties version CDATA #FIXED "1.0">

<!ELEMENT comment (#PCDATA) >

<!ELEMENT entry (#PCDATA) >

<!ATTLIST entry key CDATA #REQUIRED>

Reducing the system URI to a mere identifier is a simplification that can lead to problems when you parse your document: XML parsers are free to load DTDs even if you specify standalone=”yes” in your XML declaration and even if you run them in non-validating mode.

In that case, including a system URI pointing to a non well formed DTD means that depending on you parser and on the options you’ll send it at parse time, you may get (or not) a well formness error.

Interestingly, the DTD listed above and borrowed from the javadoc is well formed.

The DTD published at http://java.sun.com/dtd/properties.dtd appears to have been modified to:

<!--
   Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
  -->

<?xml version="1.0" encoding="UTF-8"?>

<!-- DTD for properties -->

<!ELEMENT properties ( comment?, entry* ) >

<!ATTLIST properties version CDATA #FIXED "1.0">

<!ELEMENT comment (#PCDATA) >

<!ELEMENT entry (#PCDATA) >

<!ATTLIST entry key CDATA #REQUIRED>

See what has happened? Someone has probably insisted that they should add a copyright statement at the beginning of each of their documents, forgetting that XML forbids comments before the XML declaration…

We shouldn’t let lawyers edit XML documents!