Having trouble understanding XML DTD. Getting getting root element not well formed error when I parse

Question

I'm new to XML. I'm working on an assignment and I'm stuck on external DTD validation. I get an error when I parse the file that says root element is not well formed. Both files are in the same directory.

Here is the external DTD:

   <!DOCTYPE atoms [
   <!ELEMENT atoms (hydrogen, carbon, oxygen, titanium, uranium)>
   <!ATTLIST atoms properties CDATA #REQUIRED>
   <!ELEMENT hydrogen (#PCDATA)>
   <!ELEMENT carbon (#PCDATA)>
   <!ELEMENT oxygen (#PCDATA)>
   <!ELEMENT titanium (#PCDATA)>
   <!ELEMENT uranium (#PCDATA)> 
   <!ATTLIST properties symbol CDATA #REQUIRED>
   <!ATTLIST properties name CDATA #REQUIRED>
   <!ATTLIST properties atomicNumber CDATA #REQUIRED>
   <!ATTLIST properties atomicWeight CDATA #REQUIRED>
   ]>

Here is my XML file:

<?xml version="1.0" encoding="UTF-8"?>
<!--DTD is in a local directory file named atoms.dtd -->
<!-- Week 3 Homework -->
<!DOCTYPE atoms SYSTEM "atoms.dtd">    
  <atoms>
    <hydrogen>   
        <properties symbol="H" name="Hydrogen" atomicNumber="1" atomicWeight="1.00794"/>
    </hydrogen>

    <carbon>   
        <properties symbol="C" name="Carbon" atomicNumber="6" atomicWeight="12.011"/>
    </carbon>

    <oxygen>   
        <properties symbol="O" name="Oxygen" atomicNumber="8" atomicWeight="15.999"/>
    </oxygen>

    <titanium>   
        <properties symbol="Ti" name="Titanium" atomicNumber="22" atomicWeight="47.867"/>
    </titanium>

    <uranium>   
        <properties symbol="U" name="Uranium" atomicNumber="92" atomicWeight="238.03"/>
    </uranium>
  </atoms>

Edit:

I tried it this way just now and I'm still getting errors when I parse.

External DTD:

    <!DOCTYPE atoms [ <!ELEMENT atoms (atom+)>  
    <!ELEMENT atom (symbol, name, atomicNumber, atomicWeight)>
    <!ELEMENT symbol (#PCDATA)>
    <!ELEMENT name (#PCDATA)>
    <!ELEMENT atomicNumber (#PCDATA)>
    <!ELEMENT atomicWeight (#PCDATA)> ]>

XML:

    <?xml version="1.0" encoding="UTF-8"?>
    <!--DTD is in a local directory file named atomsV2.dtd -->
    <!-- Week 3 Homework -->
    <!DOCTYPE atoms SYSTEM "atomsV2.dtd"> 
        <atoms>
            <atom> 
                <symbol H />
                <name Hydrogen />
                <atomicNumber 1 />
                <atomicWeight 1.00794 />
           </atom>

            <atom>   
                <symbol C />
                <name Carbon />
                <atomicNumber 6 />
                <atomicWeight 12.011 />
            </atom>

            <atom>   
                <symbol O />
                <name Oxygen />
                <atomicNumber 8 />
                <atomicWeight 15.999 />
            </atom>

            <atom>   
                <symbol Ti />
                <name Titanium />
                <atomicNumber 22 />
                <atomicWeight 47.867 />
            </atom>

            <atom>   
                <symbol U />
                <name Uranium />
                <atomicNumber 92 />
                <atomicWeight 238.03 />
            </atom>
         </atoms>

possible duplicate of [Problem with external referenced DTD in XML](http://stackoverflow.com/questions/5455394/problem-with-external-referenced-dtd-in-xml) — Daniel Haley, Jul 11 '14 at 15:40

score 0 · Answer 1 · edited May 23 '17 at 12:11

Here's a version that works. Your question is showing 2 different XML/DTD pairs with totally different structure, so if this isn't the answer you're looking for, please update your question.

Also, see External referenced DTD in XML for a better explanation of why what you were doing wasn't working.

External DTD

<!ELEMENT atoms (hydrogen, carbon, oxygen, titanium, uranium)>
<!ATTLIST atoms properties CDATA #IMPLIED>
<!ELEMENT hydrogen (properties)>
<!ELEMENT carbon (properties)>
<!ELEMENT oxygen (properties)>
<!ELEMENT titanium (properties)>
<!ELEMENT uranium (properties)>
<!ELEMENT properties EMPTY>
<!ATTLIST properties 
    symbol CDATA #REQUIRED
    name CDATA #REQUIRED
    atomicNumber CDATA #REQUIRED
    atomicWeight CDATA #REQUIRED>

XML

<!DOCTYPE atoms SYSTEM "atoms.dtd">
<atoms>
    <hydrogen>   
        <properties symbol="H" name="Hydrogen" atomicNumber="1" atomicWeight="1.00794"/>
    </hydrogen>

    <carbon>   
        <properties symbol="C" name="Carbon" atomicNumber="6" atomicWeight="12.011"/>
    </carbon>

    <oxygen>   
        <properties symbol="O" name="Oxygen" atomicNumber="8" atomicWeight="15.999"/>
    </oxygen>

    <titanium>   
        <properties symbol="Ti" name="Titanium" atomicNumber="22" atomicWeight="47.867"/>
    </titanium>

    <uranium>   
        <properties symbol="U" name="Uranium" atomicNumber="92" atomicWeight="238.03"/>
    </uranium>
</atoms>

Having trouble understanding XML DTD. Getting getting root element not well formed error when I parse

1 Answers1