java - how to find in xsd, whether the particular tag is available in xml or not? -

my xml file is,

 <?xml version="1.0"?>  <type xmlns:xs="http://www.w3.org/2001/xmlschema-instance"                                               xs:nonamespaceschemalocation="datatype.xsd">      <int>integer</int>     <varchar>varcharacter</varchar>     <double>doubles</double>     </type> 

in xml, want set <float></float> mandatory. didn't use tag. how validate <float> present or not in xml file, using xsd java.? in advance.

the following can used validate xml against schema:

import java.io.file;  import javax.xml.xmlconstants; import javax.xml.validation.schema; import javax.xml.validation.schemafactory; import javax.xml.validation.validator;  public class demo {      public static void main(string[] args) throws exception {         schemafactory sf = schemafactory.newinstance(xmlconstants.w3c_xml_schema_ns_uri);         schema schema = sf.newschema(new file("datatype.xsd"));          validator validator = schema.newvalidator();         validator.seterrorhandler(new myerrorhandler());         validator.validate(source);     }  } 

for more detailed example see:

• http://bdoughan.blogspot.com/2010/11/validate-jaxb-object-model-with-xml.html