| org.xml.sax.EntityResolver
All known Subclasses: org.xml.sax.HandlerBase,
| EntityResolver | | public interface EntityResolver (Code) | | Basic interface for resolving entities.
If a SAX application needs to implement customized handling
for external entities, it must implement this interface and
register an instance with the SAX parser using the parser's
setEntityResolver method.
The parser will then allow the application to intercept any
external entities (including the external DTD subset and external
parameter entities, if any) before including them.
Many SAX applications will not need to implement this interface,
but it will be especially useful for applications that build
XML documents from databases or other specialised input sources,
or for applications that use URI types other than URLs.
The following resolver would provide the application
with a special character stream for the entity with the system
identifier "http://www.myhost.com/today":
import org.xml.sax.EntityResolver;
import org.xml.sax.InputSource;
public class MyResolver implements EntityResolver {
public InputSource resolveEntity (String publicId, String systemId)
{
if (systemId.equals("http://www.myhost.com/today")) {
// return a special input source
MyReader reader = new MyReader();
return new InputSource(reader);
} else {
// use the default behaviour
return null;
}
}
}
The application can also use this interface to redirect system
identifiers to local URIs or to look up replacements in a catalog
(possibly by using the public identifier).
The HandlerBase class implements the default behaviour for
this interface, which is simply always to return null (to request
that the parser use the default system identifier).
author:
David Megginson (ak117@freenet.carleton.ca)
version:
1.0
See Also: org.xml.sax.Parser.setEntityResolver
See Also: org.xml.sax.InputSource
See Also: org.xml.sax.HandlerBase
See Also: |
| Method Summary | |
| abstract public InputSource | resolveEntity(String publicId, String systemId)
Allow the application to resolve external entities.
The Parser will call this method before opening any external
entity except the top-level document entity (including the
external DTD subset, external entities referenced within the
DTD, and external entities referenced within the document
element): the application may request that the parser resolve
the entity itself, that it use an alternative URI, or that it
use an entirely different input source.
Application writers can use this method to redirect external
system identifiers to secure and/or local URIs, to look up
public identifiers in a catalogue, or to read an entity from a
database or other input source (including, for example, a dialog
box).
If the system identifier is a URL, the SAX parser must
resolve it fully before reporting it to the application.
Parameters:
publicId - The public identifier of the external entitybeing referenced, or null if none was supplied.
Parameters:
systemId - The system identifier of the external entitybeing referenced. |
| resolveEntity | | abstract public InputSource resolveEntity(String publicId, String systemId) throws SAXException, IOException(Code) | | Allow the application to resolve external entities.
The Parser will call this method before opening any external
entity except the top-level document entity (including the
external DTD subset, external entities referenced within the
DTD, and external entities referenced within the document
element): the application may request that the parser resolve
the entity itself, that it use an alternative URI, or that it
use an entirely different input source.
Application writers can use this method to redirect external
system identifiers to secure and/or local URIs, to look up
public identifiers in a catalogue, or to read an entity from a
database or other input source (including, for example, a dialog
box).
If the system identifier is a URL, the SAX parser must
resolve it fully before reporting it to the application.
Parameters:
publicId - The public identifier of the external entitybeing referenced, or null if none was supplied.
Parameters:
systemId - The system identifier of the external entitybeing referenced. An InputSource object describing the new input source,or null to request that the parser open a regularURI connection to the system identifier.
exception:
org.xml.sax.SAXException - Any SAX exception, possiblywrapping another exception.
exception:
java.io.IOException - A Java-specific IO exception,possibly the result of creating a new InputStreamor Reader for the InputSource.
See Also: org.xml.sax.InputSource |
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