javax.xml.stream.DTDStreamReader Maven / Gradle / Ivy
/*
* Portions Copyright 2000-2008 Sun Microsystems, Inc. All Rights
* Reserved. Use is subject to license terms.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 only, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License version 2 for more details (a copy is
* included at /legal/license.txt).
*
* You should have received a copy of the GNU General Public License
* version 2 along with this work; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
* Clara, CA 95054 or visit www.sun.com if you need additional
* information or have any questions.
*/
package javax.xml.stream;
import java.util.NoSuchElementException;
import javax.xml.stream.XMLStreamConstants;
import javax.xml.stream.XMLStreamReader;
import javax.xml.stream.Location;
import javax.xml.stream.XMLStreamException;
/**
* This interface extends the Streaming API for XML (StAX) Cursor API.
* It enables forward, read-only access to
* general internal and external parsed and unparsed entity declarations,
* notation declarations, processing instructions and comments contained in
* a DTD.
*
* The DTDStreamReader instance has very specific lifecycle constraints.
* An application can only obtain an implementation of DTDStreamReader from
* {@link XMLStreamReader XMLStreamReader} immediately after the method
* {@link XMLStreamReader#next() next()} returns a
* {@link XMLStreamReader#DTD DTD} event, and prior to invoking any other
* methods on {@link XMLStreamReader XMLStreamReader}. The
* DTDStreamReader instance is obtained by calling method
* {@link XMLStreamReader#getProperty getProperty} with
* "javax.xml.stream.DTDStreamReader" as the property name
* parameter.
* Multiple calls to {@link XMLStreamReader#getProperty getProperty} with
* a "javax.xml.stream.DTDStreamReader" argument will return the
* same instance of DTDStreamReader.
* Once the DTDStreamReader object is instantiated by the
* application, its various methods can be used to access the DTD data. Its
* processing capability extends only until the {@link #END_DTD END_DTD} event
* is reached;
* at this point, any further document processing must be performed via the
* {@link XMLStreamReader XMLStreamReader} instance.
*
*
* If an application chooses to instantiate a DTDStreamReader,
* the {@link XMLStreamReader#getText() getText()} method on
* {@link XMLStreamReader XMLStreamReader} is invalidated
* for the {@link XMLStreamReader#DTD DTD} event: any attempt to invoke
* it will generate a java.lang.IllegalStateException. In this case,
* the data for the DTD event must be obtained via the DTDStreamReader
* instance.
*
*
* After DTDStreamReader is instantiated, invocation of any of
* the following {@link XMLStreamReader XMLStreamReader} methods
* will change the state of
* DTDStreamReader implementation to {@link #END_DTD END_DTD}:
*
- {@link XMLStreamReader#next() next()},
* - {@link XMLStreamReader#hasNext() hasNext()},
* - {@link XMLStreamReader#nextTag() nextTag()} and
* - {@link XMLStreamReader#close() close()}.
* Once in the {@link #END_DTD END_DTD} state,
* no further processing of the DTD data is possible.
*
*
* If no instance of DTDStreamReader is created (either the
* {@link XMLStreamReader#getProperty getProperty} method with parameter
* "javax.xml.stream.DTDStreamReader" is never invoked,
* or it returns null because it is not invoked
* immediately after a {@link XMLStreamReader#DTD DTD} event is received),
* the behavior of
* {@link XMLStreamReader XMLStreamReader} is unchanged and follows the
* specification in
* JSR173
* for the JSR 280 subset of the API.
*
*
* DTDStreamReader intentionally mimics
* {@link XMLStreamReader XMLStreamReader} in order to provide developers
* with a familiar programming model.
* DTDStreamReader includes several methods identical in signature
* and semantics to methods defined on {@link XMLStreamReader XMLStreamReader}.
*
* An object which implements DTDStreamReader uses methods {@link #next next}
* and {@link #getEventType getEventType} to provide the current event type.
* The first event is always {@link #START_DTD START_DTD}.
* Once an {@link #END_DTD END_DTD} event is returned by methods
* {@link #next next} or {@link #getEventType getEventType}, the application
* must continue further document processing using the
* {@link XMLStreamReader XMLStreamReader} interface.
* The application can use the {@link #close close} method at any time to
* terminate processing of any remaining DTD content and skip to the
* {@link #END_DTD END_DTD} event.
*
* The following table describes which methods are valid in what state.
* If a method is called in an invalid state the method will throw a
* java.lang.IllegalStateException. Method {@link #next() next()} is an
* exception from this rule: it is defined to throw
* NoSuchElementException if it is called when {@link #hasNext() hasNext()}
* returns false, so in the case where {@link #next() next()}
* is called in the END_DTD state it will return NoSuchElementException rather
* than java.lang.IllegalStateException.
*
*
*
*
* Valid methods for each state
*
*
*
* Event Type
* Valid Methods
*
*
* All States
* {@link #hasNext() hasNext},
* {@link #getEventType() getEventType},
* {@link #getLocation() getLocation},
* {@link #close() close}
*
*
*
* {@link #START_DTD START_DTD}
* {@link #next() next},
* {@link #getName() getName},
* {@link #getPublicIdentifier() getPublicIdentifier},
* {@link #getSystemIdentifier() getSystemIdentifier}
*
*
*
* {@link #END_DTD END_DTD}
*
*
* {@link #ENTITY_DECLARATION ENTITY_DECLARATION}
* {@link #next() next},
* {@link #getName() getName},
* {@link #getPublicIdentifier() getPublicIdentifier},
* {@link #getSystemIdentifier() getSystemIdentifier}
* {@link #getText() getText},
* {@link #getTextCharacters getTextCharacters},
* {@link #getTextStart() getTextStart},
* {@link #getTextLength() getTextLength}
*
*
* {@link #UNPARSED_ENTITY_DECLARATION UNPARSED_ENTITY_DECLARATION}
* {@link #next() next},
* {@link #getName() getName},
* {@link #getPublicIdentifier() getPublicIdentifier},
* {@link #getSystemIdentifier() getSystemIdentifier},
* {@link #getNotationName() getNotationName}
*
*
* {@link #NOTATION_DECLARATION NOTATION_DECLARATION}
* {@link #next() next},
* {@link #getName() getName},
* {@link #getPublicIdentifier() getPublicIdentifier},
* {@link #getSystemIdentifier() getSystemIdentifier}
*
*
*
* {@link #COMMENT COMMENT}
* {@link #next() next},
* {@link #getText() getText},
* {@link #getTextCharacters getTextCharacters},
* {@link #getTextStart() getTextStart},
* {@link #getTextLength() getTextLength}
*
*
*
* {@link #PROCESSING_INSTRUCTION PROCESSING_INSTRUCTION}
* {@link #next() next},
* {@link #getPITarget() getPITarget},
* {@link #getPIData() getPIData}
*
*
*
*
* @version 1.0
* @author Copyright (c) 2006 by BEA Systems. All Rights Reserved.
* @see XMLStreamConstants
* @see XMLStreamReader
*/
public interface DTDStreamReader
{
/**
* Indicates an event is the start of a DTD. On this event, method
* {@link #getName() getName} returns the root element's
* qualified name, and methods
* {@link #getPublicIdentifier() getPublicIdentifier} and
* {@link #getSystemIdentifier() getSystemIdentifier} return the document's
* public and system identifiers.
*/
public static final int START_DTD = 1001;
/**
* Indicates an event is the end of a DTD. On this event, method
* {@link #hasNext() hasNext} returns false,
* and method {@link #getEventType() getEventType} returns
* {@link #END_DTD END_DTD}. This event marks the end of the valid
* lifecycle of the DTDStreamReader instance, so any
* method call other than {@link #next() next}, {@link #hasNext() hasNext},
* {@link #getEventType() getEventType}, {@link #close() close},
* or {@link #getLocation() getLocation} on this interface will
* throw java.lang.IllegalStateException.
*/
public static final int END_DTD = 1002;
/**
* Indicates an event is a parsed entity declaration.
*
* If
* the {@link #getTextLength getTextLength} method returns a negative
* value, the event represents an external parsed entity:
* method {@link #getName() getName} returns the
* entity name, methods {@link #getPublicIdentifier getPublicIdentifier}
* and {@link #getSystemIdentifier getSystemIdentifier} return the
* entity's public and system identifiers, and methods
* {@link #getText getText} and {@link #getTextCharacters getTextCharacters}
* return null and empty array, respectively.
*
* If the {@link #getTextLength getTextLength} method returns a positive
* value, then the event represents an internal parsed entity:
* method {@link #getName() getName} returns the
* entity name, methods {@link #getText getText} or
* {@link #getTextCharacters getTextCharacters} return the replacement
* text of an internal parsed entity, and methods
* {@link #getPublicIdentifier getPublicIdentifier} and
* {@link #getSystemIdentifier getSystemIdentifier} return null.
*/
public static final int ENTITY_DECLARATION =
XMLStreamConstants.ENTITY_DECLARATION;
/**
* Indicates an event is an unparsed entity declaration. On this event,
* method {@link #getName() getName} returns the unparsed
* entity name, methods {@link #getPublicIdentifier getPublicIdentifier}
* and {@link #getSystemIdentifier getSystemIdentifier} return
* the public identifier and the system identifier of an unparsed entity,
* and the
* method {@link #getNotationName() getNotationName} returns the name of
* the notation which identifies the format of the unparsed entity.
*/
public static final int UNPARSED_ENTITY_DECLARATION = 1003;
/**
* Indicates an event is a notation declaration. On this event the method
* {@link #getName() getName} returns the notation name,
* the methods {@link #getPublicIdentifier getPublicIdentifier}
* and {@link #getSystemIdentifier getSystemIdentifier} return the
* public identifier and the system identifier of the notation.
*/
public static final int NOTATION_DECLARATION =
XMLStreamConstants.NOTATION_DECLARATION;
/**
* Indicates an event is a processing instruction. On this event,
* the method
* {@link #getPITarget() getPITarget} returns the processing instruction
* target and the method {@link #getPIData() getPIData} returns the
* processing instruction data section.
*/
public static final int PROCESSING_INSTRUCTION =
XMLStreamConstants.PROCESSING_INSTRUCTION;
/**
* Indicates an event is a comment. On this event, the methods
* {@link #getText() getText} or
* {@link #getTextCharacters getTextCharacters} return the character
* data of the comment, and
* the methods {@link #getTextStart() getTextStart} and
* {@link #getTextLength() getTextLength} return the index of the
* first character
* and the number of characters in the character array returned by
* the {@link #getTextCharacters getTextCharacters} method.
*/
public static final int COMMENT =
XMLStreamConstants.COMMENT;
/**
* Returns next DTD parsing event.
*
* @return the integer code corresponding to the current parse event
* @throws NoSuchElementException if this is called when
* {@link #hasNext() hasNext()} returns false
* @throws XMLStreamException if there is an error processing the
* underlying DTD source
*/
public int next() throws XMLStreamException;
/**
* Returns true if there are more parsing events and
* false if there are no more events. This method will return
* false if the current state of the DTDStreamReader is
* {@link #END_DTD END_DTD}
*
* @return true if there are more events, false
* otherwise
* @throws XMLStreamException if there is a fatal error detecting the next
* state
*/
public boolean hasNext() throws XMLStreamException;
/**
* Returns an integer code that indicates the type of the event at
* the current cursor location.
*
* @return the integer code corresponding to the current parse event
*/
public int getEventType();
/**
* Returns the current value of the parse event as a string.
* This returns the value of a {@link #COMMENT COMMENT} or the replacement
* value for an {@link #ENTITY_DECLARATION ENTITY_DECLARATION}. This
* method returns null if there is no text available.
*
* @return the current text or null if there is no text available
* @throws java.lang.IllegalStateException if this state is not a valid
* text state.
*/
public String getText();
/**
* Returns an array which contains the characters from this event.
* This array should be treated as read-only and transient: the array
* will contain the text characters only until the DTDStreamReader
* moves on to the next event.
* Attempts to hold onto the character array beyond that time or
* modify the contents of the array are breaches of the contract for this
* interface.
*
* @return the current text or an empty array
* @throws java.lang.IllegalStateException if this state is not a valid
* text state.
*/
public char[] getTextCharacters();
/**
* Returns the offset into the text character array at which the first
* character of the data for the current event is located.
*
* @return the offset of the first character
* @throws java.lang.IllegalStateException if this state is not a valid
* text state.
*/
public int getTextStart();
/**
* Returns the length of the sequence of characters for the current event
* within the text character array. This method returns -1
* if there is no text available.
*
* @return the length of the character sequence for current event or
* -1
* @throws java.lang.IllegalStateException if this state is not a valid
* text state.
*/
public int getTextLength();
/**
* Returns the current location of the processor.
* If the location is unknown the processor should return an
* implementation
* of {@link Location Location} that returns -1 for
* each of the lineNumber, columnNumber, and characterOffset,
* and null for each of the publicId and systemId.
* The location information is only valid until {@link #next() next()}
* is called.
*
* @return the {@link Location Location} object
*/
public Location getLocation();
/**
* Returns the target of a processing instruction.
*
* @return the target or null
* @throws java.lang.IllegalStateException if this method is not valid in
* the current state.
*/
public String getPITarget();
/**
* Returns the data section of a processing instruction.
*
* @return the data or null
* @throws java.lang.IllegalStateException if this method is not valid in
* the current state.
*/
public String getPIData();
/**
* Returns the name as a String.
*
* @return the name
* @throws java.lang.IllegalStateException if this state is not a valid
* text state.
*/
public String getName();
/**
* Returns the public identifier.
*
* @return the public identifier, or null if not available
* @throws java.lang.IllegalStateException if this method is not valid in
* the current state.
*/
public String getPublicIdentifier();
/**
* Returns the system identifier.
*
* @return the system identifier, or null if not available
* @throws java.lang.IllegalStateException if this method is not valid in
* the current state.
*/
public String getSystemIdentifier();
/**
* Returns the notation name.
*
* @return the notation name
* @throws java.lang.IllegalStateException if this method is not valid in
* the current state.
*/
public String getNotationName();
/**
* Terminates DTD processing, skipping all DTD related events up
* to {@link #END_DTD END_DTD}. This method does not close the
* underlying input source.
* If this method is called when current state is already
* {@link #END_DTD END_DTD}, this method does nothing.
* Once this method has been invoked,
* method {@link #hasNext() hasNext()} returns false,
* method {@link #getEventType() getEventType()} returns
* {@link #END_DTD END_DTD} and any other method call except
* {@link #next() next()} or {@link #getLocation() getLocation()}
* on this interface generates an
* java.lang.IllegalStateException.
*
* @throws XMLStreamException if there is an error processing the
* underlying DTD source
*/
public void close() throws XMLStreamException;
}