// AttributesImpl.java - default implementation of Attributes. // http://www.saxproject.org // Written by David Megginson // NO WARRANTY! This class is in the public domain. // $Id: AttributesImpl.java,v 1.9 2002/01/30 20:52:24 dbrownell Exp $ package org.xml.sax.helpers; import org.xml.sax.Attributes; /** * Default implementation of the Attributes interface. * *
* This module, both source code and documentation, is in the * Public Domain, and comes with NO WARRANTY. * See http://www.saxproject.org * for further information. *
* *

This class provides a default implementation of the SAX2 * {@link org.xml.sax.Attributes Attributes} interface, with the * addition of manipulators so that the list can be modified or * reused.

* *

There are two typical uses of this class:

* *
    *
  1. to take a persistent snapshot of an Attributes object * in a {@link org.xml.sax.ContentHandler#startElement startElement} event; or
  2. *
  3. to construct or modify an Attributes object in a SAX2 driver or filter.
  4. *
* *

This class replaces the now-deprecated SAX1 {@link * org.xml.sax.helpers.AttributeListImpl AttributeListImpl} * class; in addition to supporting the updated Attributes * interface rather than the deprecated {@link org.xml.sax.AttributeList * AttributeList} interface, it also includes a much more efficient * implementation using a single array rather than a set of Vectors.

* * @since SAX 2.0 * @author David Megginson * @version 2.0.1 (sax2r2) */ public class AttributesImpl implements Attributes { //////////////////////////////////////////////////////////////////// // Constructors. //////////////////////////////////////////////////////////////////// /** * Construct a new, empty AttributesImpl object. */ public AttributesImpl () { length = 0; data = null; } /** * Copy an existing Attributes object. * *

This constructor is especially useful inside a * {@link org.xml.sax.ContentHandler#startElement startElement} event.

* * @param atts The existing Attributes object. */ public AttributesImpl (Attributes atts) { setAttributes(atts); } //////////////////////////////////////////////////////////////////// // Implementation of org.xml.sax.Attributes. //////////////////////////////////////////////////////////////////// /** * Return the number of attributes in the list. * * @return The number of attributes in the list. * @see org.xml.sax.Attributes#getLength */ public int getLength () { return length; } /** * Return an attribute's Namespace URI. * * @param index The attribute's index (zero-based). * @return The Namespace URI, the empty string if none is * available, or null if the index is out of range. * @see org.xml.sax.Attributes#getURI */ public String getURI (int index) { if (index >= 0 && index < length) { return data[index*5]; } else { return null; } } /** * Return an attribute's local name. * * @param index The attribute's index (zero-based). * @return The attribute's local name, the empty string if * none is available, or null if the index if out of range. * @see org.xml.sax.Attributes#getLocalName */ public String getLocalName (int index) { if (index >= 0 && index < length) { return data[index*5+1]; } else { return null; } } /** * Return an attribute's qualified (prefixed) name. * * @param index The attribute's index (zero-based). * @return The attribute's qualified name, the empty string if * none is available, or null if the index is out of bounds. * @see org.xml.sax.Attributes#getQName */ public String getQName (int index) { if (index >= 0 && index < length) { return data[index*5+2]; } else { return null; } } /** * Return an attribute's type by index. * * @param index The attribute's index (zero-based). * @return The attribute's type, "CDATA" if the type is unknown, or null * if the index is out of bounds. * @see org.xml.sax.Attributes#getType(int) */ public String getType (int index) { if (index >= 0 && index < length) { return data[index*5+3]; } else { return null; } } /** * Return an attribute's value by index. * * @param index The attribute's index (zero-based). * @return The attribute's value or null if the index is out of bounds. * @see org.xml.sax.Attributes#getValue(int) */ public String getValue (int index) { if (index >= 0 && index < length) { return data[index*5+4]; } else { return null; } } /** * Look up an attribute's index by Namespace name. * *

In many cases, it will be more efficient to look up the name once and * use the index query methods rather than using the name query methods * repeatedly.

* * @param uri The attribute's Namespace URI, or the empty * string if none is available. * @param localName The attribute's local name. * @return The attribute's index, or -1 if none matches. * @see org.xml.sax.Attributes#getIndex(java.lang.String,java.lang.String) */ public int getIndex (String uri, String localName) { int max = length * 5; for (int i = 0; i < max; i += 5) { if (data[i].equals(uri) && data[i+1].equals(localName)) { return i / 5; } } return -1; } /** * Look up an attribute's index by qualified (prefixed) name. * * @param qName The qualified name. * @return The attribute's index, or -1 if none matches. * @see org.xml.sax.Attributes#getIndex(java.lang.String) */ public int getIndex (String qName) { int max = length * 5; for (int i = 0; i < max; i += 5) { if (data[i+2].equals(qName)) { return i / 5; } } return -1; } /** * Look up an attribute's type by Namespace-qualified name. * * @param uri The Namespace URI, or the empty string for a name * with no explicit Namespace URI. * @param localName The local name. * @return The attribute's type, or null if there is no * matching attribute. * @see org.xml.sax.Attributes#getType(java.lang.String,java.lang.String) */ public String getType (String uri, String localName) { int max = length * 5; for (int i = 0; i < max; i += 5) { if (data[i].equals(uri) && data[i+1].equals(localName)) { return data[i+3]; } } return null; } /** * Look up an attribute's type by qualified (prefixed) name. * * @param qName The qualified name. * @return The attribute's type, or null if there is no * matching attribute. * @see org.xml.sax.Attributes#getType(java.lang.String) */ public String getType (String qName) { int max = length * 5; for (int i = 0; i < max; i += 5) { if (data[i+2].equals(qName)) { return data[i+3]; } } return null; } /** * Look up an attribute's value by Namespace-qualified name. * * @param uri The Namespace URI, or the empty string for a name * with no explicit Namespace URI. * @param localName The local name. * @return The attribute's value, or null if there is no * matching attribute. * @see org.xml.sax.Attributes#getValue(java.lang.String,java.lang.String) */ public String getValue (String uri, String localName) { int max = length * 5; for (int i = 0; i < max; i += 5) { if (data[i].equals(uri) && data[i+1].equals(localName)) { return data[i+4]; } } return null; } /** * Look up an attribute's value by qualified (prefixed) name. * * @param qName The qualified name. * @return The attribute's value, or null if there is no * matching attribute. * @see org.xml.sax.Attributes#getValue(java.lang.String) */ public String getValue (String qName) { int max = length * 5; for (int i = 0; i < max; i += 5) { if (data[i+2].equals(qName)) { return data[i+4]; } } return null; } //////////////////////////////////////////////////////////////////// // Manipulators. //////////////////////////////////////////////////////////////////// /** * Clear the attribute list for reuse. * *

Note that little memory is freed by this call: * the current array is kept so it can be * reused.

*/ public void clear () { if (data != null) { for (int i = 0; i < (length * 5); i++) data [i] = null; } length = 0; } /** * Copy an entire Attributes object. * *

It may be more efficient to reuse an existing object * rather than constantly allocating new ones.

* * @param atts The attributes to copy. */ public void setAttributes (Attributes atts) { clear(); length = atts.getLength(); if (length > 0) { data = new String[length*5]; for (int i = 0; i < length; i++) { data[i*5] = atts.getURI(i); data[i*5+1] = atts.getLocalName(i); data[i*5+2] = atts.getQName(i); data[i*5+3] = atts.getType(i); data[i*5+4] = atts.getValue(i); } } } /** * Add an attribute to the end of the list. * *

For the sake of speed, this method does no checking * to see if the attribute is already in the list: that is * the responsibility of the application.

* * @param uri The Namespace URI, or the empty string if * none is available or Namespace processing is not * being performed. * @param localName The local name, or the empty string if * Namespace processing is not being performed. * @param qName The qualified (prefixed) name, or the empty string * if qualified names are not available. * @param type The attribute type as a string. * @param value The attribute value. */ public void addAttribute (String uri, String localName, String qName, String type, String value) { ensureCapacity(length+1); data[length*5] = uri; data[length*5+1] = localName; data[length*5+2] = qName; data[length*5+3] = type; data[length*5+4] = value; length++; } /** * Set an attribute in the list. * *

For the sake of speed, this method does no checking * for name conflicts or well-formedness: such checks are the * responsibility of the application.

* * @param index The index of the attribute (zero-based). * @param uri The Namespace URI, or the empty string if * none is available or Namespace processing is not * being performed. * @param localName The local name, or the empty string if * Namespace processing is not being performed. * @param qName The qualified name, or the empty string * if qualified names are not available. * @param type The attribute type as a string. * @param value The attribute value. * @exception java.lang.ArrayIndexOutOfBoundsException When the * supplied index does not point to an attribute * in the list. */ public void setAttribute (int index, String uri, String localName, String qName, String type, String value) { if (index >= 0 && index < length) { data[index*5] = uri; data[index*5+1] = localName; data[index*5+2] = qName; data[index*5+3] = type; data[index*5+4] = value; } else { badIndex(index); } } /** * Remove an attribute from the list. * * @param index The index of the attribute (zero-based). * @exception java.lang.ArrayIndexOutOfBoundsException When the * supplied index does not point to an attribute * in the list. */ public void removeAttribute (int index) { if (index >= 0 && index < length) { if (index < length - 1) { System.arraycopy(data, (index+1)*5, data, index*5, (length-index-1)*5); } index = (length - 1) * 5; data [index++] = null; data [index++] = null; data [index++] = null; data [index++] = null; data [index] = null; length--; } else { badIndex(index); } } /** * Set the Namespace URI of a specific attribute. * * @param index The index of the attribute (zero-based). * @param uri The attribute's Namespace URI, or the empty * string for none. * @exception java.lang.ArrayIndexOutOfBoundsException When the * supplied index does not point to an attribute * in the list. */ public void setURI (int index, String uri) { if (index >= 0 && index < length) { data[index*5] = uri; } else { badIndex(index); } } /** * Set the local name of a specific attribute. * * @param index The index of the attribute (zero-based). * @param localName The attribute's local name, or the empty * string for none. * @exception java.lang.ArrayIndexOutOfBoundsException When the * supplied index does not point to an attribute * in the list. */ public void setLocalName (int index, String localName) { if (index >= 0 && index < length) { data[index*5+1] = localName; } else { badIndex(index); } } /** * Set the qualified name of a specific attribute. * * @param index The index of the attribute (zero-based). * @param qName The attribute's qualified name, or the empty * string for none. * @exception java.lang.ArrayIndexOutOfBoundsException When the * supplied index does not point to an attribute * in the list. */ public void setQName (int index, String qName) { if (index >= 0 && index < length) { data[index*5+2] = qName; } else { badIndex(index); } } /** * Set the type of a specific attribute. * * @param index The index of the attribute (zero-based). * @param type The attribute's type. * @exception java.lang.ArrayIndexOutOfBoundsException When the * supplied index does not point to an attribute * in the list. */ public void setType (int index, String type) { if (index >= 0 && index < length) { data[index*5+3] = type; } else { badIndex(index); } } /** * Set the value of a specific attribute. * * @param index The index of the attribute (zero-based). * @param value The attribute's value. * @exception java.lang.ArrayIndexOutOfBoundsException When the * supplied index does not point to an attribute * in the list. */ public void setValue (int index, String value) { if (index >= 0 && index < length) { data[index*5+4] = value; } else { badIndex(index); } } //////////////////////////////////////////////////////////////////// // Internal methods. //////////////////////////////////////////////////////////////////// /** * Ensure the internal array's capacity. * * @param n The minimum number of attributes that the array must * be able to hold. */ private void ensureCapacity (int n) { if (n <= 0) { return; } int max; if (data == null || data.length == 0) { max = 25; } else if (data.length >= n * 5) { return; } else { max = data.length; } while (max < n * 5) { max *= 2; } String newData[] = new String[max]; if (length > 0) { System.arraycopy(data, 0, newData, 0, length*5); } data = newData; } /** * Report a bad array index in a manipulator. * * @param index The index to report. * @exception java.lang.ArrayIndexOutOfBoundsException Always. */ private void badIndex (int index) throws ArrayIndexOutOfBoundsException { String msg = "Attempt to modify attribute at illegal index: " + index; throw new ArrayIndexOutOfBoundsException(msg); } //////////////////////////////////////////////////////////////////// // Internal state. //////////////////////////////////////////////////////////////////// int length; String data []; } // end of AttributesImpl.java