Java/XML/DOM Attribute
Содержание
- 1 An Attributes implementation that can perform more operations than the attribute list helper supplied with the standard SAX2 distribution.
- 2 Copy the attribues on one element to the other
- 3 Find Container With Attribute Value Or Create
- 4 Find Container With Attribute Value Or Create And Set
- 5 Find the first direct child with a given attribute.
- 6 Get all the attributes for an Element
- 7 Get an Attribute from an Element. Returns an empty String if none found
- 8 Get Attribute
- 9 Get Attribute by QName
- 10 Get attribute"s value
- 11 Output XML element Attributes
- 12 Recursive method to find a given attribute value
- 13 Returns null, not "", for a nonexistent attribute
- 14 Return the right attribute node
- 15 Return the value of the attribute of the given element with the given name
- 16 Retutns the value of the named attribute of the given element.
- 17 Set an Attribute in an Element
- 18 Set Attribute
An Attributes implementation that can perform more operations than the attribute list helper supplied with the standard SAX2 distribution.
<source lang="java">
/*
* Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */
import org.xml.sax.Attributes; /**
* An Attributes implementation that can perform more operations than the * attribute list helper supplied with the standard SAX2 distribution. */
public class AttributesImpl implements Attributes {
//
// Data
//
/** Head node. */
private ListNode head;
/** Tail node. */
private ListNode tail;
/** Length. */
private int length;
//
// Attributes methods
//
/** Returns the number of attributes. */
public int getLength() {
return length;
}
/** Returns the index of the specified attribute. */
public int getIndex(String raw) {
ListNode place = head;
int index = 0;
while (place != null) {
if (place.raw.equals(raw)) {
return index;
}
index++;
place = place.next;
}
return -1;
}
/** Returns the index of the specified attribute. */
public int getIndex(String uri, String local) {
ListNode place = head;
int index = 0;
while (place != null) {
if (place.uri.equals(uri) && place.local.equals(local)) {
return index;
}
index++;
place = place.next;
}
return -1;
}
/** Returns the attribute URI by index. */
public String getURI(int index) {
ListNode node = getListNodeAt(index);
return node != null ? node.uri : null;
} // getURI(int):String
/** Returns the attribute local name by index. */
public String getLocalName(int index) {
ListNode node = getListNodeAt(index);
return node != null ? node.local : null;
} // getLocalName(int):String
/** Returns the attribute raw name by index. */
public String getQName(int index) {
ListNode node = getListNodeAt(index);
return node != null ? node.raw : null;
} // getQName(int):String
/** Returns the attribute type by index. */
public String getType(int index) {
ListNode node = getListNodeAt(index);
return (node != null) ? node.type : null;
} // getType(int):String
/** Returns the attribute type by uri and local. */
public String getType(String uri, String local) {
ListNode node = getListNode(uri, local);
return (node != null) ? node.type : null;
} // getType(String,String):String
/** Returns the attribute type by raw name. */
public String getType(String raw) {
ListNode node = getListNode(raw);
return (node != null) ? node.type : null;
} // getType(String):String
/** Returns the attribute value by index. */
public String getValue(int index) {
ListNode node = getListNodeAt(index);
return (node != null) ? node.value : null;
} // getType(int):String
/** Returns the attribute value by uri and local. */
public String getValue(String uri, String local) {
ListNode node = getListNode(uri, local);
return (node != null) ? node.value : null;
} // getType(String):String
/** Returns the attribute value by raw name. */
public String getValue(String raw) {
ListNode node = getListNode(raw);
return (node != null) ? node.value : null;
} // getType(String):String
//
// Public methods
//
/** Adds an attribute. */
public void addAttribute(String raw, String type, String value) {
addAttribute(null, null, raw, type, value);
}
/** Adds an attribute. */
public void addAttribute(String uri, String local, String raw, String type, String value) {
ListNode node = new ListNode(uri, local, raw, type, value);
if (length == 0) {
head = node;
} else {
tail.next = node;
}
tail = node;
length++;
} // addAttribute(String,StringString,String,String)
/** Inserts an attribute. */
public void insertAttributeAt(int index, String raw, String type, String value) {
insertAttributeAt(index, null, null, raw, type, value);
}
/** Inserts an attribute. */
public void insertAttributeAt(int index, String uri, String local, String raw, String type,
String value) {
// if list is empty, add attribute
if (length == 0 || index >= length) {
addAttribute(uri, local, raw, type, value);
return;
}
// insert at beginning of list
ListNode node = new ListNode(uri, local, raw, type, value);
if (index < 1) {
node.next = head;
head = node;
} else {
ListNode prev = getListNodeAt(index - 1);
node.next = prev.next;
prev.next = node;
}
length++;
} // insertAttributeAt(int,String,String,String,String,String)
/** Removes an attribute. */
public void removeAttributeAt(int index) {
if (length == 0) {
return;
}
if (index == 0) {
head = head.next;
if (head == null) {
tail = null;
}
length--;
} else {
ListNode prev = getListNodeAt(index - 1);
ListNode node = getListNodeAt(index);
if (node != null) {
prev.next = node.next;
if (node == tail) {
tail = prev;
}
length--;
}
}
} // removeAttributeAt(int)
/** Removes the specified attribute. */
public void removeAttribute(String raw) {
removeAttributeAt(getIndex(raw));
}
/** Removes the specified attribute. */
public void removeAttribute(String uri, String local) {
removeAttributeAt(getIndex(uri, local));
}
//
// Private methods
//
/** Returns the node at the specified index. */
private ListNode getListNodeAt(int i) {
for (ListNode place = head; place != null; place = place.next) {
if (--i == -1) {
return place;
}
}
return null;
} // getListNodeAt(int):ListNode
/** Returns the first node with the specified uri and local. */
public ListNode getListNode(String uri, String local) {
if (uri != null && local != null) {
ListNode place = head;
while (place != null) {
if (place.uri != null && place.local != null && place.uri.equals(uri)
&& place.local.equals(local)) {
return place;
}
place = place.next;
}
}
return null;
} // getListNode(String,String):ListNode
/** Returns the first node with the specified raw name. */
private ListNode getListNode(String raw) {
if (raw != null) {
for (ListNode place = head; place != null; place = place.next) {
if (place.raw != null && place.raw.equals(raw)) {
return place;
}
}
}
return null;
} // getListNode(String):ListNode
//
// Object methods
//
/** Returns a string representation of this object. */
public String toString() {
StringBuffer str = new StringBuffer();
str.append("[");
str.append("len=");
str.append(length);
str.append(", {");
for (ListNode place = head; place != null; place = place.next) {
str.append(place.toString());
if (place.next != null) {
str.append(", ");
}
}
str.append("}]");
return str.toString();
} // toString():String
//
// Classes
//
/**
* An attribute node.
*/
static class ListNode {
//
// Data
//
/** Attribute uri. */
public String uri;
/** Attribute local. */
public String local;
/** Attribute raw. */
public String raw;
/** Attribute type. */
public String type;
/** Attribute value. */
public String value;
/** Next node. */
public ListNode next;
//
// Constructors
//
/** Constructs a list node. */
public ListNode(String uri, String local, String raw, String type, String value) {
this.uri = uri;
this.local = local;
this.raw = raw;
this.type = type;
this.value = value;
} // <init>(String,String,String,String,String)
//
// Object methods
//
/** Returns string representation of this object. */
public String toString() {
return raw != null ? raw : local;
}
} // class ListNode
} // class AttributesImpl
</source>
Copy the attribues on one element to the other
<source lang="java">
import org.w3c.dom.Attr; import org.w3c.dom.Element; import org.w3c.dom.NamedNodeMap; public class Utils {
public static void copyAttributes(Element from, Element to) {
NamedNodeMap attributes = from.getAttributes();
for (int i = 0; i < attributes.getLength(); i++) {
Attr node = (Attr) attributes.item(i);
to.setAttributeNS(node.getNamespaceURI(), node.getName(), node.getValue());
}
}
}
</source>
Find Container With Attribute Value Or Create
<source lang="java">
import java.text.ParseException; import java.text.SimpleDateFormat; import java.util.ArrayList; import java.util.Date; import java.util.Iterator; import org.w3c.dom.Document; import org.w3c.dom.Element; import org.w3c.dom.Node; import org.w3c.dom.NodeList; /*******************************************************************************
* Copyright (C) 2007 Google Inc. * * Licensed under the Apache License, Version 2.0 (the "License"); you may not * use this file except in compliance with the License. You may obtain a copy of * the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations under * the License. ******************************************************************************/
/**
* Various XML utilities. * * @author simonjsmith, ksim * @version 1.1 - ksim - March 6th, 2007 - Added functions regarding streaming * @version 1.2 - ksim - March 10th, 2007 - Added functions regarding DOM * manipulation */
public class Utils {
public static Element findContainerWithAttributeValueElseCreate(
Document document, Element parent, String element,
String attributeName, String attributeValue) {
NodeList nl = parent.getElementsByTagName(element);
Element e;
for (int i = 0; i < nl.getLength(); i++) {
e = (Element) nl.item(i);
if (e.getAttribute(attributeName).equals(attributeValue)) {
return e;
}
}
e = document.createElement(element);
parent.appendChild(e);
e.setAttribute(attributeName, attributeValue);
return e;
}
}
</source>
Find Container With Attribute Value Or Create And Set
<source lang="java">
import java.text.ParseException; import java.text.SimpleDateFormat; import java.util.ArrayList; import java.util.Date; import java.util.Iterator; import org.w3c.dom.Document; import org.w3c.dom.Element; import org.w3c.dom.Node; import org.w3c.dom.NodeList; /*******************************************************************************
* Copyright (C) 2007 Google Inc. * * Licensed under the Apache License, Version 2.0 (the "License"); you may not * use this file except in compliance with the License. You may obtain a copy of * the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations under * the License. ******************************************************************************/
/**
* Various XML utilities. * * @author simonjsmith, ksim * @version 1.1 - ksim - March 6th, 2007 - Added functions regarding streaming * @version 1.2 - ksim - March 10th, 2007 - Added functions regarding DOM * manipulation */
public class Utils {
public static Element findContainerWithAttributeValueElseCreateAndSet(
Document document, Element parent, String element, String value,
String attributeName, String attributeValue) {
Element e = findContainerWithAttributeValueElseCreate(document, parent,
element, attributeName, attributeValue);
e.appendChild(document.createTextNode(value));
return e;
}
public static Element findContainerWithAttributeValueElseCreate(
Document document, Element parent, String element,
String attributeName, String attributeValue) {
NodeList nl = parent.getElementsByTagName(element);
Element e;
for (int i = 0; i < nl.getLength(); i++) {
e = (Element) nl.item(i);
if (e.getAttribute(attributeName).equals(attributeValue)) {
return e;
}
}
e = document.createElement(element);
parent.appendChild(e);
e.setAttribute(attributeName, attributeValue);
return e;
}
}
</source>
Find the first direct child with a given attribute.
<source lang="java">
import org.w3c.dom.Node; /**
* * * @author Costin Manolache */
public class Main {
/** Find the first direct child with a given attribute.
* @param parent
* @param elemName name of the element, or null for any
* @param attName attribute we"re looking for
* @param attVal attribute value or null if we just want any
*/
public static Node findChildWithAtt(Node parent, String elemName,
String attName, String attVal) {
Node child=DomUtil.getChild(parent, Node.ELEMENT_NODE);
if( attVal== null ) {
while( child!= null &&
( elemName==null || elemName.equals( child.getNodeName())) &&
DomUtil.getAttribute(child, attName) != null ) {
child=getNext(child, elemName, Node.ELEMENT_NODE );
}
} else {
while( child!= null &&
( elemName==null || elemName.equals( child.getNodeName())) &&
! attVal.equals( DomUtil.getAttribute(child, attName)) ) {
child=getNext(child, elemName, Node.ELEMENT_NODE );
}
}
return child;
}
/**
*/
public static Node getNext( Node current, String name, int type) {
Node first=current.getNextSibling();
if( first==null ) return null;
for (Node node = first; node != null;
node = node.getNextSibling()) {
if( type >= 0 && node.getNodeType() != type ) continue;
//System.out.println("getNode: " + name + " " + node.getNodeName());
if( name==null )
return node;
if( name.equals( node.getNodeName() ) ) {
return node;
}
}
return null;
}
}
</source>
Get all the attributes for an Element
<source lang="java">
import org.w3c.dom.Attr; import org.w3c.dom.Element; import org.w3c.dom.NamedNodeMap;
public class Main {
// get all the attributes for an Element
public static Attr[] getAttrs(Element elem) {
NamedNodeMap attrMap = elem.getAttributes();
Attr [] attrArray = new Attr[attrMap.getLength()];
for (int i=0; i<attrMap.getLength(); i++)
attrArray[i] = (Attr)attrMap.item(i);
return attrArray;
} // getAttrs(Element): Attr[]
}
</source>
Get an Attribute from an Element. Returns an empty String if none found
<source lang="java">
/**********************************************************************************
- Copyright (c) 2003, 2004 The Regents of the University of Michigan, Trustees of Indiana University,
- Board of Trustees of the Leland Stanford, Jr., University, and The MIT Corporation
- Licensed under the Educational Community License Version 1.0 (the "License");
- By obtaining, using and/or copying this Original Work, you agree that you have read,
- understand, and will comply with the terms and conditions of the Educational Community License.
- You may obtain a copy of the License at:
- http://cvs.sakaiproject.org/licenses/license_1_0.html
- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
- INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
- AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
- DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
- FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-
- /
import java.util.ArrayList; import java.util.List; import org.w3c.dom.Element; import org.w3c.dom.Node; import org.w3c.dom.NodeList; public class Utils {
/**
* Get an Attribute from an Element. Returns an empty String if none found
* @param element the containing Element
* @param name the attribute name
* @return Attribute as a String
*/
public static String getAttribute(Element element, String name) {
return element.getAttribute(name);
}
/**
* Return a list of named Elements with a specific attribute value.
* @param element the containing Element
* @param name the tag name
* @param attribute Attribute name
* @param value Attribute value
* @param returnFirst Return only the first matching value?
* @return List of matching elements
*/
public static List selectElementsByAttributeValue(Element element, String name,
String attribute, String value,
boolean returnFirst) {
NodeList elementList = element.getElementsByTagName(name);
List resultList = new ArrayList();
for (int i = 0; i < elementList.getLength(); i++) {
if (getAttribute((Element) elementList.item(i), attribute).equals(value)) {
resultList.add(elementList.item(i));
if (returnFirst) {
break;
}
}
}
return resultList;
}
}
</source>
Get Attribute
<source lang="java">
/**
* Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, * software distributed under the License is distributed on an * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * KIND, either express or implied. See the License for the * specific language governing permissions and limitations * under the License. */
import org.w3c.dom.NamedNodeMap; import org.w3c.dom.Node; /**
* Few simple utils to read DOM. This is originally from the Jakarta Commons * Modeler. * * @author Costin Manolache */
public class Utils {
public static String getAttribute(Node element, String attName) {
NamedNodeMap attrs = element.getAttributes();
if (attrs == null) {
return null;
}
Node attN = attrs.getNamedItem(attName);
if (attN == null) {
return null;
}
return attN.getNodeValue();
}
}
</source>
Get Attribute by QName
<source lang="java">
/**
* Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, * software distributed under the License is distributed on an * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * KIND, either express or implied. See the License for the * specific language governing permissions and limitations * under the License. */
import javax.xml.namespace.QName; import org.w3c.dom.Element; import org.w3c.dom.NamedNodeMap; import org.w3c.dom.Node; /**
* Few simple utils to read DOM. This is originally from the Jakarta Commons * Modeler. * * @author Costin Manolache */
public class Utils {
public static String getAttribute(Element element, QName attName) {
return element.getAttributeNS(attName.getNamespaceURI(), attName.getLocalPart());
} }
</source>
Get attribute"s value
<source lang="java">
import org.w3c.dom.Attr; import org.w3c.dom.Element; import org.w3c.dom.NamedNodeMap;
public class Main {
// get attribute"s value
public static String getValue(Attr attribute) {
return attribute.getValue();
} // getValue(Attr):String
}
</source>
Output XML element Attributes
<source lang="java">
import org.w3c.dom.Element; import org.w3c.dom.NamedNodeMap; import org.w3c.dom.Node; public class Utils {
public static void printAttributes(Element element) {
NamedNodeMap attributes = element.getAttributes();
for (int i = 0; i < attributes.getLength(); i++) {
Node node = attributes.item(i);
System.err.println("## prefix=" + node.getPrefix() + " localname:" + node.getLocalName()
+ " value=" + node.getNodeValue());
}
}
}
</source>
Recursive method to find a given attribute value
<source lang="java">
import javax.xml.namespace.QName; import org.w3c.dom.Document; import org.w3c.dom.Element; import org.w3c.dom.Node; public class Utils {
/**
* Recursive method to find a given attribute value
*/
public static String recursiveGetAttributeValue(Element element, String attributeName) {
String answer = null;
try {
answer = element.getAttribute(attributeName);
} catch (Exception e) {
}
if (answer == null || answer.length() == 0) {
Node parentNode = element.getParentNode();
if (parentNode instanceof Element) {
return recursiveGetAttributeValue((Element) parentNode, attributeName);
}
}
return answer;
}
}
</source>
Returns null, not "", for a nonexistent attribute
<source lang="java">
import org.w3c.dom.Attr; import org.w3c.dom.Element; public class Utils {
/**
* Returns null, not "", for a nonexistent attribute.
*
* @param e
* @param attributeName
* @return
*/
public static String getAttributeValueEmptyNull(Element e, String attributeName) {
Attr node = e.getAttributeNode(attributeName);
if (node == null) {
return null;
}
return node.getValue();
}
}
</source>
Return the right attribute node
<source lang="java">
import org.w3c.dom.Attr; import org.w3c.dom.Element;
public class Main {
// return the right attribute node
public static Attr getAttr(Element elem, String name) {
return elem.getAttributeNode(name);
} // getAttr(Element, String):Attr
}
</source>
Return the value of the attribute of the given element with the given name
<source lang="java">
import org.w3c.dom.Attr; import org.w3c.dom.Element; import org.w3c.dom.NamedNodeMap;
public class Main {
// return the value of the attribute of the given element
// with the given name
public static String getAttrValueNS(Element elem, String nsUri,
String localName) {
return elem.getAttributeNS(nsUri, localName);
} // getAttrValueNS(Element, String):Attr
}
</source>
Retutns the value of the named attribute of the given element.
<source lang="java">
import org.w3c.dom.Attr; import org.w3c.dom.Element; public class Utils {
/***
Retutns the value of the named attribute of the given * element. If there is no such attribute, returns null.
*
* @param element element
* @param name name
* @return value
*/
public static String getAttributeValue(Element element, String name)
{
Attr attribute = element.getAttributeNode(name);
if(attribute == null) {
return null;
}
else {
return attribute.getValue();
}
}
}
</source>
Set an Attribute in an Element
<source lang="java">
import org.w3c.dom.Element; public class Utils {
/**
* Set an Attribute in an Element
* @param element the containing Element
* @param name the attribute name
* @param value the attribute value
*/
public static void setAttribute(Element element, String name, String value) {
element.setAttribute(name, value);
}
}
</source>
Set Attribute
<source lang="java">
/**
* Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, * software distributed under the License is distributed on an * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * KIND, either express or implied. See the License for the * specific language governing permissions and limitations * under the License. */
import javax.xml.namespace.QName; import org.w3c.dom.Element; import org.w3c.dom.NamedNodeMap; import org.w3c.dom.Node; /**
* Few simple utils to read DOM. This is originally from the Jakarta Commons * Modeler. * * @author Costin Manolache */
public class Utils {
public static void setAttribute(Node node, String attName, String val) {
NamedNodeMap attributes = node.getAttributes();
Node attNode = node.getOwnerDocument().createAttribute(attName);
attNode.setNodeValue(val);
attributes.setNamedItem(attNode);
} }
</source>
