Class Element
- Object
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- nu.xom.Node
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- nu.xom.ParentNode
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- nu.xom.Element
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public class Element extends ParentNode
This class represents an XML element. Each element has the following properties:
- Local name
- Prefix (which may be null or the empty string)
- Namespace URI (which may be null or the empty string)
- A list of attributes
- A list of namespace declarations for this element (not including those inherited from its parent)
- A list of child nodes
- Version:
- 1.2.10
- Author:
- Elliotte Rusty Harold
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
addAttribute(Attribute attribute)
Adds an attribute to this element, replacing any existing attribute with the same local name and namespace URI.void
addNamespaceDeclaration(String prefix, String uri)
Declares a namespace prefix.void
appendChild(String text)
Converts a string to a text node and appends that node to the children of this node.Node
copy()
Creates a deep copy of this element with no parent, that can be added to this document or a different one.Attribute
getAttribute(int index)
Selects an attribute by index.Attribute
getAttribute(String name)
Returns the attribute with the specified name in no namespace, or null if this element does not have an attribute with that name in no namespace.Attribute
getAttribute(String localName, String namespaceURI)
Returns the attribute with the specified name and namespace URI, or null if this element does not have an attribute with that name in that namespace.int
getAttributeCount()
Returns the number of attributes of thisElement
, not counting namespace declarations.String
getAttributeValue(String name)
Returns the value of the attribute with the specified name in no namespace, or null if this element does not have an attribute with that name.String
getAttributeValue(String localName, String namespaceURI)
Returns the value of the attribute with the specified name and namespace URI, or null if this element does not have such an attribute.String
getBaseURI()
Returns the absolute base URI against which relative URIs in this element should be resolved.Elements
getChildElements()
Returns a list of all the child elements of this element in document order.Elements
getChildElements(String name)
Returns a list of the child elements of this element with the specified name in no namespace.Elements
getChildElements(String localName, String namespaceURI)
Returns a list of the immediate child elements of this element with the specified local name and namespace URI.Element
getFirstChildElement(String name)
Returns the first child element with the specified name in no namespace.Element
getFirstChildElement(String localName, String namespaceURI)
Returns the first child element with the specified local name and namespace URI.String
getLocalName()
Returns the local name of this element, not including the namespace prefix or colon.int
getNamespaceDeclarationCount()
Returns the number of namespace declarations on this element.String
getNamespacePrefix()
Returns the prefix of this element, or the empty string if this element does not have a prefix.String
getNamespacePrefix(int index)
Returns the indexth namespace prefix declared on this element.String
getNamespaceURI()
Returns the namespace URI of this element, or the empty string if this element is not in a namespace.String
getNamespaceURI(String prefix)
Returns the namespace URI mapped to the specified prefix within this element.String
getQualifiedName()
Returns the complete name of this element, including the namespace prefix if this element has one.String
getValue()
Returns the value of the element as defined by XPath 1.0.void
insertChild(String text, int position)
Converts a string to a text node and inserts that node at the specified position.Attribute
removeAttribute(Attribute attribute)
Removes an attribute from this element.Nodes
removeChildren()
Detaches all children from this node.void
removeNamespaceDeclaration(String prefix)
Removes the mapping of the specified prefix.void
setBaseURI(String URI)
Sets the URI from which this element was loaded, and against which relative URLs in this element will be resolved, unless anxml:base
attribute overrides this.void
setLocalName(String localName)
Sets the local name of this element.void
setNamespacePrefix(String prefix)
Sets the namespace prefix of this element.void
setNamespaceURI(String uri)
Sets the namespace URI of this element.protected Element
shallowCopy()
Creates a very shallow copy of the element with the same name and namespace URI, but no children, attributes, base URI, or namespace declaration.String
toString()
Returns a string representation of this element suitable for debugging and diagnosis.String
toXML()
Returns a string containing the XML serialization of this element.-
Methods inherited from class nu.xom.ParentNode
appendChild, getChild, getChildCount, indexOf, insertChild, removeChild, removeChild, replaceChild
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Constructor Detail
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Element
public Element(String name)
Creates a new element in no namespace.
- Parameters:
name
- the name of the element- Throws:
IllegalNameException
- ifname
is not a legal XML 1.0 non-colonized name
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Element
public Element(String name, String uri)
Creates a new element in a namespace.
- Parameters:
name
- the qualified name of the elementuri
- the namespace URI of the element- Throws:
IllegalNameException
- ifname
is not a legal XML 1.0 nameNamespaceConflictException
- ifname
's prefix cannot be used withuri
MalformedURIException
- ifuri
is not an RFC 3986 absolute URI reference
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Element
public Element(Element element)
Creates a deep copy of an element. The copy is disconnected from the tree, and does not have a parent.
- Parameters:
element
- the element to copy
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Method Detail
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getChildElements
public final Elements getChildElements(String name)
Returns a list of the child elements of this element with the specified name in no namespace. The elements returned are in document order.
- Parameters:
name
- the name of the elements included in the list- Returns:
- a comatose list containing the child elements of this element with the specified name
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getChildElements
public final Elements getChildElements(String localName, String namespaceURI)
Returns a list of the immediate child elements of this element with the specified local name and namespace URI. Passing the empty string or null as the local name returns all elements in the specified namespace. Passing null or the empty string as the namespace URI returns elements with the specified name in no namespace. The elements returned are in document order.
- Parameters:
localName
- the name of the elements included in the listnamespaceURI
- the namespace URI of the elements included in the list- Returns:
- a comatose list containing the child elements of this element with the specified name in the specified namespace
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getChildElements
public final Elements getChildElements()
Returns a list of all the child elements of this element in document order.
- Returns:
- a comatose list containing all child elements of this element
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getFirstChildElement
public final Element getFirstChildElement(String name)
Returns the first child element with the specified name in no namespace. If there is no such element, it returns null.
- Parameters:
name
- the name of the element to return- Returns:
- the first child element with the specified local name in no namespace or null if there is no such element
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getFirstChildElement
public final Element getFirstChildElement(String localName, String namespaceURI)
Returns the first child element with the specified local name and namespace URI. If there is no such element, it returns null.
- Parameters:
localName
- the local name of the element to returnnamespaceURI
- the namespace URI of the element to return- Returns:
- the first child with the specified local name in the specified namespace, or null if there is no such element
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addAttribute
public void addAttribute(Attribute attribute)
Adds an attribute to this element, replacing any existing attribute with the same local name and namespace URI.
- Parameters:
attribute
- the attribute to add- Throws:
MultipleParentException
- if the attribute is already attached to an elementNamespaceConflictException
- if the attribute's prefix is mapped to a different namespace URI than the same prefix is mapped to by this element, another attribute of this element, or an additional namespace declaration of this element
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removeAttribute
public Attribute removeAttribute(Attribute attribute)
Removes an attribute from this element.
- Parameters:
attribute
- the attribute to remove- Returns:
- the attribute that was removed
- Throws:
NoSuchAttributeException
- if this element is not the parent of attribute
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getAttribute
public final Attribute getAttribute(String name)
Returns the attribute with the specified name in no namespace, or null if this element does not have an attribute with that name in no namespace.
- Parameters:
name
- the name of the attribute- Returns:
- the attribute of this element with the specified name
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getAttribute
public final Attribute getAttribute(String localName, String namespaceURI)
Returns the attribute with the specified name and namespace URI, or null if this element does not have an attribute with that name in that namespace.
- Parameters:
localName
- the local name of the attributenamespaceURI
- the namespace of the attribute- Returns:
- the attribute of this element with the specified name and namespace
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getAttributeValue
public final String getAttributeValue(String name)
Returns the value of the attribute with the specified name in no namespace, or null if this element does not have an attribute with that name.
- Parameters:
name
- the name of the attribute- Returns:
- the value of the attribute of this element with the specified name
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getAttributeCount
public final int getAttributeCount()
Returns the number of attributes of this
Element
, not counting namespace declarations. This is always a non-negative number.- Returns:
- the number of attributes in the container
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getAttribute
public final Attribute getAttribute(int index)
Selects an attribute by index. The index is purely for convenience and has no particular meaning. In particular, it is not necessarily the position of this attribute in the original document from which this
Element
object was read. As with most lists in Java, attributes are numbered from 0 to one less than the length of the list.In general, you should not add attributes to or remove attributes from the list while iterating across it. Doing so will change the indexes of the other attributes in the list. it is, however, safe to remove an attribute from either end of the list (0 or
getAttributeCount()-1
) until there are no attributes left.- Parameters:
index
- the attribute to return- Returns:
- the indexth attribute of this element
- Throws:
IndexOutofBoundsException
- if the index is negative or greater than or equal to the number of attributes of this element
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getAttributeValue
public final String getAttributeValue(String localName, String namespaceURI)
Returns the value of the attribute with the specified name and namespace URI, or null if this element does not have such an attribute.
- Parameters:
localName
- the name of the attributenamespaceURI
- the namespace of the attribute- Returns:
- the value of the attribute of this element with the specified name and namespace
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getLocalName
public final String getLocalName()
Returns the local name of this element, not including the namespace prefix or colon.
- Returns:
- the local name of this element
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getQualifiedName
public final String getQualifiedName()
Returns the complete name of this element, including the namespace prefix if this element has one.
- Returns:
- the qualified name of this element
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getNamespacePrefix
public final String getNamespacePrefix()
Returns the prefix of this element, or the empty string if this element does not have a prefix.
- Returns:
- the prefix of this element
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getNamespaceURI
public final String getNamespaceURI()
Returns the namespace URI of this element, or the empty string if this element is not in a namespace.
- Returns:
- the namespace URI of this element
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getNamespaceURI
public final String getNamespaceURI(String prefix)
Returns the namespace URI mapped to the specified prefix within this element. Returns null if this prefix is not associated with a URI.
- Parameters:
prefix
- the namespace prefix whose URI is desired- Returns:
- the namespace URI mapped to
prefix
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setLocalName
public void setLocalName(String localName)
Sets the local name of this element.
- Parameters:
localName
- the new local name- Throws:
IllegalNameException
- iflocalName
is not a legal, non-colonized name
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setNamespaceURI
public void setNamespaceURI(String uri)
Sets the namespace URI of this element.
- Parameters:
uri
- the new namespace URI- Throws:
MalformedURIException
- ifuri
is not an absolute RFC 3986 URI referenceNamespaceException
- if this element has a prefix anduri
is null or the empty string; or if the element's prefix is shared by an attribute or additional namespace
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setNamespacePrefix
public void setNamespacePrefix(String prefix)
Sets the namespace prefix of this element. You can pass null or the empty string to remove the prefix.
- Parameters:
prefix
- the new namespace prefix- Throws:
IllegalNameException
- ifprefix
is not a legal XML non-colonized nameNamespaceConflictException
- ifprefix
is already in use by an attribute or additional namespace with a different URI than the element itself
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insertChild
public void insertChild(String text, int position)
Converts a string to a text node and inserts that node at the specified position.
- Parameters:
position
- where to insert the childtext
- the string to convert to a text node and insert- Throws:
NullPointerException
- if text is nullIndexOutOfBoundsException
- if the position is negative or greater than the number of children of the node
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appendChild
public void appendChild(String text)
Converts a string to a text node and appends that node to the children of this node.
- Parameters:
text
- String to add to this node- Throws:
IllegalAddException
- if this node cannot have children of this typeNullPointerException
- iftext
is null
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removeChildren
public Nodes removeChildren()
Detaches all children from this node.
Subclassers should note that the default implementation of this method does not call
removeChild
ordetach
. If you overrideremoveChild
, you'll probably need to override this method as well.- Returns:
- a list of all the children removed in the order they appeared in the element
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addNamespaceDeclaration
public void addNamespaceDeclaration(String prefix, String uri)
Declares a namespace prefix. This is only necessary when prefixes are used in element content and attribute values, as in XSLT and the W3C XML Schema Language. Do not use this method to declare prefixes for element and attribute names.
You can supply an empty string for the prefix to declare a default namespace, provided the element itself has a prefix.
If you do redeclare a prefix that is already used by an element or attribute name, the additional namespace is added if and only if the URI is the same. Conflicting namespace declarations will throw an exception.
- Parameters:
prefix
- the prefix to declareuri
- the absolute URI reference to map the prefix to- Throws:
MalformedURIException
- ifURI
is not an RFC 3986 URI referenceIllegalNameException
- ifprefix
is not a legal XML non-colonized name or the empty stringNamespaceConflictException
- if the mapping conflicts with an existing element, attribute, or additional namespace declaration
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removeNamespaceDeclaration
public void removeNamespaceDeclaration(String prefix)
Removes the mapping of the specified prefix. This method only removes additional namespaces added with
addNamespaceDeclaration
. It has no effect on namespaces of elements and attributes. If the prefix is not used on this element, this method does nothing.- Parameters:
prefix
- the prefix whose declaration should be removed
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getNamespaceDeclarationCount
public final int getNamespaceDeclarationCount()
Returns the number of namespace declarations on this element. This counts the namespace of the element itself (which may be the empty string), the namespace of each attribute, and each namespace added by
addNamespaceDeclaration
. However, prefixes used multiple times are only counted once; and thexml
prefix used forxml:base
,xml:lang
, andxml:space
is not counted even if one of these attributes is present on the element.The return value is almost always positive. It can be zero if and only if the element itself has the prefix
xml
; e.g.<xml:space />
. This is not endorsed by the XML specification. The prefixxml
is reserved for use by the W3C, which has only used it for attributes to date. You really shouldn't do this. Nonetheless, this is not malformed so XOM allows it.- Returns:
- the number of namespaces declared by this element
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getNamespacePrefix
public final String getNamespacePrefix(int index)
Returns the indexth namespace prefix declared on this element. Namespaces inherited from ancestors are not included. The index is purely for convenience, and has no meaning in itself. This includes the namespaces of the element name and of all attributes' names (except for those with the prefix
xml
such asxml:space
) as well as additional declarations made for attribute values and element content. However, prefixes used multiple times (e.g. on several attribute values) are only reported once. The default namespace is reported with an empty string prefix if present. Like most lists in Java, the first prefix is at index 0.If the namespaces on the element change for any reason (adding or removing an attribute in a namespace, adding or removing a namespace declaration, changing the prefix of an element, etc.) then this method may skip or repeat prefixes. Don't change the prefixes of an element while iterating across them.
- Parameters:
index
- the prefix to return- Returns:
- the prefix
- Throws:
IndexOutOfBoundsException
- ifindex
is negative or greater than or equal to the number of namespaces declared by this element.
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setBaseURI
public void setBaseURI(String URI)
Sets the URI from which this element was loaded, and against which relative URLs in this element will be resolved, unless an
xml:base
attribute overrides this. Setting the base URI to null or the empty string removes any existing base URI.- Specified by:
setBaseURI
in classParentNode
- Parameters:
URI
- the new base URI for this element- Throws:
MalformedURIException
- ifURI
is not a legal RFC 3986 absolute URI
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getBaseURI
public String getBaseURI()
Returns the absolute base URI against which relative URIs in this element should be resolved.
xml:base
attributes in the same entity take precedence over the actual base URI of the document where the element was found or which was set bysetBaseURI
.This URI is made absolute before it is returned by resolving the information in this element against the information in its parent element and document entity. However, it is not always possible to fully absolutize the URI in all circumstances. In this case, this method returns the empty string to indicate the base URI of the current entity.
If the element's
xml:base
attribute contains a value that is a syntactically illegal URI (e.g. %GF.html"), then the base URI is application dependent. XOM's choice is to behave as if the element did not have anxml:base
attribute.- Overrides:
getBaseURI
in classNode
- Returns:
- the base URI of this element
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toXML
public final String toXML()
Returns a string containing the XML serialization of this element. This includes the element and all its attributes and descendants. However, it does not contain namespace declarations for namespaces inherited from ancestor elements.
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getValue
public final String getValue()
Returns the value of the element as defined by XPath 1.0. This is the complete PCDATA content of the element, without any tags, comments, or processing instructions after all entity and character references have been resolved.
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copy
public Node copy()
Creates a deep copy of this element with no parent, that can be added to this document or a different one.
Subclassers should be wary. Implementing this method is trickier than it might seem, especially if you wish to avoid potential stack overflows in deep documents. In particular, you should not rely on the obvious recursive algorithm. Most subclasses should override the
shallowCopy
method instead.
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shallowCopy
protected Element shallowCopy()
Creates a very shallow copy of the element with the same name and namespace URI, but no children, attributes, base URI, or namespace declaration. This method is invoked as necessary by the
copy
method and thecopy constructor
.Subclasses should override this method so that it returns an instance of the subclass so that types are preserved when copying. This method should not add any attributes, namespace declarations, or children to the shallow copy. Any such items will be overwritten.
- Returns:
- an empty element with the same name and namespace as this element
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toString
public String toString()
Returns a string representation of this element suitable for debugging and diagnosis. This is not the XML representation of the element.
- Overrides:
toString
in classObject
- Returns:
- a non-XML string representation of this element
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