org.granite.util.XMap Maven / Gradle / Ivy
/*
GRANITE DATA SERVICES
Copyright (C) 2011 GRANITE DATA SERVICES S.A.S.
This file is part of Granite Data Services.
Granite Data Services is free software; you can redistribute it and/or modify
it under the terms of the GNU Library General Public License as published by
the Free Software Foundation; either version 2 of the License, or (at your
option) any later version.
Granite Data Services 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 Library General Public License
for more details.
You should have received a copy of the GNU Library General Public License
along with this library; if not, see
* This class relies on JDK DOM & XPath built-in implementations.
*
* @author Franck WOLFF
*/
public class XMap implements Serializable {
private static final Logger log = Logger.getLogger(XMap.class);
private static final long serialVersionUID = 1L;
protected static final String DEFAULT_ROOT_NAME = "root";
/**
* An empty and unmodifiable XMap instance.
*/
public static final XMap EMPTY_XMAP = new XMap(null, null, false) {
private static final long serialVersionUID = 1L;
@Override
public String put(String key, String value) {
throw new RuntimeException("Immutable XMap");
}
@Override
public String remove(String key) {
throw new RuntimeException("Immutable XMap");
}
};
private transient DOM dom = null;
private transient Element root = null;
/**
* Constructs a new XMap instance.
*/
public XMap() {
this(null, null, false);
}
/**
* Constructs a new XMap instance.
*
* @param root the name of the root element (may be null).
*/
public XMap(String root) {
if (root != null) {
this.dom = new DOM();
this.root = dom.newDocument(root).getDocumentElement();
}
}
/**
* Constructs a new XMap instance from an XML input stream.
*
* @param input an XML input stream.
*/
public XMap(InputStream input) throws IOException, SAXException {
this.dom = new DOM();
this.root = dom.loadDocument(input).getDocumentElement();
}
/**
* Constructs a new XMap instance from an XML input stream.
*
* @param input an XML input stream.
*/
public XMap(InputStream input, EntityResolver resolver) throws IOException, SAXException {
this.dom = new DOM();
this.root = dom.loadDocument(input, resolver).getDocumentElement();
}
/**
* Constructs a new XMap instance.
*
* @param root a DOM element (may be null).
*/
public XMap(Element root) {
this(null, root, true);
}
/**
* Constructs a new XMap instance based on an existing XMap and clone its content.
*
* @param map the map to duplicate (root element is cloned so modification to this
* new instance won't modify the original XMap).
*/
public XMap(XMap map) {
this((map == null ? null : map.dom), (map == null ? null : map.root), true);
}
/**
* Constructs a new XMap instance.
*
* @param root the root element (may be null).
* @param clone should we clone the root element (prevent original node modification).
*/
protected XMap(DOM dom, Element root, boolean clone) {
this.dom = dom;
this.root = (clone && root != null ? (Element)root.cloneNode(true) : root);
}
/**
* Allows direct manipulation of the root element.
*
* @return the root element of this XMap instance.
*/
public Element getRoot() {
return root;
}
/**
* Returns the DOM instance of this XMap (one is created if it is null).
*
* @return the DOM instance of this XMap.
*/
protected DOM getDom() {
if (dom == null)
dom = new DOM();
return dom;
}
/**
* Returns true if the supplied key XPath expression matches at least one element, attribute
* or text in the root element of this XMap.
*
* @param key an XPath expression.
* @return true if the supplied key XPath expression matches at least one element, attribute
* or text in the root element of this XMap, false otherwise.
* @throws RuntimeException if the XPath expression isn't correct.
*/
public boolean containsKey(String key) {
if (root == null)
return false;
try {
Node result = getDom().selectSingleNode(root, key);
return (
result != null && (
result.getNodeType() == Node.ELEMENT_NODE ||
result.getNodeType() == Node.TEXT_NODE ||
result.getNodeType() == Node.ATTRIBUTE_NODE
)
);
} catch (Exception e) {
throw new RuntimeException(e);
}
}
/**
* Returns the text value of the element (or attribute or text) that matches the supplied
* XPath expression.
*
* @param key an XPath expression.
* @return the text value of the matched element or null if the element does not exist or have
* no value.
* @throws RuntimeException if the XPath expression isn't correct.
*/
public String get(String key) {
if (root == null)
return null;
try {
return getDom().getNormalizedValue(getDom().selectSingleNode(root, key));
} catch (Exception e) {
throw new RuntimeException(e);
}
}
public T get(String key, Class clazz, T defaultValue) {
return get(key, clazz, defaultValue, false, true);
}
public T get(String key, Class clazz, T defaultValue, boolean required, boolean warn) {
String sValue = get(key);
if (required && sValue == null)
throw new RuntimeException(key + " value is required in XML file:\n" + toString());
Object oValue = defaultValue;
boolean unsupported = false;
if (sValue != null) {
try {
if (clazz == String.class)
oValue = sValue;
else if (clazz == Integer.class || clazz == Integer.TYPE)
oValue = Integer.valueOf(sValue);
else if (clazz == Long.class || clazz == Long.TYPE)
oValue = Long.valueOf(sValue);
else if (clazz == Boolean.class || clazz == Boolean.TYPE) {
if (!Boolean.TRUE.toString().equalsIgnoreCase(sValue) && !Boolean.FALSE.toString().equalsIgnoreCase(sValue))
throw new NumberFormatException(sValue);
oValue = Boolean.valueOf(sValue);
}
else if (clazz == Double.class || clazz == Double.TYPE)
oValue = Double.valueOf(sValue);
else if (clazz == Float.class || clazz == Float.TYPE)
oValue = Float.valueOf(sValue);
else if (clazz == Short.class || clazz == Short.TYPE)
oValue = Short.valueOf(sValue);
else if (clazz == Byte.class || clazz == Byte.TYPE)
oValue = Byte.valueOf(sValue);
else
unsupported = true;
}
catch (Exception e) {
if (warn)
log.warn(e, "Illegal %s value for %s=%s (using default: %s)", clazz.getSimpleName(), key, sValue, defaultValue);
}
}
if (unsupported)
throw new UnsupportedOperationException("Unsupported value type: " + clazz.getName());
@SuppressWarnings("unchecked")
T tValue = (T)oValue;
return tValue;
}
/**
* Returns a list of XMap instances with all elements that match the
* supplied XPath expression. Note that XPath result nodes that are not instance of
* Element are ignored. Note also that returned XMaps contain original child elements of
* the root element of this XMap so modifications made to child elements affect this XMap
* instance as well.
*
* @param key an XPath expression.
* @return an unmodifiable list of XMap instances.
* @throws RuntimeException if the XPath expression isn't correct.
*/
public List getAll(String key) {
if (root == null)
return new ArrayList(0);
try {
List result = dom.selectNodes(root, key);
List xMaps = new ArrayList(result.size());
for (Node node : result) {
if (node.getNodeType() == Node.ELEMENT_NODE)
xMaps.add(new XMap(this.dom, (Element)node, false));
}
return xMaps;
} catch (Exception e) {
throw new RuntimeException(e);
}
}
/**
* Returns a new XMap instance with the first element that matches the
* supplied XPath expression or null if this XMap root element is null, or if XPath evaluation
* result is null, or this result is not an Element. Returned XMap contains original child element of
* the root element of this XMap so modifications made to the child element affect this XMap
* instance as well.
*
* @param key an XPath expression.
* @return a single new XMap instance.
* @throws RuntimeException if the XPath expression isn't correct.
*/
public XMap getOne(String key) {
if (root == null)
return null;
try {
Node node = getDom().selectSingleNode(root, key);
if (node == null || node.getNodeType() != Node.ELEMENT_NODE)
return null;
return new XMap(getDom(), (Element)node, false);
} catch (Exception e) {
throw new RuntimeException(e);
}
}
/**
* Creates or updates the text value of the element (or text or attribute) matched by
* the supplied XPath expression. If the matched element (or text or attribute) does not exist,
* it is created with the last segment of the XPath expression (but its parent must already exist).
*
* @param key an XPath expression.
* @param value the value to set (may be null).
* @return the previous value of the matched element (may be null).
* @throws RuntimeException if the root element of this XMap is null, if the XPath expression is not valid,
* or (creation case) if the parent node does not exist or is not an element instance.
*/
public String put(String key, String value) {
return put(key, value, false);
}
/**
* Creates or updates the text value of the element (or text or attribute) matched by
* the supplied XPath expression. If the matched element (or text or attribute) does not exist or if append
* is true, it is created with the last segment of the XPath expression (but its parent must already
* exist).
*
* @param key an XPath expression.
* @param value the value to set (may be null).
* @param append should the new element be appended (created) next to a possibly existing element(s) of
* the same name?
* @return the previous value of the matched element (may be null).
* @throws RuntimeException if the root element of this XMap is null, if the XPath expression is not valid,
* or (creation case) if the parent node does not exist or is not an element instance.
*/
public String put(String key, String value, boolean append) {
if (root == null)
root = getDom().newDocument(DEFAULT_ROOT_NAME).getDocumentElement();
if (!append) {
try {
Node selectResult = getDom().selectSingleNode(root, key);
if (selectResult != null)
return getDom().setValue(selectResult, value);
} catch(RuntimeException e) {
throw e;
} catch(Exception e) {
throw new RuntimeException(e);
}
}
Element parent = root;
String name = key;
int iLastSlash = key.lastIndexOf('/');
if (iLastSlash != -1) {
name = key.substring(iLastSlash + 1);
Node selectResult = null;
try {
selectResult = getDom().selectSingleNode(root, key.substring(0, iLastSlash));
} catch (Exception e) {
throw new RuntimeException(e);
}
if (selectResult == null)
throw new RuntimeException("Parent node does not exist: " + key.substring(0, iLastSlash));
if (!(selectResult instanceof Element))
throw new RuntimeException("Parent node must be an Element: " + key.substring(0, iLastSlash) + " -> " + selectResult);
parent = (Element)selectResult;
}
if (name.length() > 0 && name.charAt(0) == '@')
parent.setAttribute(name.substring(1), value);
else
getDom().newElement(parent, name, value);
return null;
}
/**
* Removes the element, text or attribute that matches the supplied XPath expression.
*
* @param key an XPath expression.
* @return the previous value of the matched node if any.
* @throws RuntimeException if the XPath expression isn't valid.
*/
public String remove(String key) {
if (root == null)
return null;
try {
Node node = getDom().selectSingleNode(root, key);
if (node != null) {
String value = getDom().getNormalizedValue(node);
if (node.getNodeType() == Node.ATTRIBUTE_NODE)
((Attr)node).getOwnerElement().removeAttribute(node.getNodeName());
else
node.getParentNode().removeChild(node);
return value;
}
} catch(Exception e) {
throw new RuntimeException(e);
}
return null;
}
/**
* Returns a "pretty" XML representation of the root element of this XMap (may be null).
*
* @return a "pretty" XML representation of the root element of this XMap (may be null).
*/
@Override
public String toString() {
return getDom().toString(root);
}
/**
* Write java.io.Serializable method.
*
* @param out the ObjectOutputStream where to write this XMap.
* @throws IOException if writing fails.
*/
private void writeObject(ObjectOutputStream out) throws IOException {
if (root == null)
out.writeInt(0);
else {
ByteArrayOutputStream output = new ByteArrayOutputStream();
try {
getDom().saveDocument(root.getOwnerDocument(), output);
} catch (TransformerException e) {
IOException ioe = new IOException("Could not serialize this XMap");
ioe.initCause(e);
throw ioe;
}
out.writeInt(output.size());
out.write(output.toByteArray());
}
}
/**
* Read java.io.Serializable method.
*
* @param in the ObjectInputStream from which to read this XMap.
* @throws IOException if readind fails.
*/
@SuppressWarnings("unused")
private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
int size = in.readInt();
if (size > 0) {
byte[] content = new byte[size];
in.readFully(content);
Document doc = null;
try {
doc = getDom().loadDocument(new ByteArrayInputStream(content));
} catch (Exception e) {
IOException ioe = new IOException("Could not deserialize this XMap");
ioe.initCause(e);
throw ioe;
}
if (doc != null && doc.getDocumentElement() != null)
this.root = doc.getDocumentElement();
}
}
}
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