Mega Code Archive
XML configuration management
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import org.w3c.dom.*;
import org.xml.sax.InputSource;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.*;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import java.io.*;
import java.util.*;
/**
* XML configuration management.
* <p/>
* This class uses DOM paths of a specific form to refer to nodes in the XML document.
* Consider this XML structure:
* <foo a="foo.a">
* <bar>abc</bar>
* <fum fee="xyz">def</fum>
* </foo>
* The path "foo/bar" refers to the value "abc".
* The path "foo/fum" refers to the value "def".
* If this form is used, there may be only #text or #comment nodes in the node. All #text nodes will be
* concatenated and then stripped of whitespace at the beginning and the end.
* The path "foo/fum.fee" refers to the value "xyz".
* The path "foo.a" refers to the value "foo.a".
*
* When using getMultiple, any node or attribute name can be substituted with "*" to get all elements:
* The path "foo/*" returns both the value "abc" and "def".
* @author Mathias Ricken
*/
public class XMLConfig {
/** Newline string.
*/
public static final String NL = System.getProperty("line.separator");
/** XML document.
*/
private Document _document;
/** XMLConfig to delegate to, or null.
*/
private XMLConfig _parent = null;
/** Node where this XMLConfig starts if delegation is used, or null.
*/
private Node _startNode = null;
/** Creates an empty configuration.
*/
public XMLConfig() {
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
try {
DocumentBuilder builder = factory.newDocumentBuilder();
_document = builder.newDocument(); // Create from whole cloth
// NOTE: not 1.4 compatible -- _document.setXmlStandalone(true);
}
catch(ParserConfigurationException e) {
e.printStackTrace();
}
}
/** Creates a configuration from an input stream.
* @param is input stream
*/
public XMLConfig(InputStream is) {
init(new InputSource(is));
}
/** Creates a configuration from a reader.
* @param r reader
*/
public XMLConfig(Reader r) {
init(new InputSource(r));
}
/** Creates a configuration that is a part of another configuration, starting at the specified node.
* @param parent the configuration that contains this part
* @param node the node in the parent configuration where this part starts
*/
public XMLConfig(XMLConfig parent, Node node) {
if ((parent==null) || (node==null)) { throw new XMLConfigException("Error in ctor: parent or node is null"); }
_parent = parent;
_startNode = node;
_document = null;
}
/** Initialize this XML configuration.
* @param is the XML input source
*/
private void init(InputSource is) {
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = null;
try {
builder = factory.newDocumentBuilder();
_document = builder.parse(is);
// NOTE: not 1.4 compatible -- _document.setXmlStandalone(true);
}
catch(Exception e) {
throw new XMLConfigException("Error in ctor", e);
}
_document.normalize();
}
/** Creates a configuration from a file.
* @param f file
*/
public XMLConfig(File f) {
try {
init(new InputSource(new FileInputStream(f)));
}
catch(FileNotFoundException e) {
throw new XMLConfigException("Error in ctor", e);
}
}
/** Creates a configuration from a file name.
* @param filename file name
*/
public XMLConfig(String filename) {
try {
init(new InputSource(new FileInputStream(filename)));
}
catch(FileNotFoundException e) {
throw new XMLConfigException("Error in ctor", e);
}
}
public boolean isDelegated() { return (_parent!=null); }
/** Saves configuration to an output stream
* @param os output stream
*/
public void save(OutputStream os) {
if (isDelegated()) { _parent.save(os); return; }
// Prepare the DOM document for writing
Source source = new DOMSource(_document);
/*
// Prepare the output file
Result result = new StreamResult(os);
*/
// Write the DOM document to the file
try {
TransformerFactory tf = TransformerFactory.newInstance();
tf.setAttribute("indent-number", Integer.valueOf(2));
Transformer t = tf.newTransformer();
t.setOutputProperty(OutputKeys.INDENT, "yes");
t.transform(source, new StreamResult(new OutputStreamWriter(os, "utf-8")));
/*
Transformer xformer = TransformerFactory.newInstance().newTransformer();
xformer.setOutputProperty(OutputKeys.INDENT, "yes");
xformer.transform(source, result);
*/
}
catch(TransformerException e) {
throw new XMLConfigException("Error in save", e);
}
catch(UnsupportedEncodingException e) {
throw new XMLConfigException("Error in save", e);
}
}
/** Saves configuration to a file.
* @param f file
*/
public void save(File f) {
if (isDelegated()) { _parent.save(f); return; }
FileOutputStream fos = null;
try {
fos = new FileOutputStream(f);
save(fos);
}
catch(FileNotFoundException e) {
throw new XMLConfigException("Error in save", e);
}
finally {
try {
if (fos!=null) fos.close();
}
catch(IOException ioe) { /* ignore exception when closing */ }
}
}
/** Saves configuration to a file specified by a file name.
* @param filename file name
*/
public void save(String filename) {
save(new File(filename));
}
// ----- String ------
/** Returns the value as specified by the DOM path.
* @param path DOM path
* @return value.
*/
public String get(String path) {
List<String> r = getMultiple(path);
if (r.size()!=1) throw new XMLConfigException("Number of results != 1");
return r.get(0);
}
/** Returns the value as specified by the DOM path.
* @param path DOM path
* @param root node where the search should start
* @return value.
*/
public String get(String path, Node root) {
List<String> r = getMultiple(path, root);
if (r.size()!=1) throw new XMLConfigException("Number of results != 1");
return r.get(0);
}
/** Returns the value as specified by the DOM path, or the default value if the value could not be found.
* @param path DOM path
* @param defaultVal default value in case value is not in DOM
* @return value.
*/
public String get(String path, String defaultVal) {
try {
return get(path);
}
catch(XMLConfigException e) {
return defaultVal;
}
}
/** Returns the value as specified by the DOM path, or the default value if the value could not be found.
* @param path DOM path
* @param root node where the search should start
* @param defaultVal default value in case value is not in DOM
* @return value.
*/
public String get(String path, Node root, String defaultVal) {
try {
return get(path, root);
}
catch(XMLConfigException e) {
return defaultVal;
}
}
// ----- Integer ------
/** Returns the value as specified by the DOM path.
* @param path DOM path
* @return value.
* @throws IllegalArgumentException
*/
public int getInt(String path) {
List<String> r = getMultiple(path);
if (r.size()!=1) throw new XMLConfigException("Number of results != 1");
try {
return Integer.valueOf(r.get(0));
}
catch(NumberFormatException nfe) { throw new IllegalArgumentException("Not an integer value.", nfe); }
}
/** Returns the value as specified by the DOM path.
* @param path DOM path
* @param root node where the search should start
* @return value.
* @throws IllegalArgumentException
*/
public int getInt(String path, Node root) {
List<String> r = getMultiple(path, root);
if (r.size()!=1) throw new XMLConfigException("Number of results != 1");
try {
return Integer.valueOf(r.get(0));
}
catch(NumberFormatException nfe) { throw new IllegalArgumentException("Not an integer value.", nfe); }
}
/** Returns the value as specified by the DOM path, or the default value if the value could not be found.
* @param path DOM path
* @param defaultVal default value in case value is not in DOM
* @return value.
* @throws IllegalArgumentException
*/
public int getInt(String path, int defaultVal) {
try {
return getInt(path);
}
catch(XMLConfigException e) {
return defaultVal;
}
}
/** Returns the value as specified by the DOM path, or the default value if the value could not be found.
* @param path DOM path
* @param root node where the search should start
* @param defaultVal default value in case value is not in DOM
* @return value.
* @throws IllegalArgumentException
*/
public int getInt(String path, Node root, int defaultVal) {
try {
return getInt(path, root);
}
catch(XMLConfigException e) {
return defaultVal;
}
}
// ----- Boolean ------
/** Returns the value as specified by the DOM path.
* @param path DOM path
* @return value.
* @throws IllegalArgumentException
*/
public boolean getBool(String path) {
List<String> r = getMultiple(path);
if (r.size()!=1) throw new XMLConfigException("Number of results != 1");
String s = r.get(0).toLowerCase().trim();
if ((s.equals("true")) ||
(s.equals("yes")) ||
(s.equals("on"))) return true;
if ((s.equals("false")) ||
(s.equals("no")) ||
(s.equals("off"))) return false;
throw new IllegalArgumentException("Not a Boolean vlaue.");
}
/** Returns the value as specified by the DOM path.
* @param path DOM path
* @param root node where the search should start
* @return value.
* @throws IllegalArgumentException
*/
public boolean getBool(String path, Node root) {
List<String> r = getMultiple(path, root);
if (r.size()!=1) throw new XMLConfigException("Number of results != 1");
String s = r.get(0).toLowerCase().trim();
if ((s.equals("true")) ||
(s.equals("yes")) ||
(s.equals("on"))) return true;
if ((s.equals("false")) ||
(s.equals("no")) ||
(s.equals("off"))) return false;
throw new IllegalArgumentException("Not a Boolean vlaue.");
}
/** Returns the value as specified by the DOM path, or the default value if the value could not be found.
* @param path DOM path
* @param defaultVal default value in case value is not in DOM
* @return value.
* @throws IllegalArgumentException
*/
public boolean getBool(String path, boolean defaultVal) {
try {
return getBool(path);
}
catch(XMLConfigException e) {
return defaultVal;
}
}
/** Returns the value as specified by the DOM path, or the default value if the value could not be found.
* @param path DOM path
* @param root node where the search should start
* @param defaultVal default value in case value is not in DOM
* @return value.
* @throws IllegalArgumentException
*/
public boolean getBool(String path, Node root, boolean defaultVal) {
try {
return getBool(path, root);
}
catch(XMLConfigException e) {
return defaultVal;
}
}
// ----- Other -----
/** Returns the value as specified by the DOM path.
* @param path DOM path
* @return list of values.
*/
public List<String> getMultiple(String path) {
if (isDelegated()) { return getMultiple(path, _startNode); }
return getMultiple(path, _document);
}
/** Returns the value as specified by the DOM path.
* @param path DOM path
* @param root node where the search should start
* @return list of values.
*/
public List<String> getMultiple(String path, Node root) {
List<Node> accum = getNodes(path, root);
List<String> strings = new LinkedList<String>();
for(Node n: accum) {
if (n instanceof Attr) {
strings.add(n.getNodeValue());
}
else {
Node child;
String acc = "";
child = n.getFirstChild();
while(child!=null) {
if (child.getNodeName().equals("#text")) {
acc += " " + child.getNodeValue();
}
else if (child.getNodeName().equals("#comment")) {
// ignore
}
else {
throw new XMLConfigException("Node "+n.getNodeName()+" contained node "+child.getNodeName()+", but should only contain #text and #comment.");
}
child = child.getNextSibling();
}
strings.add(acc.trim());
}
}
return strings;
}
/** Returns the nodes as specified by the DOM path.
* @param path DOM path
* @return list of nodes.
*/
public List<Node> getNodes(String path) {
if (isDelegated()) { return getNodes(path, _startNode); }
return getNodes(path, _document);
}
/** Returns the nodes as specified by the DOM path.
* @param path DOM path
* @param root node where the search should start
* @return list of nodes.
*/
public List<Node> getNodes(String path, Node root) {
List<Node> accum = new LinkedList<Node>();
getMultipleHelper(path, root, accum, false);
return accum;
}
/** Returns the value as specified by the DOM path.
* @param path DOM path
* @param n node where the search begins
* @param accum accumulator
* @param dotRead whether a dot has been read
*/
private void getMultipleHelper(String path, Node n, List<Node> accum, boolean dotRead) {
int dotPos = path.indexOf('.');
boolean initialDot = (dotPos==0);
if ((path.length()>0) && (dotPos == -1) && (!path.endsWith("/"))) {
path = path + "/";
}
int slashPos = path.indexOf('/');
if(dotPos != -1 && path.indexOf('.', dotPos+1) != -1)
throw new XMLConfigException("An attribute cannot have subparts (foo.bar.fum and foo.bar/fum not allowed)");
if(dotPos != -1 && path.indexOf('/', dotPos+1) != -1)
throw new XMLConfigException("An attribute cannot have subparts (foo.bar.fum and foo.bar/fum not allowed)");
if (((slashPos > -1) || (dotPos > -1)) && !dotRead || initialDot) {
String nodeName;
if ((slashPos > -1) && ((dotPos == -1) || (slashPos < dotPos))) {
nodeName = path.substring(0, slashPos);
path = path.substring(slashPos+1);
}
else {
if (slashPos > -1) {
throw new XMLConfigException("An attribute cannot have subparts (foo.bar.fum and foo.bar/fum not allowed)");
}
if (!initialDot) {
nodeName = path.substring(0, dotPos);
path = path.substring(dotPos+1);
dotRead = true;
}
else {
path = path.substring(1);
getMultipleAddAttributesHelper(path, n, accum);
return;
}
}
Node child = n.getFirstChild();
if (nodeName.equals("*")) {
while(child!=null) {
if (!child.getNodeName().equals("#text") && !child.getNodeName().equals("#comment")) {
if (dotRead) {
getMultipleAddAttributesHelper(path, child, accum);
}
else {
getMultipleHelper(path, child, accum, false);
}
}
child = child.getNextSibling();
}
return;
}
else {
while(child!=null) {
if (child.getNodeName().equals(nodeName)) {
// found
if (dotRead) {
getMultipleAddAttributesHelper(path, child, accum);
}
else {
getMultipleHelper(path, child, accum, false);
}
}
child = child.getNextSibling();
}
return;
}
}
else {
accum.add(n);
}
}
private void getMultipleAddAttributesHelper(String path, Node n, List<Node> accum) {
if ((path.indexOf('.') > -1) || (path.indexOf('/') > -1)) {
throw new XMLConfigException("An attribute cannot have subparts (foo.bar.fum and foo.bar/fum not allowed)");
}
NamedNodeMap attrMap = n.getAttributes();
if (path.equals("*")) {
for(int i=0; i<attrMap.getLength(); ++i) {
Node attr = attrMap.item(i);
accum.add(attr);
}
}
else {
Node attr = attrMap.getNamedItem(path);
if (attr!=null) {
accum.add(attr);
}
}
}
/** Set the value of the node or attribute specified by the DOM path.
* @param path DOM path
* @param value node or attribute value
* @return the node that was created, or the parent node of the attribute if it was an attribute
*/
public Node set(String path, String value) {
if (isDelegated()) { return set(path, value, _startNode, true); }
return set(path, value, _document, true);
}
/** Set the value of the node or attribute specified by the DOM path.
* @param path DOM path
* @param value node or attribute value
* @param overwrite whether to overwrite (true) or add (false)
* @return the node that was created, or the parent node of the attribute if it was an attribute
*/
public Node set(String path, String value, boolean overwrite) {
if (isDelegated()) { return set(path, value, _startNode, overwrite); }
return set(path, value, _document, overwrite);
}
/** Set the value of the node or attribute specified by the DOM path.
* @param path DOM path
* @param value node or attribute value
* @param n node where the search should start
* @param overwrite whether to overwrite (true) or add (false) -- only applies for last node!
* @return the node that was created, or the parent node of the attribute if it was an attribute
*/
public Node set(String path, String value, Node n, boolean overwrite) {
if (isDelegated()) { return _parent.set(path, value, n, overwrite); }
int dotPos = path.lastIndexOf('.');
Node node;
if (dotPos==0) {
node = n;
}
else {
node = createNode(path, n, overwrite);
}
if (dotPos>=0) {
Element e = (Element)node;
e.setAttribute(path.substring(dotPos+1),value);
}
else {
node.appendChild(_document.createTextNode(value));
}
return node;
}
/** Create the node specified by the DOM path.
* @param path DOM path
* @return the node that was created, or the parent node of the attribute if it was an attribute
*/
public Node createNode(String path) {
if (isDelegated()) { return createNode(path, _startNode, true); }
return createNode(path, _document, true);
}
/** Create the node specified by the DOM path.
* @param path DOM path
* @param n node where the search should start, or null for the root
* @return the node that was created, or the parent node of the attribute if it was an attribute
*/
public Node createNode(String path, Node n) {
return createNode(path, n, true);
}
/** Create the node specified by the DOM path.
* @param path DOM path
* @param n node where the search should start, or null for the root
* @param overwrite whether to overwrite (true) or add (false) -- only applies for last node!
* @return the node that was created, or the parent node of the attribute if it was an attribute
*/
public Node createNode(String path, Node n, boolean overwrite) {
if (isDelegated()) { return _parent.createNode(path, n, overwrite); }
if (n==null) { n = _document; }
while(path.indexOf('/') > -1) {
Node child = null;
String nodeName = path.substring(0, path.indexOf('/'));
path = path.substring(path.indexOf('/')+1);
child = n.getFirstChild();
while(child!=null) {
if (child.getNodeName().equals(nodeName)) {
// found
n = child;
break;
}
child = child.getNextSibling();
}
if (child==null) {
// not found
child = _document.createElement(nodeName);
n.appendChild(child);
n = child;
}
}
String nodeName;
if (path.indexOf('.') > -1) {
nodeName = path.substring(0, path.indexOf('.'));
}
else {
if (path.length()==0) {
throw new XMLConfigException("Cannot set node with empty name");
}
nodeName = path;
}
Node child = null;
if (nodeName.length()>0) {
if (overwrite) {
child = n.getFirstChild();
while(child!=null) {
if (child.getNodeName().equals(nodeName)) {
// found
n = child;
break;
}
child = child.getNextSibling();
}
if (child==null) {
child = _document.createElement(nodeName);
n.appendChild(child);
n = child;
}
}
else {
child = _document.createElement(nodeName);
n.appendChild(child);
n = child;
}
}
if (path.indexOf('.') > -1) {
if (!(n instanceof Element)) {
throw new XMLConfigException("Node "+n.getNodeName()+" should be an element so it can contain attributes");
}
return n;
}
else {
if (overwrite) {
child = n.getFirstChild();
// remove all children
while(child!=null) {
Node temp = child.getNextSibling();
n.removeChild(child);
child = temp;
}
return n;
}
else {
return child;
}
}
}
/** Returns a string representation of the object.
* @return a string representation of the object.
*/
public String toString() {
ByteArrayOutputStream os = new ByteArrayOutputStream();
save(os);
return os.toString();
}
/** Return the path of a node as it is used in XMLConfig.
* @param n node
* @return path
*/
public static String getNodePath(Node n) {
if (n==null) { return ""; }
String path = "";
while(n.getParentNode()!=null) {
path = n.getNodeName()+"/"+path;
n = n.getParentNode();
}
return path.substring(0,path.length()-1);
}
/** Exception in XMLConfig methods.
*/
public static class XMLConfigException extends RuntimeException {
public XMLConfigException() {
super();
}
public XMLConfigException(String message) {
super(message);
}
public XMLConfigException(String message, Throwable cause) {
super(message, cause);
}
public XMLConfigException(Throwable cause) {
super(cause);
}
}
}
]]>