package com.mlongbo.jfinal.common;
import org.dom4j.CDATA;
import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.Node;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.*;
import java.util.*;
/**
* @author malongbo
*/
public class XmlProperty {
private static final Logger Log = LoggerFactory.getLogger(XmlProperty.class);
private static long lastModified = 0L;
private static final Object lock = new Object();
private File file;
private Document document;
private Map<String,String> propertyCache = new HashMap<String, String>();
/**
* Creates a new XMLPropertiesTest object.
*
* @param fileName the full path the file that properties should be read from
* and written to.
* @throws java.io.IOException if an error occurs loading the properties.
*/
public XmlProperty(String fileName) throws IOException {
this(new File(fileName));
}
/**
* Creates a new XMLPropertiesTest object.
*
* @param file the file that properties should be read from and written to.
* @throws java.io.IOException if an error occurs loading the properties.
*/
public XmlProperty(File file) throws IOException {
this.file = file;
if (!file.exists()) {
// Attempt to recover from this error case by seeing if the
// tmp file exists. It's possible that the rename of the
// tmp file failed the last time Jive was running,
// but that it exists now.
File tempFile;
tempFile = new File(file.getParentFile(), file.getName() + ".tmp");
if (tempFile.exists()) {
Log.error("WARNING: " + file.getName() + " was not found, but temp file from " +
"previous write operation was. Attempting automatic recovery." +
" Please check file for data consistency.");
tempFile.renameTo(file);
}
// There isn't a possible way to recover from the file not
// being there, so throw an error.
else {
throw new FileNotFoundException("XML properties file does not exist: "
+ file.getName());
}
}
// Check read and write privs.
if (!file.canRead()) {
throw new IOException("XML properties file must be readable: " + file.getName());
}
if (!file.canWrite()) {
throw new IOException("XML properties file must be writable: " + file.getName());
}
FileReader reader = new FileReader(file);
lastModified = file.lastModified();
buildDoc(reader);
}
/**
* Builds the document XML model up based the given reader of XML data.
* @param in the input stream used to build the xml document
* @throws java.io.IOException thrown when an error occurs reading the input stream.
*/
private void buildDoc(Reader in) throws IOException {
try {
SAXReader xmlReader = new SAXReader();
xmlReader.setEncoding("UTF-8");
document = xmlReader.read(in);
propertyCache.clear();
}
catch (Exception e) {
Log.error("Error reading XML properties", e);
throw new IOException(e.getMessage());
}
finally {
if (in != null) {
in.close();
}
}
}
/**
* 检查文件是否有更新*
*/
private void reCheck() {
if (lastModified < file.lastModified()) {
synchronized (lock) {
if (lastModified < file.lastModified()) {
lastModified = file.lastModified();
try {
buildDoc(new FileReader(file));
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
}
/**
* Returns the value of the specified property.
*
* @param name the name of the property to get.
* @return the value of the specified property.
*/
public synchronized String getProperty(String name) {
String value = propertyCache.get(name);
if (value != null) {
return value;
}
String[] propName = parsePropertyName(name);
// Search for this property by traversing down the XML heirarchy.
Element element = document.getRootElement();
for (String aPropName : propName) {
element = element.element(aPropName);
if (element == null) {
// This node doesn't match this part of the property name which
// indicates this property doesn't exist so return null.
return null;
}
}
// At this point, we found a matching property, so return its value.
// Empty strings are returned as null.
value = element.getTextTrim();
if ("".equals(value)) {
return null;
}
else {
// Add to cache so that getting property next time is fast.
propertyCache.put(name, value);
return value;
}
}
/**
* Return all values who's path matches the given property
* name as a String array, or an empty array if the if there
* are no children. This allows you to retrieve several values
* with the same property name. For example, consider the
* XML file entry:
* <pre>
* <foo>
* <bar>
* <prop>some value</prop>
* <prop>other value</prop>
* <prop>last value</prop>
* </bar>
* </foo>
* </pre>
* If you call getProperties("foo.bar.prop") will return a string array containing
* {"some value", "other value", "last value"}.
*
* @param name the name of the property to retrieve
* @return all child property values for the given node name.
*/
public String[] getProperties(String name) {
String[] propName = parsePropertyName(name);
// Search for this property by traversing down the XML heirarchy,
// stopping one short.
Element element = document.getRootElement();
for (int i = 0; i < propName.length - 1; i++) {
element = element.element(propName[i]);
if (element == null) {
// This node doesn't match this part of the property name which
// indicates this property doesn't exist so return empty array.
return new String[]{};
}
}
// We found matching property, return names of children.
Iterator iter = element.elementIterator(propName[propName.length - 1]);
List<String> props = new ArrayList<String>();
String value;
while (iter.hasNext()) {
// Empty strings are skipped.
value = ((Element)iter.next()).getTextTrim();
if (!"".equals(value)) {
props.add(value);
}
}
String[] childrenNames = new String[props.size()];
return props.toArray(childrenNames);
}
/**
* Return all values who's path matches the given property
* name as a String array, or an empty array if the if there
* are no children. This allows you to retrieve several values
* with the same property name. For example, consider the
* XML file entry:
* <pre>
* <foo>
* <bar>
* <prop>some value</prop>
* <prop>other value</prop>
* <prop>last value</prop>
* </bar>
* </foo>
* </pre>
* If you call getProperties("foo.bar.prop") will return a string array containing
* {"some value", "other value", "last value"}.
*
* @param name the name of the property to retrieve
* @return all child property values for the given node name.
*/
public Iterator getChildProperties(String name) {
String[] propName = parsePropertyName(name);
// Search for this property by traversing down the XML heirarchy,
// stopping one short.
Element element = document.getRootElement();
for (int i = 0; i < propName.length - 1; i++) {
element = element.element(propName[i]);
if (element == null) {
// This node doesn't match this part of the property name which
// indicates this property doesn't exist so return empty array.
return Collections.EMPTY_LIST.iterator();
}
}
// We found matching property, return values of the children.
Iterator iter = element.elementIterator(propName[propName.length - 1]);
ArrayList<String> props = new ArrayList<String>();
while (iter.hasNext()) {
props.add(((Element)iter.next()).getText());
}
return props.iterator();
}
/**
* Returns the value of the attribute of the given property name or <tt>null</tt>
* if it doesn't exist. Note, this
*
* @param name the property name to lookup - ie, "foo.bar"
* @param attribute the name of the attribute, ie "id"
* @return the value of the attribute of the given property or <tt>null</tt> if
* it doesn't exist.
*/
public String getAttribute(String name, String attribute) {
if (name == null || attribute == null) {
return null;
}
String[] propName = parsePropertyName(name);
// Search for this property by traversing down the XML heirarchy.
Element element = document.getRootElement();
for (String child : propName) {
element = element.element(child);
if (element == null) {
// This node doesn't match this part of the property name which
// indicates this property doesn't exist so return empty array.
break;
}
}
if (element != null) {
// Get its attribute values
return element.attributeValue(attribute);
}
return null;
}
/**
* Return all children property names of a parent property as a String array,
* or an empty array if the if there are no children. For example, given
* the properties <tt>X.Y.A</tt>, <tt>X.Y.B</tt>, and <tt>X.Y.C</tt>, then
* the child properties of <tt>X.Y</tt> are <tt>A</tt>, <tt>B</tt>, and
* <tt>C</tt>.
*
* @param parent the name of the parent property.
* @return all child property values for the given parent.
*/
public String[] getChildrenProperties(String parent) {
String[] propName = parsePropertyName(parent);
// Search for this property by traversing down the XML heirarchy.
Element element = document.getRootElement();
for (String aPropName : propName) {
element = element.element(aPropName);
if (element == null) {
// This node doesn't match this part of the property name which
// indicates this property doesn't exist so return empty array.
return new String[]{};
}
}
// We found matching property, return names of children.
List children = element.elements();
int childCount = children.size();
String[] childrenNames = new String[childCount];
for (int i = 0; i < childCount; i++) {
childrenNames[i] = ((Element)children.get(i)).getName();
}
return childrenNames;
}
/**
* Returns an array representation of the given Jive property. Jive
* properties are always in the format "prop.name.is.this" which would be
* represented as an array of four Strings.
*
* @param name the name of the Jive property.
* @return an array representation of the given Jive property.
*/
private String[] parsePropertyName(String name) {
List<String> propName = new ArrayList<String>(5);
// Use a StringTokenizer to tokenize the property name.
StringTokenizer tokenizer = new StringTokenizer(name, ".");
while (tokenizer.hasMoreTokens()) {
propName.add(tokenizer.nextToken());
}
return propName.toArray(new String[propName.size()]);
}
private Element getElement(String name) {
String[] propName = parsePropertyName(name);
// Search for this property by traversing down the XML heirarchy.
Element element = document.getRootElement();
for (int i = 0; i < propName.length; i++) {
element = element.element(propName[i]);
// Can't find the property so return.
if (element == null) {
break;
}
}
return element;
}
/**
* Saves the properties to disk as an XML document. A temporary file is
* used during the writing process for maximum safety.
*/
private synchronized void saveProperties() {
boolean error = false;
// Write data out to a temporary file first.
File tempFile = null;
Writer writer = null;
try {
tempFile = new File(file.getParentFile(), file.getName() + ".tmp");
writer = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(tempFile), "UTF-8"));
OutputFormat prettyPrinter = OutputFormat.createPrettyPrint();
XMLWriter xmlWriter = new XMLWriter(writer, prettyPrinter);
xmlWriter.write(document);
}
catch (Exception e) {
Log.error(e.getMessage(), e);
// There were errors so abort replacing the old property file.
error = true;
}
finally {
if (writer != null) {
try {
writer.close();
}
catch (IOException e1) {
Log.error(e1.getMessage(), e1);
error = true;
}
}
}
// No errors occured, so delete the main file.
if (!error) {
// Delete the old file so we can replace it.
if (!file.delete()) {
Log.error("Error deleting property file: " + file.getAbsolutePath());
return;
}
// Copy new contents to the file.
try {
copy(tempFile, file);
}
catch (Exception e) {
Log.error(e.getMessage(), e);
// There were errors so abort replacing the old property file.
error = true;
}
// If no errors, delete the temp file.
if (!error) {
tempFile.delete();
}
}
}
/**
* Copies the inFile to the outFile.
*
* @param inFile The file to copy from
* @param outFile The file to copy to
* @throws java.io.IOException If there was a problem making the copy
*/
private static void copy(File inFile, File outFile) throws IOException {
FileInputStream fin = null;
FileOutputStream fout = null;
try {
fin = new FileInputStream(inFile);
fout = new FileOutputStream(outFile);
copy(fin, fout);
}
finally {
try {
if (fin != null) fin.close();
}
catch (IOException e) {
// do nothing
}
try {
if (fout != null) fout.close();
}
catch (IOException e) {
// do nothing
}
}
}
/**
* Copies data from an input stream to an output stream
*
* @param in the stream to copy data from.
* @param out the stream to copy data to.
* @throws java.io.IOException if there's trouble during the copy.
*/
private static void copy(InputStream in, OutputStream out) throws IOException {
// Do not allow other threads to intrude on streams during copy.
synchronized (in) {
synchronized (out) {
byte[] buffer = new byte[256];
while (true) {
int bytesRead = in.read(buffer);
if (bytesRead == -1) break;
out.write(buffer, 0, bytesRead);
}
}
}
}
public void destroy() {
document = null;
file = null;
propertyCache.clear();
propertyCache = null;
}
}