/*
* 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.
*/
package org.apache.empire.xml;
import java.io.Closeable;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.InvocationTargetException;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.apache.commons.beanutils.BeanUtils;
import org.apache.empire.commons.ObjectUtils;
import org.apache.empire.commons.StringUtils;
import org.apache.empire.exceptions.FileParseException;
import org.apache.empire.exceptions.FileReadException;
import org.apache.empire.exceptions.InternalException;
import org.apache.empire.exceptions.InvalidArgumentException;
import org.apache.empire.exceptions.ItemNotFoundException;
import org.apache.empire.exceptions.ObjectNotValidException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
/**
* <PRE>
* This class manages the configuration of a Java Bean by an xml configuration file.
* It also supports configuration of Log4J.
* </PRE>
*
*/
public class XMLConfiguration
{
private static final Logger log = LoggerFactory.getLogger(XMLConfiguration.class);
private Element configRootNode = null;
/**
* Initialize the configuration.
*
* @param filename the file
* @param fromResource will read from the classpath if true
*
* @return true on success
*/
public void init(String filename, boolean fromResource)
{
// Read the properties file
readConfiguration(filename, fromResource);
}
/**
* returns the configuration root element or null if init() has not been called.
* @return the configuration root element
*/
public Element getRootNode()
{
return configRootNode;
}
/**
* Reads the configuration file and parses the XML Configuration.
*/
protected void readConfiguration(String fileName, boolean fromResource)
{
FileReader reader = null;
InputStream inputStream = null;
try
{
DocumentBuilder docBuilder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
Document doc = null;
if (fromResource)
{ // Open Resource
log.info("reading resource file: " + fileName);
inputStream = getClass().getClassLoader().getResourceAsStream(fileName);
// Parse File
doc = docBuilder.parse(inputStream);
}
else
{ // Open File
log.info("reading configuration file: " + fileName);
reader = new FileReader(fileName);
// Parse File
doc = docBuilder.parse(new InputSource(reader));
}
// Get Root Element
configRootNode = doc.getDocumentElement();
} catch (FileNotFoundException e)
{
log.error("Configuration file {} not found!", fileName, e);
throw new FileReadException(fileName, e);
} catch (IOException e)
{
log.error("Error reading configuration file {}", fileName, e);
throw new FileReadException(fileName, e);
} catch (SAXException e)
{
log.error("Invalid XML in configuration file {}", fileName, e);
throw new FileParseException(fileName, e);
} catch (ParserConfigurationException e)
{
log.error("ParserConfigurationException: {}", e.getMessage(), e);
throw new InternalException(e);
} finally
{
close(reader);
close(inputStream);
}
}
/**
* reads all properties from a given properties node and applies them to the given bean
* @param bean the bean to which to apply the configuration
* @param propertiesNodeName the name of the properties node below the root element
* @return true of successful or false otherwise
*/
public void readProperties(Object bean, String... propertiesNodeNames)
{
// Check state
if (configRootNode == null)
throw new ObjectNotValidException(this);
// Check arguments
if (bean == null)
throw new InvalidArgumentException("bean", bean);
Element propertiesNode = configRootNode;
for(String nodeName : propertiesNodeNames)
{
if (StringUtils.isEmpty(nodeName))
throw new InvalidArgumentException("propertiesNodeNames", null);
// Get configuration node
propertiesNode = XMLUtil.findFirstChild(propertiesNode, nodeName);
if (propertiesNode == null)
{ // Configuration
log.error("Property-Node {} has not been found.", nodeName);
throw new ItemNotFoundException(nodeName);
}
}
// read the properties
readProperties(bean, propertiesNode);
}
/**
* reads all properties from a given properties node and applies them to the given bean
* @param bean the bean to which to apply the configuration
* @param propertiesNode the properties node
* @return true of successful or false otherwise
*/
public void readProperties(Object bean, Element propertiesNode)
{
// Check arguments
if (propertiesNode == null)
throw new InvalidArgumentException("propertiesNode", propertiesNode);
if (bean == null)
throw new InvalidArgumentException("bean", bean);
// apply configuration
log.info("reading bean properties from node: {}", propertiesNode.getNodeName());
NodeList nodeList = propertiesNode.getChildNodes();
for (int i = 0; i < nodeList.getLength(); i++)
{
Node item = nodeList.item(i);
if (item.getNodeType() != Node.ELEMENT_NODE)
continue;
// Get the Text and set the Property
setPropertyValue(bean, item);
}
}
protected void setPropertyValue(Object bean, Node item)
{
// Get the Text and set the Property
String name = item.getNodeName();
try
{
String newValue = XMLUtil.getElementText(item);
BeanUtils.setProperty(bean, name, newValue);
Object value = BeanUtils.getProperty(bean, name);
if (ObjectUtils.compareEqual(newValue, value))
{
log.info("Configuration property '{}' set to \"{}\"", name, newValue);
}
else
{
log.error("Failed to set property '{}'. Value is \"{}\"", name, value);
}
} catch (IllegalAccessException e)
{
log.error("Access to Property {} denied.", name);
} catch (InvocationTargetException e)
{
log.error("Unable to set Property {}", name);
} catch (NoSuchMethodException e)
{
log.error("Property '{}' not found in {}", name, bean.getClass().getName());
}
}
private void close(final Closeable closeable) {
if (closeable != null)
{
try
{
closeable.close();
}
catch(IOException e)
{
log.debug(e.getMessage());
}
}
}
}