abstractparser.java

稿件名称：基于JAVA的JNDI技术和反射机制 稿件作者：段谟意 源代码名称：WEB-INF 调试环境：Win XP；Tomcat, JVM:JDK 1.5.2

package ddd.com.parse;
import javax.xml.parsers.*;
import javax.servlet.*;
import java.io.*;
import org.w3c.dom.*;
import org.xml.sax.*;

public abstract class AbstractParser
{
	protected Element root;
	public void init(ServletContext sct,String xmlSource)
	{
		try
		{
			String filename=sct.getInitParameter(xmlSource);
			InputStream is=sct.getResourceAsStream(filename);
			DocumentBuilderFactory dbf=DocumentBuilderFactory.newInstance();
			dbf.setIgnoringElementContentWhitespace(true);
			DocumentBuilder db=dbf.newDocumentBuilder();
			Document doc=db.parse(is);
			root=doc.getDocumentElement();
			is.close();
		}
		catch(Exception e)
		{
			sct.log("init:",e);
		}
	}
	protected String getElementValue(Node parent,String child)
	{
		String value=null;
		if(parent.getNodeType()==Node.ELEMENT_NODE && parent.hasChildNodes())
		{
			Node childNode=((Element)parent).getElementsByTagName(child).item(0);
			if(childNode.getNodeType()==Node.ELEMENT_NODE && childNode.hasChildNodes())
			{
				Node textNode=childNode.getChildNodes().item(0);
				if(textNode.getNodeType()==Node.TEXT_NODE)
					value=textNode.getNodeValue();
			}
		}
		return value;
	}
	protected NodeList getElements(Node parent,String child)
	{
		NodeList nodeList=null;
		if(parent.getNodeType()==Node.ELEMENT_NODE && parent.hasChildNodes())
			nodeList=((Element)parent).getElementsByTagName(child);
		return nodeList;
	}
	protected String getProperty(Node element,String attname)
	{
		String value=null;
		if(element.hasAttributes())
		{
			NamedNodeMap attrs=element.getAttributes();
			Node attNode=attrs.getNamedItem(attname);
			value=attNode.getNodeValue();
		}
		return value;
	}
	protected void clearup()
	{
		root=null;
	}
}