一个读取xml文件内容的类
package project.util.xml;
import java.io.*;
import java.util.*;
import javax.servlet.http.*;
import org.apache.log4j.*;
import org.jdom.*;
import org.jdom.input.*;
/**
* <p>Title: <font color="steelblue" size="10">读取xml文件信息</font></p>
* <p>Description: <font color="steelblue">从XML配置文件中获得配置信息。excerpt form jdom。</font></p>
* <p>Copyright: <font color="steelblue">Copyright (c) 2004</font></p>
* <p>Company: <font color="steelblue">Harmonious</font></p>
* @author <font color="steelblue">TZL</font>
* @version <font color="steelblue">1.0</font>
*/
public class XMLReader {
/*
#设置根的输出配置，格式为 "info [2004-05-01 22:35:30] [name]logname(b.c) [line] 86 msg-->log信息"
log4j.rootLogger=DEBUG, rootAppender
log4j.appender.rootAppender=org.apache.log4j.RollingFileAppender
log4j.appender.rootAppender.File=e:/MapXtremeSmpl.log
log4j.appender.rootAppender.MaxFileSize=1000KB
log4j.appender.rootAppender.layout=org.apache.log4j.PatternLayout
log4j.appender.rootAppender.layout.ConversionPattern=%-5p [%d{yyyy-mm-dd HH:mm:ss}] [name] %c{2} [line] %L msg--> %m%n
*/
static public Logger log = Logger.getLogger(XMLReader.class);
protected Element m_RootElement = null;
protected String m_webAppPath = null;
/**
* <font color="orange">构造函数。</font>
* @param xmlFile <font color="steelblue">要读取的配置文件的绝对路径。</font>
*/
public XMLReader(String xmlFile) {
m_webAppPath = null;
try {
PatternLayout layout = new PatternLayout("%-5p %d{yyyy-MM-dd HH:mm:ss} [name] %c{2} [line] %L [msg] %m%n");
ConsoleAppender appender = new ConsoleAppender(/*new SimpleLayout(),*/layout, "System.err");
log.addAppender(appender);
SAXBuilder builder = new SAXBuilder();
document．nbspdoc = null;
doc = builder.build(new FileInputStream(xmlFile));
m_RootElement = doc.getRootElement();
}
catch (IOException ex) {
log.error("XMLReader构造时出现IO错误:" + ex.toString());
}
catch (JDOMException ex1) {
log.error("XMLReader构造时分析XML文件出错:" + ex1.toString());
}
catch (Exception ex) {
log.error("XMLReader 构造出错:" + ex.toString());
}
}
/**
* <font color="orange">构造函数。配置文件必须指定为发布的应用的根目录下的/XmlConfig/Config.xml。</font>
* @param servletObj <font color="steelblue">随便一个HttpServlet对象。</font>
*/
public XMLReader(HttpServlet servletObj) {
m_webAppPath = servletObj.getServletContext().getRealPath("/");
String configFileName = m_webAppPath + "XmlConfig/Config.xml";
try {
PatternLayout layout = new PatternLayout("%-5p %d{yyyy-MM-dd HH:mm:ss} [name] %c{2} [line] %L [msg] %m%n");
ConsoleAppender appender = new ConsoleAppender( /*new SimpleLayout(),*/layout, "System.err");
log.addAppender(appender);
SAXBuilder builder = new SAXBuilder();
document．nbspdoc = null;
doc = builder.build(new FileInputStream(configFileName));
m_RootElement = doc.getRootElement();
}
catch (IOException ex) {
log.error("XMLReader构造时出现IO错误（/XmlConfig/Config.xml）:" + ex.toString());
}
catch (JDOMException ex1) {
log.error("XMLReader构造时分析XML文件出错（/XmlConfig/Config.xml）:" + ex1.toString());
}
catch (Exception ex) {
log.error("XMLReader构造出错（/XmlConfig/Config.xml）:" + ex.toString());
}
}
/**
* <font color="orange">web应用发布在web服务器的绝对路径根目录，最后已经有目录分割符。</font>
* @return <font color="tomato">返回web应用发布在web服务器的绝对路径的根目录。</font>
*/
public String getWebAppPath() {
return m_webAppPath;
}
/**
* <font color="orange">从配置文件中获得配置信息。</font>
* @param key <font color="steelblue">要获取的配置名称。</font>
* @param curRootName <font color="steelblue">查找的起始节点名称，如果为null从根开始查找。</font>
* @return <font color="tomato">配置的字符串。</font>
*/
public String getElementvalue(String curRootName, String key) {
String value = null;
Element curRoot = getElement(null, curRootName);
if (null == curRoot) {
curRoot = m_RootElement;
}
Element keyNode = getElement(curRoot, key);
if (null != keyNode) {
value = keyNode.getTextTrim();
}
return value;
}
/**
* <font color="orange">根据名字获得节点。广度遍历，递归调用。</font>
* @param nodeName <font color="steelblue">节点的名字。</font>
* @param curRoot <font color="steelblue"> 从开始查找的起始节点，如果为null从根开始查找。</font>
* @return <font color="tomato">返回从指定节点下找到的第一个节点。如果没有返回null。</font>
*/
private Element getElement(Element curRoot, String nodeName) {
Element retElement = null;
if (null == nodeName)
return m_RootElement;
if (null == curRoot) {
curRoot = m_RootElement;
}
if (null != curRoot) {
retElement = curRoot.getChild(nodeName);
if (null == retElement) {
List nestElements = curRoot.getChildren();
Iterator iterator = nestElements.iterator();
while (iterator.hasNext() && null == retElement) {
retElement = getElement( (Element) iterator.next(), nodeName);
}
}
}
return retElement;
}
/**
* <font color="orange">获得指定节点的属性。</font>
* @param elementName <font color="steelblue">节点的名称。</font>
* @param attName <font color="steelblue">要获得的属性的名称。</font>
* @return <font color="tomato">要查找的属性的值。</font>
*/
public String getElementAtrribute(String elementName, String attName)
{
Element el = getElement(null, elementName);
if (null == el)
return null;
return el.getAttributevalue(attName);
}
}