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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 doc = 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 doc = 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);
}
}
