使用java自带的xml解析器解析xml

//------------------ main point ---------------------
javax.xml.parsers.SAXParserFactory
public static void main(String[] args)
{
//cdu 存放结果的对象
CS3drawUnit cdu=new CS3drawUnit(); SAXParserFactory factory = SAXParserFactory.newInstance(); SAXParser parser;
try {
parser = factory.newSAXParser(); /* // 方式一
InputStream is=new ByteArrayInputStream(strxml.getBytes("UTF-8"));
parser.parse(is, new Apphandler(cdu));
*/ // 方式二
parser.parse(new File("cs3.xml"),new Apphandler(cdu));
}
catch (ParserConfigurationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SAXException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} // 存放结果的实体
//------------------CS3drawUnit bean---------------------
public class CS3drawUnit { //可以有多个 fields，因为太多我省略了好多
private String XWallThickness=""; public String getXWallThickness() {
return XWallThickness;
}
public void setXWallThickness(String xWallThickness) {
XWallThickness = xWallThickness;
} } // 这就是处理类handler
//------------------Apphandler ---------------------
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler; public class Apphandler extends DefaultHandler { /*
<field>
<name>Type / tubes in face</name>
<value>A (1/2" OD) / 16</value>
</field> */ Unit u=null;
//内部类 为了在characters方法中调用，使代码显的清晰
public class Unit{ private String xname="";
private String xvalue="";
private String xmodelNo ="";
private String xahTag =""; public String getXahTag() {
return xahTag;
}
public void setXahTag(String xahTag) {
this.xahTag = xahTag;
}
public String getXname() {
return xname;
}
public void setXname(String xname) {
this.xname = xname;
}
public String getXvalue() {
return xvalue;
}
public void setXvalue(String xvalue) {
this.xvalue = xvalue;
}
public String getxmodelNo() {
return xmodelNo;
}
public void setxmodelNo(String xmodelNo) {
this.xmodelNo = xmodelNo;
} }
CS3drawUnit cdu=null; private final int xname_STATE = 1;
private final int xvalue_STATE = 2;
private final int xmodelNo_STATE = 3;
private final int xahTag_STATE = 4; private int currentState; public Apphandler(CS3drawUnit cdu)
{
this.cdu=cdu;
currentState=0;
u=new Unit();
} //获取解析结果，可以再处理，此处把结果再加工，set到cdu实例中返回
///@Override
public void endElement(String uri, String localName, String qName)
throws SAXException { if(qName.equals("modelNo")&& u!= null){
cdu.setXModelNo(u.getxmodelNo());
}
if(qName.equals("ahTag")&& u!= null){
cdu.setXAhTag(u.getXahTag());
} } public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {
// TODO Auto-generated method stub
//System.out.println("qName:"+qName);
if (qName.equals("field")){
u=new Unit();
return;
} if (qName.equals("name")){
currentState = xname_STATE;
return ;
} if (qName.equals("value")){
currentState = xvalue_STATE;
return ;
}
if (qName.equals("modelNo")){
currentState = xmodelNo_STATE;
return ;
} if (qName.equals("ahTag")){
currentState = xahTag_STATE;
return ;
}
} public void characters(char[] ch, int start, int length) throws SAXException { //length这个值在某些情况下，会被裁断（莫名其妙），估计是bug，遇到过一回，
//所以我在后来不让它解析出错时的字段，改用Dom解析。
String theString = new String(ch, start, length); switch(currentState)
{
case xname_STATE:
u.setXname(theString);
currentState = 0;
break; case xvalue_STATE:
u.setXvalue(theString);
currentState = 0;
break;
case xmodelNo_STATE:
u.setxmodelNo(theString);
currentState = 0;
break;
case xahTag_STATE:
u.setXahTag(theString);
currentState = 0;
break;
}
} }