一、XML解析

通过继承org.xml.sax.helpers.DefaultHandler类，覆写characters(),startDocument(),startElement(),endElement()方法实现读取

characters() --------读取结点中的字段值

startDocument()------------进行读取的初始化

startElement()-------------为每次读取初始化

endElement()------------实现读取功能

以下是实现解析功能的源代码：

package org.hjw.service;

import java.util.ArrayList;
import java.util.List;

import org.hjw.model.Product;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

public class XML2Product extends DefaultHandler {
private Product product;
private List products;
StringBuffer buffer = new StringBuffer();

public List getProducts() {
return products;
}

@Override
public void characters(char[] ch, int start, int length)
throws SAXException {
buffer.append(ch, start, length);
super.characters(ch, start, length);
}

@Override
public void startDocument() throws SAXException {
products = new ArrayList();
}

@Override
public void startElement(String uri, String localName, String qName,
Attributes attributes) throws SAXException {
if (localName.equals("product")) {
product = new Product();
}
super.startElement(uri, localName, qName, attributes);
}

@Override
public void endElement(String uri, String localName, String qName)
throws SAXException {
if (localName.equals("product")) {
products.add(product);
} else if (localName.equals("id")) {
product.setId(Integer.parseInt(buffer.toString().trim()));
buffer.setLength(0);
} else if (localName.equals("name")) {
product.setName(buffer.toString().trim());
buffer.setLength(0);
} else if (localName.equals("price")) {
product.setPrice(Float.parseFloat(buffer.toString().trim()));
buffer.setLength(0);
}
super.endElement(uri, localName, qName);
}

}

然后只需在主函数中：

打开输入流，通过工具类分析xml文件即可获得一个ArrayList类型的集合，然后实现解析功能。