根据xml的标签解析文件的Demo

package xmlExtractor;

import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

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

public class SAXHandler extends DefaultHandler {
int bookIndex = 0;
private List<Book> bookList = new ArrayList<Book>();
private Book book = null;
private String value = null;

//用来标志解析开始
@Override
public void startDocument() throws SAXException {

System.out.println("解析开始");
}

//用来标志解析结束
@Override
public void endDocument() throws SAXException {
System.out.println("解析结束");
}

//用来遍历元素
//开始标签
@Override
public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {

if (qName.equals("book")) {
bookIndex++;
book = new Book();
System.out.println("============================第" + bookIndex + "本书开始了=========================");
//已知book下属性元素的名称
//System.out.println(attributes.getValue("id"));
for (int i = 0; i < attributes.getLength(); i++) {
String name = attributes.getQName(i);
if (name.equals("id")) {
book.setId(attributes.getValue(i));
} else if (name.equals("class")) {
book.setClassName(attributes.getValue(i));
}
book.setId(attributes.getValue(i));
//System.out.println(name);
System.out.println("第" + bookIndex + "本书的" + attributes.getQName(i) + "是:" + attributes.getValue(i)/*attributes.getValue(Qname)*/);
}
} else if (!qName.equals("bookStore")) {
System.out.print("第" + bookIndex + "本书的" + qName + "是:");
}

}

//遍历标签内的内容
@Override
public void characters(char[] ch, int start, int length) throws SAXException {
value = new String(ch, start, length);
//如果标签下没有内容，如bookstore与book之间就没有内容，将不打印
if (!value.trim().equals("")) {
System.out.println(value);

}

}

//遍历元素的结束标签
@Override
public void endElement(String uri, String localName, String qName) throws SAXException {
if (qName.equals("book")) {
bookList.add(book);
book = null;
System.out.println("============================第" + bookIndex + "本书结束了=========================");
} else if (qName.equals("name")) {
book.setName(value);
} else if (qName.equals("author")) {
book.setAuthor(value);
} else if (qName.equals("year")) {
book.setYear(value);
}

}

public List<Book> getBookList() {
return bookList;
}

}