在Java中读取写入XML文件(DEMO_004)[Java编程]

1.假如要将读取的XML文件,再写入别的的一个新XML文件中,首先必须新建一个和要读取相对应的beans类,通过set办法填充数据,get办法获得数据.

2.在读取XML文件的时刻,需求用到ArrayList调集来存储每次从原XML文件里面读取的数据,在写入新的XML文件的时刻,也要通过ArrayList调集获得要遍历的次数,同时将数据写入到新的xml文件中

3.具体代码以下:

public static void main(String[] args) {

try {

String url = "book.xml";

ArrayList list = getBookList(url);

//写入一个新的xml文件

FileWriter fw = new FileWriter("newbook.xml");

fw.write("<?xml version="1.0" encoding="UTF-8"?>");

fw.write("n<books>");

for (int i = 0; i < list.size(); i++) {

BookBean book = (BookBean)list.get(i);

fw.write("n<book>n");

if(book.getTitle()!=null){

fw.write("<title>");

fw.write(book.getTitle());

fw.write("</title>n");

}

if(book.getAuthor()!=null){

fw.write("<author>");

fw.write(book.getAuthor());

fw.write("</author>n");

}

if(book.getPrice()!=null){

fw.write("<price>");

fw.write(book.getPrice());

fw.write("</price>n");

}

fw.write("</book>n");

}

fw.write("</books>");

fw.close();

} catch (Exception e) {

System.out.println(e.getMessage());

}

}

//获得从一个xml文件中读取的数据,并将其保存在ArrayList中

public static ArrayList getBookList(String url){

ArrayList list = new ArrayList();

try{

DocumentBuilder db = DocumentBuilderFactory.newInstance().newDocumentBuilder();

Document doc = db.parse(url);

NodeList nodeList = doc.getElementsByTagName("book");

for (int i = 0; i < nodeList.getLength(); i++) {

String title = doc.getElementsByTagName("title").item(i).getFirstChild().getNodeValue();

String author = doc.getElementsByTagName("author").item(i).getFirstChild().getNodeValue();

String price = doc.getElementsByTagName("price").item(i).getFirstChild().getNodeValue();

BookBean book = new BookBean();

book.setTitle(title);

book.setAuthor(author);

book.setPrice(price);

list.add(book);

}

}catch(Exception e){

System.out.println(e.getMessage());

}

return list;

}

}

假如你想把这个代码看懂的话,我倡议你,先把怎样从XML读取的数据的看懂!