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Java解析XML（二）、DOM
XML資源文件請見https://blog.csdn.net/xyang81/article/details/7247169
package xml;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.util.ArrayList;
import java.util.List;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Result;
import javax.xml.transform.Source;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import model.Book;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import util.DateUtils;
/**
* 使用DOM讀寫XML
* @author 楊信
*
*/
public class DomHelper {
private static DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
/**
* 使用DOM解析XML
* @param is XML文件輸入流
* @return 解析後的數據
*/
public static List<Book> domReader(InputStream is) {
List<Book> books = null;
try {
DocumentBuilder db = dbf.newDocumentBuilder();
Document document = db.parse(is);
Element rootElement = document.getDocumentElement();
NodeList nodes = rootElement.getElementsByTagName("book");
if (nodes != null && nodes.getLength() > 0) {
books = new ArrayList<Book>();
for(int i = 0; i < nodes.getLength(); i++) {
/*//獲得節點方式1
Node node = nodes.item(i);
book.setIsbn(node.getAttributes().item(0).getNodeValue()); //獲得book節點ISBN屬性的值
//獲得book節點下的所有子節點
NodeList bookChildList = node.getChildNodes();*/
//獲得節點方式2
Book book = new Book();
Element bookElement = (Element) nodes.item(i);
book.setIsbn(bookElement.getAttribute("isbn")); //獲得book節點ISBN屬性的值
NodeList bookChildList = bookElement.getChildNodes();
for(int j = 0; j < bookChildList.getLength(); j++) {
Node childNode = bookChildList.item(j);
if (childNode.getNodeType() == Node.ELEMENT_NODE) { //判斷當前節點類型,是否為一個元素節點.(節點類型分:Element和Text節點.)
String nodeName = childNode.getNodeName();
String nodeValue = childNode.getTextContent();
if ("name".equals(nodeName)) {
book.setName(nodeValue);
} else if ("author".equals(nodeName)) {
book.setAuthor(nodeValue);
} else if ("publishing".equals(nodeName)) {
book.setPublishing(nodeValue);
} else if ("pubdate".equals(nodeName)) {
book.setPubdate(DateUtils.string2Date("yyyy-mm-dd", nodeValue));
} else if ("price".equals(nodeName)) {
book.setPrice(Double.parseDouble(nodeValue));
}
}
}
books.add(book);
}
}
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return books;
}
/**
* 使用dom寫xml文件
* @param books 數據
* @param outfile xml文件保存位置
*/
public static void domWriter(List<Book> books,File outfile) {
Document doc = null;
try {
DocumentBuilder db = dbf.newDocumentBuilder();
doc = db.newDocument();
Element booksElement = doc.createElement("books");
for (Book book : books) {
//創建一本圖書
Element bookElement = doc.createElement("book");
//設置圖片的編號
bookElement.setAttribute("isbn", book.getIsbn());
//書名
Element nameElement = doc.createElement("name");
nameElement.setTextContent(book.getName());
bookElement.appendChild(nameElement);
//作者
Element authorElement = doc.createElement("author");
authorElement.setTextContent(book.getAuthor());
bookElement.appendChild(authorElement);
//出版社
Element publishingElement = doc.createElement("publishing");
publishingElement.setTextContent(book.getPublishing());
bookElement.appendChild(publishingElement);
//出版日期
Element pubdateElement = doc.createElement("pubdate");
pubdateElement.setTextContent(DateUtils.date2String("yyyy-mm-dd", book.getPubdate()));
bookElement.appendChild(pubdateElement);
//價格
Element priceElement = doc.createElement("price");
priceElement.setTextContent(String.valueOf(book.getPrice()));
bookElement.appendChild(priceElement);
//將每本書添加到根節點中
booksElement.appendChild(bookElement);
}
doc.appendChild(booksElement);
//將數據生成xml文件
FileOutputStream fos = new FileOutputStream(outfile);
OutputStreamWriter outwriter = new OutputStreamWriter(fos);
callWriteXmlFile(doc, outwriter, "gb2312");
outwriter.close();
fos.close();
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 定入xml文件
* @param doc xml文檔對象
* @param w 寫xml文件的字符流對象
* @param encoding xml編碼
*/
public static void callWriteXmlFile(Document doc, Writer w, String encoding) {
try {
Source source = new DOMSource(doc);
Result result = new StreamResult(w);
Transformer xformer = TransformerFactory.newInstance().newTransformer();
xformer.setOutputProperty(OutputKeys.ENCODING, encoding);
xformer.transform(source, result);
} catch (TransformerConfigurationException e) {
e.printStackTrace();
} catch (TransformerException e) {
e.printStackTrace();
}
}
}
最後更新：2017-04-02 22:16:20