XML文件--使用DOM4J示例

Posted 2020-08-26 Penney_

• 其他依赖字段/方法

private List<Book> bookList = new LinkedList<Book>();
	public List<Book> getBookList(String file) {
		parseXML(file);
		return this.bookList;
	}

• 获取DocumentBuilder(文件解析器)
  

/**
	 * 解析XML文件
	 * * @param file
	 */
	private void parseXML(String file) {
		// 创建book临时变量
		Book book = null;
		// 1.创建SAXReader对象
		SAXReader reader = new SAXReader();
		// 2.1 创建输入流
		InputStreamReader input = null;
		try {
			// 2.2 实例化输入流，并指定编码
			input = new InputStreamReader(new FileInputStream(file), "utf-8");
			// 3.加载XML文件到 document
			Document document = reader.read(input);
			// 4.获取根节点
			Element rootElement = document.getRootElement();
			// 5.根据根节点获取子节点迭代器，并遍历
			Iterator bookIter = rootElement.elementIterator();
			while (bookIter.hasNext()) {
				// 初始化book对象
				book = new Book();
				// 声明子节点对象
				Element bookEle = (Element) bookIter.next();
				// 如果子节点为book
				if (bookEle.getName().equals("book")) {
					// 6.获取book节点的属性迭代器，并遍历
					Iterator eleIter = bookEle.attributeIterator();
					while (eleIter.hasNext()) {
						// 声明属性对象
						Attribute attr = (Attribute) eleIter.next();
						if (attr.getName().equals("id")) {
							book.setId(Integer.valueOf(attr.getValue()));
						}
					}
					// 7.获取book节点的子节点迭代器，并遍历
					Iterator childIter = bookEle.elementIterator();
					while (childIter.hasNext()) {
						// 声明book子节点对象
						Element child = (Element) childIter.next();
						// 判断并为book对象赋值
						switch (child.getName()) {
						case "title":
							book.setTitle(child.getText());
							break;
						case "author":
							book.setAuthor(child.getText());
							break;
						case "price":
							book.setPrice(Double.valueOf(child.getText()));
							break;
						case "year":
							book.setYear(child.getText());
							break;
						case "language":
							book.setLanguage(child.getText());
							break;
						default:
							System.out.println("未知属性！");
						}
					}
					// 向书籍列表添加书籍对象
					bookList.add(book);
				}
			}
		} catch (UnsupportedEncodingException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (DocumentException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			if (null != input) {
				try {
					input.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		}
	}

• 生成XML文件
  

/**
	 * 创建XML文件，保存book列表
	 * @param bookList
	 * @param fileName
	 * @param encoding
	 */
	private void createXML1(List<Book> bookList, String fileName,
			String encoding) {
		// 1.创建Document文件
		Document document = DocumentHelper.createDocument();
		// 2.创建root节点
		Element root = document.addElement("bookstore");
		// 3.创建book节点
		for (Book book : bookList) {
			Element ebook = root.addElement("book");
			// 4.1为book节点添加属性
			ebook.addAttribute("id", String.valueOf(book.getId()));
			// 4.2为book增加子节点，并设置文本值
			Element eTitle = ebook.addElement("title");
			eTitle.addCDATA(book.getTitle());
			Element eAuthor = ebook.addElement("author");
			eAuthor.setText(book.getAuthor());
			Element eYear = ebook.addElement("year");
			eYear.setText(book.getYear());
			Element ePrice = ebook.addElement("ePrice");
			ePrice.setText(String.valueOf(book.getPrice()));
			Element eLanguage = ebook.addElement("language");
			eLanguage.setText(book.getLanguage());
		}
		// 5.声明输出流
		OutputStream output = null;
		XMLWriter writer = null;
		// 6.设置输出的XML格式
		OutputFormat format = OutputFormat.createPrettyPrint();
		// 7.设置XML文档编码
		format.setEncoding(encoding);
		try {
			// 8.实例化输出流
			output = new FileOutputStream(fileName);
			// 9.实例化XML输出流，加载XML格式及设置
			writer = new XMLWriter(output, format);
			// 10.向硬盘写入XML
			writer.write(document);
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (UnsupportedEncodingException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			if (null != output) {
				try {
					output.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
			if (null != writer) {
				try {
					writer.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		}
	}

• 创建RSS文件

/**
	 * 创建RSS文件
	 * 
	 * @param fileName
	 */
	private void createXML(String fileName) {
		// 1.创建document对象，代表XML文件
		Document document = DocumentHelper.createDocument();
		// 2.创建根节点
		Element rss = document.addElement("rss");
		// 3.为rss节点添加version属性（版本）
		rss.addAttribute("version", "2");
		// 3.1生成子节点及节点内容
		Element channel = rss.addElement("channel");
		// 3.2生成内容
		Element title = channel.addElement("title");
		title.setText("<![CDATA[国内最新新闻]]>");
		// 4.创建xml输出流
		File file = new File(fileName);
		XMLWriter writer = null;
		try {
			// 5.设置xml格式
			OutputFormat format = OutputFormat.createPrettyPrint();
			// 设置xml编码
			format.setEncoding("GBK");
			writer = new XMLWriter(new FileOutputStream(file), format);
			// 设置是否转义，默认为true（转义）
			writer.setEscapeText(false);
			// 6.将XML文件写到硬盘
			writer.write(document);
		} catch (UnsupportedEncodingException | FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			if (null != writer) {
				try {
					writer.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		}
	}