讀取XML文檔：

讀寫XML文檔主要依賴于org.dom4j.io包，有DOMReader和SAXReader兩種方式。因為利用了相同的接口，它們的調用方式是一樣的。

public static Document load(String filename) { Document document = null; try { SAXReader saxReader = new SAXReader(); document = saxReader.read(new File(filename)); // 讀取XML文件,獲得document對象 } catch (Exception ex) { ex.printStackTrace(); } return document; } public static Document load(URL url) { Document document = null; try { SAXReader saxReader = new SAXReader(); document = saxReader.read(url); // 讀取XML文件,獲得document對象 } catch (Exception ex) { ex.printStackTrace(); } return document; }

//讀取指定的xml文件之后返回一個Document對象，這個對象代表了整個XML文檔，用于各種Dom運算。執照XML文件頭所定義的編碼來轉換。

獲取根節點

根節點是xml分析的開始，任何xml分析工作都需要從根開始

Xml xml = new Xml(); Document dom = xml.load(path + "/" + file); Element root = dom.getRootElement();

新增一個節點以及其下的子節點與數據

Element menuElement = root.addElement("menu"); Element engNameElement = menuElement.addElement("engName"); engNameElement.setText(catNameEn); Element chiNameElement = menuElement.addElement("chiName"); chiNameElement.setText(catName);

寫入XML文件

注意文件操作的包裝類是亂碼的根源

public static boolean doc2XmlFile(Document document, String filename) { boolean flag = true; try { XMLWriter writer = new XMLWriter(new OutputStreamWriter( new FileOutputStream(filename), "UTF-8")); writer.write(document); writer.close(); } catch (Exception ex) { flag = false; ex.printStackTrace(); } System.out.println(flag); return flag; }

Dom4j通過XMLWriter將Document對象表示的XML樹寫入指定的文件，并使用OutputFormat格式對象指定寫入的風格和編碼方法。調用OutputFormat.createPrettyPrint()方法可以獲得一個默認的pretty print風格的格式對象。對OutputFormat對象調用setEncoding()方法可以指定XML文件的編碼方法。

public void writeTo(OutputStream out, String encoding) throws UnsupportedEncodingException, IOException { OutputFormat format = OutputFormat.createPrettyPrint(); format.setEncoding("gb2312"); XMLWriter writer = new XMLWriter(System.out, format); writer.write(doc); writer.flush(); return; }

遍歷xml節點

???????對Document對象調用getRootElement()方法可以返回代表根節點的Element對象。擁有了一個Element對象后，可以對該對象調用elementIterator()方法獲得它的子節點的Element對象們的一個迭代器。使用(Element)iterator.next()方法遍歷一個iterator并把每個取出的元素轉化為Element類型。

public boolean isOnly(String catNameEn, HttpServletRequest request, String xml) { boolean flag = true; String path = request.getRealPath(""); Document doc = load(path + "/" + xml); Element root = doc.getRootElement(); for (Iterator i = root.elementIterator(); i.hasNext();) { Element el = (Element) i.next(); if (catNameEn.equals(el.elementTextTrim("engName"))) { flag = false; break; } } return flag; }

創建xml文件

public static void main(String args[]) { String fileName = "c:/text.xml"; Document document = DocumentHelper.createDocument();// 建立document對象，用來操作xml文件 Element booksElement = document.addElement("books");// 建立根節點 booksElement.addComment("This is a test for dom4j ");// 加入一行注釋 Element bookElement = booksElement.addElement("book");// 添加一個book節點 bookElement.addAttribute("show", "yes");// 添加屬性內容 Element titleElement = bookElement.addElement("title");// 添加文本節點 titleElement.setText("ajax in action");// 添加文本內容 try { XMLWriter writer = new XMLWriter(new FileWriter(new File(fileName))); writer.write(document) //寫入writer.close(); } catch (Exception e) { e.printStackTrace(); } }

修改節點屬性

public static void modifyXMLFile() { String oldStr = "c:/text.xml"; String newStr = "c:/text1.xml"; Document document = null; //修改節點的屬性 try { SAXReader saxReader = new SAXReader(); // 用來讀取xml文檔 document = saxReader.read(new File(oldStr)); // 讀取xml文檔 List list = document.selectNodes("/books/book/@show");// 用xpath查找節點book的屬性 Iterator iter = list.iterator(); while (iter.hasNext()) { Attribute attribute = (Attribute) iter.next(); if (attribute.getValue().equals("yes")) attribute.setValue("no"); } } catch (Exception e) { e.printStackTrace(); } //修改節點的內容 try { SAXReader saxReader = new SAXReader(); // 用來讀取xml文檔 document = saxReader.read(new File(oldStr)); // 讀取xml文檔 List list = document.selectNodes("/books/book/title");// 用xpath查找節點book的內容 Iterator iter = list.iterator(); while (iter.hasNext()) { Element element = (Element) iter.next(); element.setText("xxx");// 設置相應的內容 } } catch (Exception e) { e.printStackTrace(); } try { XMLWriter writer = new XMLWriter(new FileWriter(new File(newStr))); writer.write(document); writer.close(); } catch (Exception ex) { ex.printStackTrace(); } }

刪除節點

public static void removeNode() { String oldStr = "c:/text.xml"; String newStr = "c:/text1.xml"; Document document = null; try { SAXReader saxReader = new SAXReader();// 用來讀取xml文檔 document = saxReader.read(new File(oldStr));// 讀取xml文檔 List list = document.selectNodes("/books/book");// 用xpath查找對象 Iterator iter = list.iterator(); while (iter.hasNext()) { Element bookElement = (Element) iter.next(); // 創建迭代器，用來查找要刪除的節點,迭代器相當于指針，指向book下所有的title節點 Iterator iterator = bookElement.elementIterator("title"); while (iterator.hasNext()) { Element titleElement = (Element) iterator.next(); if (titleElement.getText().equals("ajax in action")) { bookElement.remove(titleElement); } } } } catch (Exception e) { e.printStackTrace(); } try { XMLWriter writer = new XMLWriter(new FileWriter(new File(newStr))); writer.write(document); writer.close(); } catch (Exception ex) { ex.printStackTrace(); } }

總結

以上是生活随笔為你收集整理的Dom4j完整教程~XML文档简单操作的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。