DOM add/update/delete XML (CURD)

Get Document

/**
* Getting documents
* 1. Obtain the instance factory
* 2. Get the parser
* 3. Obtain the document
*/

 

Add node

/**
* 1. Obtain the root node.
* 2. Create a node (set attributes)
* 3. Create a subnode ()
* 4. Add to the root node
*/

Update node

/**
* Update XML
* 1. Obtain all nodes
* 2. Obtain each book
* 3. Obtain the ID
* 4. Update
** 1. Update the id
** 2. Update a subnode
*/

Delete a node

/**
* Delete XML
* 1. Obtain all nodes
* 2. Obtain each book
* 3. Obtain the ID
* 4. Delete
*/

Save XML

/**
* Save xml
* 1. Obtain the persistent object instance factory
* 2. Obtain a persistent object
* 3. Save the memory data to the disk.
** Source ---- encapsulate the document object to the Source
** Result ---- encapsulate the file path to Result
* 4. Save
*/

 

1 public static void main (String [] args) throws Exception {2 // get document 3 Document document = getDocument (); 4 // update xml 5 // UpdateXml (document ); 6 7 // add XML 8 9 // AddXML (document); 10 11 12 // delete xml 13 // DeleXML (document ); 14 15 16 17/** 18 * Save 19 */20 Save (document ); 21 22} 23 24/** 25*1. Obtain the root node 26*2. Create a node (set attributes) 27*3. Create a subnode () 28*4. Add to root node 29 */30 private static void AddXML (Document document) {31 Element rootElement = document. getDocumentElement (); 32 33 Element newElement = document. createElement ("book"); 34 35 newElement. setAttribute ("id", "b003"); 36 37 Element PriceElement = document. createElement ("title"); 38 PriceElement. setTextContent ("30"); 39 PriceElement. setAttribute ("unit", "￥"); 40 newElement. appendChild (PriceElement); 41 42 rootElement. appendChild (newElement ); 43} 44 45/** 46 * delete XML 47*1. Get all nodes 48*2. Get 49*3. Get ID 50*4. Delete 51 */52. 53 private static void DeleXML (Document document) {54 NodeList nodeList = document. getElementsByTagName ("book"); 55 for (int I = 0; I <nodeList. getLength (); I ++) {56 Node chilNode = nodeList. item (I); 57 String id = (Element) chilNode ). getAttribute ("id"); 58 if ("b001 ". equals (id) 59 {60 Node parentNode = chilNode. getParentNode (); 61 parentNode. removeChild (chilNode ); 62} 63} 64} 65 66/** 67 * update XML 68*1. Get all nodes 69*2. Get 70*3. Get ID 71*4. Update 72 ** 1. Update id 73 ** 2. Update subnode 74 */75 private static void UpdateXml (Document document) {76 NodeList nodeList = document. getElementsByTagName ("book"); 77 for (int I = 0; I <nodeList. getLength (); I ++) {78 Node node = nodeList. item (I); 79 Element element = (Element) node; 80 String id = element. getAttribute ("id"); 81 if ("b001 ". equals (id) 82 {83 // element. setAttribute ("id", "booooo"); // update the id value 84 NodeList childNode = element. getElementsByTagName ("title"); 85 Element childElement = (Element) childNode. item (0); // childNode. getLength () = 1 86 childElement. setTextContent ("Java core technology "); 87} 88} 89} 90 91/** 92 * save xml 93*1. Get the persistence object instance factory 94*2. Get the persistence object 95*3. Save the memory data disk 96 ** Source ---- encapsulate document object to Source 97 ** Result ---- encapsulate file path to Result 98*4, Save 99 */100 private static void Save (Document document) 101 throws Exception {102 TransformerFactory factory = TransformerFactory. newInstance (); 103 Transformer transformer = factory. newTransformer (); 104 Source xmlSource = new DOMSource (document); 105 javax. xml. transform. result outputTarget = new StreamResult ("books. jaxp. xml "); 106 107 transformer. transform (xmlSource, outputTarget); 108 109 System. out. println ("done "); 110} 111 112/** 113 * get Document 114*1. Get instance factory 115*2. Get parser 116*3. Get document117 */118 119 private static Document getDocument () throws ParserConfigurationException, 120 SAXException, IOException {121 DocumentBuilderFactory factory = DocumentBuilderFactory. newInstance (); 122 DocumentBuilder builder = factory. newDocumentBuilder (); 123 Document document = builder. parse ("books. xml "); 124 return document; 125}

 

DOM add/update/delete XML (CURD)