java(12)--xml之dom方式的增删改查

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import java.io.FileOutputStream;import javax.xml.parsers.DocumentBuilder;import javax.xml.parsers.DocumentBuilderFactory;import javax.xml.transform.Transformer;import javax.xml.transform.TransformerFactory;import javax.xml.transform.dom.DOMSource;import javax.xml.transform.stream.StreamResult;import org.junit.Test;import org.w3c.dom.Document;import org.w3c.dom.Element;import org.w3c.dom.Node;import org.w3c.dom.NodeList;public class domofcurd {    // 使用dom方式对xml文件进行crud 增删改查    @Test    // 读取xml文档中：<书名>Java网络编程精解</书名> 节点中的值    public void read1() throws Exception {        // 创建解析工厂        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();        // 创建构造器        DocumentBuilder builder = factory.newDocumentBuilder();        // 得到xml文件        Document document = builder.parse("src/book.xml");        NodeList list = document.getElementsByTagName("书名");        Node item = list.item(1);// 选取第二个        String content = item.getTextContent();        System.out.println(content);    }    // 得到xml文档中的所有标签    @Test    public void read2() throws Exception {        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();        DocumentBuilder builder = factory.newDocumentBuilder();        Document document = builder.parse("src/book.xml");        // 得到根节点        Node rootNode = document.getElementsByTagName("书架").item(0);        list(rootNode);    }    public void list(Node node) {        if (node instanceof Element) {            System.out.println(node.getNodeName());        }        NodeList list = node.getChildNodes();        for (int i = 0; i < list.getLength(); i++) {            Node childNode = list.item(i);            list(childNode);        }    }    // 得到xml文档中标签属性的值：<书名 name="xxxx">Head First Java</书名>    @Test    public void read3() throws Exception {        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();        DocumentBuilder buider = factory.newDocumentBuilder();        Document document = buider.parse("src/book.xml");        Element bookname = (Element) document.getElementsByTagName("书名")                .item(0);        String value = bookname.getAttribute("name");        System.out.println(value);    }    // 向xml文档中添加节点：<售价>59.00元</售价>    @Test    public void add() throws Exception {        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();        DocumentBuilder buider = factory.newDocumentBuilder();        Document document = buider.parse("src/book.xml");        // 创建节点        Element price = document.createElement("售价");        price.setTextContent("59.00元");        // 将节点挂在第一本书上        Element booknode = (Element) document.getElementsByTagName("书").item(0);        booknode.appendChild(price);        // 把更新后内存写回到xml文档        TransformerFactory tffactory = TransformerFactory.newInstance();        Transformer transformer = tffactory.newTransformer();        transformer.transform(new DOMSource(document), new StreamResult(                new FileOutputStream("src/book.xml")));    }    // 向xml文档中指定位置上添加节点：<售价>59.00元</售价>    @Test    public void add2() throws Exception {        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();        DocumentBuilder builder = factory.newDocumentBuilder();        Document document = builder.parse("src/book.xml");        // 创建节点        Element price = document.createElement("售价");        price.setTextContent("59.00元");        // 得到参考节点        Element refNode = (Element) document.getElementsByTagName("售价").item(0);        // 得到要插入节点的父节点---book节点        Element book = (Element) document.getElementsByTagName("书").item(0);        // 往book节点的指定位置插入子节点        book.insertBefore(price, refNode);        // 把更新后内存写回到xml文档        TransformerFactory tffactory = TransformerFactory.newInstance();        Transformer tf = tffactory.newTransformer();        tf.transform(new DOMSource(document), new StreamResult(                new FileOutputStream("src/book.xml")));    }    // 向xml文档节点上添加属性：<书名>Java网络编程精解</书名> 上添加name=“xxx”属性    @Test    public void addAttr() throws Exception {        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();        DocumentBuilder builder = factory.newDocumentBuilder();        Document document = builder.parse("src/book.xml");        Element bookname = (Element) document.getElementsByTagName("书名")                .item(1);        bookname.setAttribute("name", "xxxxx");        // 把更新后内存写回到xml文档        TransformerFactory tffactory = TransformerFactory.newInstance();        Transformer tf = tffactory.newTransformer();        tf.transform(new DOMSource(document), new StreamResult(                new FileOutputStream("src/book.xml")));    }    // 删除元素    @Test    public void delete1() throws Exception {        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();        DocumentBuilder builder = factory.newDocumentBuilder();        Document document = builder.parse("src/book.xml");        // 得到要删除的结点        Element e = (Element) document.getElementsByTagName("售价").item(0);        // 得到要删除的结点的父节点        Element book = (Element) document.getElementsByTagName("书").item(0);        // 从父节点上移除子节点        book.removeChild(e);        // 把更新后内存写回到xml文档        TransformerFactory tffactory = TransformerFactory.newInstance();        Transformer tf = tffactory.newTransformer();        tf.transform(new DOMSource(document), new StreamResult(                new FileOutputStream("src/book.xml")));    }    // 删除整个xml    @Test    public void delete2() throws Exception {        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();        DocumentBuilder builder = factory.newDocumentBuilder();        Document document = builder.parse("src/book.xml");        // 得到要删除的结点        Element element = (Element) document.getElementsByTagName("售价").item(0);        element.getParentNode().getParentNode().getParentNode()                .removeChild(element.getParentNode().getParentNode());        // 把更新后内存写回到xml文档        TransformerFactory tffactory = TransformerFactory.newInstance();        Transformer tf = tffactory.newTransformer();        tf.transform(new DOMSource(document), new StreamResult(                new FileOutputStream("src/book.xml")));    }    // 更新售价    @Test    public void update() throws Exception {        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();        DocumentBuilder builder = factory.newDocumentBuilder();        Document document = builder.parse("src/book.xml");        Element e = (Element) document.getElementsByTagName("售价").item(0);        e.setTextContent("109元");        // 把更新后内存写回到xml文档        TransformerFactory tffactory = TransformerFactory.newInstance();        Transformer tf = tffactory.newTransformer();        tf.transform(new DOMSource(document), new StreamResult(                new FileOutputStream("src/book.xml")));    }}
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