本篇文章为大家展示了如何在java中操作xml,内容简明扼要并且容易理解,绝对能使你眼前一亮,通过这篇文章的详细介绍希望你能有所收获。
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一丶常用方法
主要有3个方面, 1读取xml文件, 2使用xpath根据指定路径获取某一节点数据 3, xml和java bean的转换
XmlUtils.java
public class XmlUtils { // -------------------------------------- public static Document createXml(){ return XmlUtil.createXml(); } // -------------------------------------- /** * 读取xml文档 * @param xmlInputStream * @return */ public static Document readXml(InputStream xmlInputStream){ return readXml(xmlInputStream, false); } public static Document readXml(InputStream xmlInputStream, boolean validate){ // 参考mybatis parsing模块 try { DocumentBuilderFactory factory=DocumentBuilderFactory.newInstance(); factory.setValidating(validate); factory.setNamespaceAware(false); factory.setIgnoringComments(true); factory.setIgnoringElementContentWhitespace(false); factory.setCoalescing(false); factory.setExpandEntityReferences(true); DocumentBuilder builder=factory.newDocumentBuilder(); return builder.parse(xmlInputStream); } catch (ParserConfigurationException e) { throw new RuntimeException(e); } catch (SAXException e) { throw new RuntimeException(e); } catch (IOException e) { throw new RuntimeException(e); } } public static Document readXml(String xmlStr){ return XmlUtil.parseXml(xmlStr); //使用hutool } // -------------------------------------- // 根据路径获取某一节点 public static XPath newXpath(){ return XPathFactory.newInstance().newXPath(); } /** * 根据路径获取某一节点, 语法看 https://www.w3school.com.cn/xpath/xpath_syntax.asp * @param expression * @param root 可以是document, 可以是Node等其他节点 * @param xpath * @return 返回的节点可以修改 */ public static Node evalNode(String expression, Object root, XPath xpath){ return (Node)evaluate(expression, root, XPathConstants.NODE, xpath); } public static NodeList evalNodeList(String expression, Object root, XPath xpath){ return (NodeList)evaluate(expression, root, XPathConstants.NODESET, xpath); } public static Double evalDouble(String expression, Object root, XPath xpath) { return (Double) evaluate(expression, root, XPathConstants.NUMBER, xpath); } public static Boolean evalBoolean(String expression, Object root, XPath xpath) { return (Boolean) evaluate(expression, root, XPathConstants.BOOLEAN, xpath); } public static String evalString(String expression, Object root, XPath xpath) { return (String) evaluate(expression, root, XPathConstants.STRING, xpath); } public static Long evalLong(String expression, Object root, XPath xpath){ return Long.valueOf(evalString(expression, root, xpath)); } public static Integer evalInteger(String expression, Object root, XPath xpath){ return Integer.valueOf(evalString(expression, root, xpath)); } public static Float evalFloat(String expression, Object root, XPath xpath){ return Float.valueOf(evalString(expression, root, xpath)); } public static Short evalShort(String expression, Object root, XPath xpath){ return Short.valueOf(evalString(expression, root, xpath)); } private static Object evaluate(String expression, Object root, QName returnType, XPath xpath) { try { return xpath.evaluate(expression, root, returnType); } catch (Exception e) { throw new RuntimeException("Error evaluating XPath. Cause: " + e, e); } } // -------------------------------------- // 转成string public static String toStr(Node node){ return toStr(node, false); } public static String toStr(Node node, boolean isPretty){ return toStr(node, "utf-8", isPretty); } /** * * @param node * @param charset 编码 * @param isPretty 是否格式化输出 * @return */ public static String toStr(Node node, String charset, boolean isPretty){ final StringWriter writer = StrUtil.getWriter(); final int INDENT_DEFAULT=2; try { XmlUtil.transform(new DOMSource(node), new StreamResult(writer), charset, isPretty ? INDENT_DEFAULT : 0); } catch (Exception e) { throw new UtilException(e, "Trans xml document to string error!"); } return writer.toString(); } //---------------------------------------- // 和java bean转换 public static JSONObject toJSONObject(String xmlStr){ return XML.toJSONObject(xmlStr); } public static JSONObject toJSONObject(Node node){ String xmlStr=toStr(node); return toJSONObject(xmlStr); } public staticT toBean(Node node, Class clazz){ return toJSONObject(node).toBean(clazz); } public static Node toNode(Object obj){ String xml=toXml(obj); Node rootNode=readXml(xml).getFirstChild(); return rootNode; } public static String toXml(Object obj){ return XML.toXml(obj); } }
二丶测试
@Test public void readXmlFromInputStreamTest(){ BufferedInputStream bis=FileUtil.getInputStream("xml/bookstore.xml"); Document document=XmlUtils.readXml(bis); String nodeName=document.getFirstChild().getNodeName(); System.out.println(nodeName); Assert.assertTrue(nodeName.equals("bookstore")); } @Test public void readXmlStringTest() throws IOException { BufferedInputStream bis=FileUtil.getInputStream("xml/bookstore.xml"); String xmlStr=StreamUtils.copyToString(bis, Charset.defaultCharset()); Document document=XmlUtils.readXml(xmlStr); String nodeName=document.getFirstChild().getNodeName(); System.out.println(nodeName); Assert.assertTrue(nodeName.equals("bookstore")); } // -------------------------------------------- xpath /* https://www.w3school.com.cn/xpath/xpath_syntax.asp nodename 选取此节点的所有子节点。 / 从根节点选取。 // 从匹配选择的当前节点选择文档中的节点,而不考虑它们的位置。 . 选取当前节点。 .. 选取当前节点的父节点。 @ 选取属性。 */ @Test public void evalNodeTest(){ BufferedInputStream bis=FileUtil.getInputStream("xml/bookstore.xml"); Document document=XmlUtils.readXml(bis); XPath xpath=XmlUtils.newXpath(); // 1. 使用xpath表达式读取根节点 Node rootNode=XmlUtils.evalNode("/bookstore", document, xpath); Assert.assertEquals("bookstore", rootNode.getNodeName()); // 2. 使用xpath表达式读取nodeList NodeList bookNodeList =XmlUtils.evalNodeList("/bookstore/book", document, xpath); Node bookNode=null; for(int i=0; ibookList=bookstore.getBook(); Book book1=bookList.get(0); Assert.assertTrue(book1.getTitle().getLang().equals("en")); Assert.assertTrue(book1.getTitle().getContent().equals("Harry Potter")); Assert.assertTrue(book1.getAuthor().equals("J K. Rowling")); Book book2=bookList.get(1); Assert.assertTrue(book2.getTitle().getLang().equals("cn")); Assert.assertTrue(book2.getTitle().getContent().equals("where I am from")); Assert.assertTrue(book2.getAuthor().equals("timfruit")); }
1.SpringMVC,Spring Web MVC是一种基于Java的实现了Web MVC设计模式的请求驱动类型的轻量级Web框架。2.Shiro,Apache Shiro是Java的一个安全框架。3.Mybatis,MyBatis 是支持普通 SQL查询,存储过程和高级映射的优秀持久层框架。4.Dubbo,Dubbo是一个分布式服务框架。5.Maven,Maven是个项目管理和构建自动化工具。6.RabbitMQ,RabbitMQ是用Erlang实现的一个高并发高可靠AMQP消息队列服务器。7.Ehcache,EhCache 是一个纯Java的进程内缓存框架。
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