这篇文章主要介绍了java操作xml的方法汇总及解析,文中通过示例代码介绍的非常详细，对大家的学习或者工作具有一定的参考学习价值,需要的朋友可以参考下
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();
}
// --------------------------------------
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();
}
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);
}
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 static T 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
@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; i bookList=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"));
}
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持考高分网。
