XML解析之二—— Dom4j、JAXP、JDom(含XPath)
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XML解析开发包 Dom4J使用dom4j解析xml前，先要导入jar包dom4j.jar包和jaxen.jar包dom4j官网： 点击打开链接 DOM4j中，获得Document对象的方式有三种： 1.读取XML文件,获得document对象 SAXReader reader = new SAXReader(); Document document = reader.read(new File("input.xml")); 2.解析XML形式的文本,得到document对象. String text = "<members></members>"; Document document = DocumentHelper.parseText(text); 3.主动创建document对象. Document document = DocumentHelper.createDocument(); //创建根节点 Element root = document.addElement("members"); 节点对象 1.获取文档的根节点. Element root = document.getRootElement(); 2.取得某个节点的子节点. Element element=node.element(“书名"); 3.取得节点的文字 String text=node.getText(); 4.取得某节点下所有名为“member”的子节点，并进行遍历. List nodes = rootElm.elements("member"); } <?xml version="1.0" encoding="UTF-8"?>
<books>
<book 出版日期="2013-08-27" 出版社="人民出版社" 编号="b1" 页数="120" >
<name>葵花宝典</name>
<author>东方不败</author>
<author>春哥</author>
<price>18元</price>
<author>林平之</author>
<desc>欲练此功，必先自宫222221!!</desc>
<author>曾哥</author>
</book>
<book 出版社="邮电出版社" 类别="武侠" 编号="b2">
<name>辟邪剑谱</name>
<author>岳不群</author>
<price>20元</price>
<desc>欲练此功，必先自宫2222222!!</desc>
</book>
</books>
解析以上xml文件的代码 public class DOM4J {
public static void main(String[] args) throws Exception {
test7();
}
/**
* XPATH的写法
* @throws Exception
*/
private static void test7() throws Exception {
SAXReader reader = new SAXReader();
Document document = reader.read("src/persons.xml");
/*List<Node> list = document.selectNodes("/books/book");
Node node = document.selectSingleNode("//book[2]");*/
Node node = document.selectSingleNode("//person[@username='aa' and @password='aa']");
Element e = (Element) node;
System.out.println(e.element("name").getText());
}
/**
* 遍历所有的节点
* @throws Exception
*/
private static void test6() throws Exception {
SAXReader reader = new SAXReader();
Document document = reader.read("src/book.xml");
Element root = document.getRootElement();
list(root);
}
private static void list(Element root) {
System.out.println(root.getName());
List<Element> list = root.elements();
for(int i=0;i<list.size();i++){
Element e = list.get(i);
list(e);
}
}
/**
* 在指定的位置添加
* @throws Exception
*/
private static void test5() throws Exception {
SAXReader reader = new SAXReader();
Document document = reader.read("src/book.xml");
Element root = document.getRootElement();
//创建一个元素
Element author = DocumentHelper.createElement("author");
author.setText("春哥");
//在第一本书的第一个作者之前 添加一个作者 春哥
List<Element> list = root.element("book").elements();
list.add(2,author);
//回写XML
OutputFormat format = OutputFormat.createPrettyPrint();
format.setEncoding("UTF-8");
XMLWriter writer = new XMLWriter(new FileWriter("src/book.xml"),format);
writer.write(document);
writer.close();
}
/**
* 删除某个节点:删除第一本书的第四个作者
* @throws Exception
*/
public static void test4() throws Exception{
SAXReader reader = new SAXReader();
Document document = reader.read("src/book.xml");
Element root = document.getRootElement();
Element author = (Element) root.element("book").elements("author").get(3);
//删除的话
author.getParent().remove(author);
//回写XML
OutputFormat format = OutputFormat.createPrettyPrint();
format.setEncoding("UTF-8");
XMLWriter writer = new XMLWriter(new FileWriter("src/book.xml"),format);
writer.write(document);
writer.close();
}
/**
* 修改某个节点：修改第一本书中的售价 18元
* @throws Exception
*/
private static void test3() throws Exception {
SAXReader reader = new SAXReader();
Document document = reader.read("src/book.xml");
Element root = document.getRootElement();
root.element("book").element("price").setText("18元");
//回写XML
OutputFormat format = OutputFormat.createPrettyPrint();
format.setEncoding("UTF-8");
XMLWriter writer = new XMLWriter(new FileWriter("src/book.xml"),format);
writer.write(document);
writer.close();
}
/**
* 使用dom4j添加一个节点：在第一本书上添加一个作者
* @throws Exception
*/
private static void test2() throws Exception {
SAXReader reader = new SAXReader();
Document document = reader.read("src/book.xml");
Element root = document.getRootElement();
//找到第一本书
root.element("book").addElement("author").setText("春哥");
//回写XML
OutputFormat format = OutputFormat.createPrettyPrint();
format.setEncoding("UTF-8");
XMLWriter writer = new XMLWriter(new FileWriter("src/book.xml"),format);
writer.write(document);
writer.close();
}
/**
* 使用dom4j查找某个节点
* @throws Exception
*/
private static void test1() throws Exception {
//创建一个解析器
SAXReader reader = new SAXReader();
//解析XML文档
Document document = reader.read("src/book.xml");
//获得跟节点
Element root = document.getRootElement();
/* //获得所有的书节点
List<Element> list = root.elements("book");
Element book1 = list.get(0);//获得第一本书
*/
//获得第一本书
Element book = root.element("book");
List<Element> list = book.elements("author");
Element author = list.get(0);
String value = author.getText();//获得作者中的内容
System.out.println(value);
Element author1 = (Element) root.element("book").elements("author").get(0);
System.out.println(author1.getText());
}
}说明：test7使用的XPath方式 （编辑：李大同） 【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容! |