dom4j解析简单的xml文件 解析元素并封装到对象

Posted 2022-02-03 mozq

 

 1 package cn.itcast.xml;
 2 
 3 import cn.itcast.domain.Book;
 4 import org.dom4j.Document;
 5 import org.dom4j.DocumentException;
 6 import org.dom4j.Element;
 7 import org.dom4j.Node;
 8 import org.dom4j.io.SAXReader;
 9 import org.junit.Before;
10 import org.junit.Test;
11 
12 import java.io.FileNotFoundException;
13 import java.io.InputStream;
14 import java.util.ArrayList;
15 import java.util.List;
16 
17 public class Dom4jDemo 
18 
19     private Document document;
20 
21     @Before
22     public void init() throws DocumentException 
23         SAXReader reader = new SAXReader();
24         InputStream is = Dom4jDemo.class.getClassLoader().getResourceAsStream("book.xml");
25 
26         document = reader.read(is);
27     
28 
29     @Test
30     public void parseMethod2() throws DocumentException 
31         //获取文档根元素，books
32         Element root = document.getRootElement();
33 
34         //获取所有book元素
35         List<Element> bookElements = root.elements();
36 
37         //解析所有book元素，并添加到books集合中
38         List<Book> books = new ArrayList<>();
39 
40         for (Element bookElement : bookElements) 
41             //获取author属性值
42             String author = bookElement.attributeValue("author");
43             //获取子元素name的文本
44             String name = bookElement.element("name").getText();
45             //获取子元素price的文本
46             String priceStr = bookElement.element("price").getText();
47             double price = Double.parseDouble(priceStr);
48             //创建对应的book对象，并添加到books集合中
49             books.add(new Book(author, name, price));
50         
51 
52         //打印
53         books.forEach(System.out::println);
54 
55     
56 
57     @Test
58     public void parseMethod1() throws FileNotFoundException, DocumentException 
59         //获取根元素
60         Element root = document.getRootElement();
61         System.out.println(root.getName());
62 
63         List<Book> books = new ArrayList<>();
64 
65         //获取所有book元素，解析并保存到books集合中。
66         List<Node> bookNodes = document.selectNodes("/books/book");
67         for (Node bookNode : bookNodes) 
68             //获取作者
69             String author = bookNode.valueOf("@author");
70 //            System.out.println(author);
71 
72             /*
73                 斜杠开头表示文档，中间的斜杠则表示直接子节点
74                 错误代码：
75                     String name = bookNode.valueOf("/name");
76                     表示选区文档下的name元素，而文档下只有books元素。
77              */
78             //获取书名
79             List<Node> nameNodes = bookNode.selectNodes("name");
80             String bookName = nameNodes.get(0).getText();
81 //            System.out.println(bookName);
82 
83             //获取价格
84             List<Node> priceNodes = bookNode.selectNodes("price");
85             double price = (double) Double.parseDouble(priceNodes.get(0).getText());
86 
87             books.add(new Book(author, bookName, price));
88         
89 
90         //打印结果
91         books.forEach(System.out::println);
92     
93 

Dom4jDemo.java

 1 package cn.itcast.domain;
 2 
 3 public class Book 
 4     private String author;
 5     private String name;
 6     private Double price;
 7 
 8     public Book()
 9 
10     public Book(String author, String name, Double price) 
11         this.author = author;
12         this.name = name;
13         this.price = price;
14     
15 
16     public String getAuthor() 
17         return author;
18     
19 
20     public void setAuthor(String author) 
21         this.author = author;
22     
23 
24     public String getName() 
25         return name;
26     
27 
28     public void setName(String name) 
29         this.name = name;
30     
31 
32     public Double getPrice() 
33         return price;
34     
35 
36     public void setPrice(Double price) 
37         this.price = price;
38     
39 
40     @Override
41     public String toString() 
42         return "Book" +
43                 "author=‘" + author + ‘\‘‘ +
44                 ", name=‘" + name + ‘\‘‘ +
45                 ", price=" + price +
46                 ‘‘;
47     
48 

Book.java

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <books>
 3     <book author="天蚕土豆">
 4         <name>斗破苍穹</name>
 5         <price>86</price>
 6     </book>
 7     <book author="萧潜">
 8         <name>缥缈之旅</name>
 9         <price>92</price>
10     </book>
11     <book author="萧鼎">
12         <name>诛仙</name>
13         <price>98</price>
14     </book>
15     <book author="天下霸唱">
16         <name>鬼吹灯</name>
17         <price>124</price>
18     </book>
19     <book author="辰东">
20         <name>神墓</name>
21         <price>128</price>
22     </book>
23 </books>

book.xml

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <project xmlns="http://maven.apache.org/POM/4.0.0"
 3          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 4          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 5     <modelVersion>4.0.0</modelVersion>
 6 
 7     <groupId>cn.itcast.xml-parser</groupId>
 8     <artifactId>xml-parser-demo1</artifactId>
 9     <version>1.0-SNAPSHOT</version>
10 
11     <dependencies>
12         <!-- https://mvnrepository.com/artifact/org.dom4j/dom4j -->
13         <dependency>
14             <groupId>org.dom4j</groupId>
15             <artifactId>dom4j</artifactId>
16             <version>2.1.1</version>
17         </dependency>
18 
19         <!-- https://mvnrepository.com/artifact/jaxen/jaxen -->
20         <dependency>
21             <groupId>jaxen</groupId>
22             <artifactId>jaxen</artifactId>
23             <version>1.1.6</version>
24         </dependency>
25 
26 
27         <dependency>
28             <groupId>junit</groupId>
29             <artifactId>junit</artifactId>
30             <version>4.12</version>
31         </dependency>
32     </dependencies>
33 
34 </project>

pom.xml

 1 package cn.itcast.xml;
 2 
 3 import org.dom4j.Document;
 4 import org.dom4j.Element;
 5 import org.dom4j.io.SAXReader;
 6 import org.junit.Test;
 7 
 8 import java.util.List;
 9 /*
10 作者：北冥有鱼_很好吃
11 链接：https://www.jianshu.com/p/806bb1bdc06f
12  */
13 public class Dom4j_02
14 
15     @Test
16     public void parse() throws Exception 
17         // 1. 创建一个 saxReader 对象
18         SAXReader saxReader = new SAXReader();
19         // 2. 将数据读取到 document 对象中
20         Document document = saxReader.read(Dom4j_02.class.getClassLoader().getResourceAsStream("servlet.xml"));
21         // 3. 使用 document 对象调用 getRootElement 方法获取根标签, 返回 Element 接口实现类对象
22         Element rootElement = document.getRootElement();
23         // 4. 使用 rootElement 根标签对象调用 elements 方法, 传入 servlet, 获取servlet标签对象
24         List<Element> servletElements = rootElement.elements("servlet");
25         // 5. 遍历, 并获取该标签下的子标签数据内容, 使用父标签对象调用elementText方法, 传入子标签名称获取数据
26         for (Element servlet : servletElements) 
27             String name = servlet.elementText("servlet-name");
28             String cls = servlet.elementText("servlet-class");
29             System.out.println(name + " : " + cls);
30         
31         // 使用 rootElement 根标签对象调用 elements 方法, 传入 servlet-mapping, 获取servlet-mapping标签对象
32         List<Element> mappingElements = rootElement.elements("servlet-mapping");
33         for (Element mapping : mappingElements) 
34             String name = mapping.elementText("servlet-name");
35             String url = mapping.elementText("url-pattern");
36             System.out.println(name + " = " + url);
37         
38     
39 

Dom4j_02.java 解析servlet.xml

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <!--
 3 作者：北冥有鱼_很好吃
 4 链接：https://www.jianshu.com/p/806bb1bdc06f
 5 -->
 6 <servlets>
 7     <servlet>
 8         <servlet-name>servlet1</servlet-name>
 9         <servlet-class>MyServlet1</servlet-class>
10     </servlet>
11     <servlet>
12         <servlet-name>servlet2</servlet-name>
13         <servlet-class>MyServlet2</servlet-class>
14     </servlet>
15     <servlet-mapping>
16         <servlet-name>servlet1</servlet-name>
17         <url-pattern>/s1</url-pattern>
18     </servlet-mapping>
19     <servlet-mapping>
20         <servlet-name>servlet2</servlet-name>
21         <url-pattern>/s2</url-pattern>
22     </servlet-mapping>
23 </servlets>

servlet.xml