Java之XML操作：从XML中直接获取数据

　　本文介绍如何将数据记录在XML文件中，然后通过DOM4J直接从XML中读取到数据。

依赖包：

<dependency>
    <groupId>dom4j</groupId>
    <artifactId>dom4j</artifactId>
    <version>1.6.1</version>
</dependency>

工具类代码：

 package testTraffic.utils;

 import org.dom4j.Document;
 import org.dom4j.DocumentException;
 import org.dom4j.Element;
 import org.dom4j.io.SAXReader;
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.URISyntaxException;
 import java.util.ArrayList;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;

 /**
  * XmlUtils class
  *
  * @author gongxingrui
  * @date 2018-12-07
  **/
 public class XmlUtils {

     public static Document readXml(String filePath) throws DocumentException {
         return readXml(new File(filePath));
     }

     public static Document readXml(File file) throws DocumentException {
         SAXReader reader = new SAXReader();
         return reader.read(file);
     }

     public static Document readXml(InputStream inputStream) throws DocumentException {
         SAXReader reader = new SAXReader();
         return reader.read(inputStream);
     }

     public static Document readXmlFromResources(String resource) throws DocumentException, IOException, URISyntaxException {
         SAXReader reader = new SAXReader();
         return reader.read(ResourcesUtils.getResourceAsFile(resource));
     }

     public static String getAttribute(Element element, String attrName) {
         return element.attributeValue(attrName);
     }

     public static String getText(Element element) {
         return element.getText();
     }

     public static List<Element> getElements(Element element, String tagName) {
         return element.elements(tagName);
     }

     /**
      * 根据节点名称获取子节点数据
      */
     public static String getElementText(String resource, String qName) throws Exception {
         Element root = readXmlFromResources(resource).getRootElement();
         String text = root.elementText(qName);
         return text.trim();
     }

     /**
      * 根据节点名称获取子节点的子节点数据
      */
     public static String getElementText(String resource, String qName, String SubQName) throws Exception {
         Element root = readXmlFromResources(resource).getRootElement();
         String text = root.element(qName).elementText(SubQName);
         return text.trim();
     }

     /**
      * 根据节点名称获取子节点的子节点的数据列表
      */
     public static List<String> getElementTextList(String resource, String qName) throws Exception {
         List<Element> elementList = readXmlFromResources(resource).getRootElement().element(qName).elements();
         List<String> list = new ArrayList<>();
         for (Element e : elementList) {
             list.add(e.getTextTrim());
         }
         return list;
     }

 }

测试代码：

    @Test
    public void testXML6() throws Exception {
        String path2 = "shelby/data/sql/demo/sql2.xml";
        String s = XmlUtils.getElementText(path2, "insert_1");
        logger.info(s);

        List<String> list = XmlUtils.getElementTextList(path2, "del_group");
        logger.info(list);

        String s2 = XmlUtils.getElementText(path2, "del_group_2", "del_2");
        logger.info(s2);
    }   

测试结果：

-- ::14.746 INFO  testTraffic.testDemo.testXmlDemo testXML6 : insert into `t_admin_user` (`id`, `user_name`, `user_password`, `del_flag`, `create_time`, `update_time`)
        VALUES( null,'testuser','testuser123','','2019-01-21 19:43:58','2019-01-22 19:44:03');
-- ::14.763 INFO  testTraffic.testDemo.testXmlDemo testXML6 : [delete from t_admin_user WHERE user_name = 'testuser';, delete from t_admin_user WHERE user_name = 'testuser2';]
-- ::14.768 INFO  testTraffic.testDemo.testXmlDemo testXML6 : delete from t_admin_user WHERE user_name = 'testuser2';

Process finished with exit code 

XML文档：

 <?xml version="1.0" encoding="UTF-8"?>
 <mybatisGroup id="预置数据语句">
     <del_1 id="del_1" type="delete">
         delete from t_admin_user WHERE user_name = 'testuser';
     </del_1>
     <del_2 id="del_2" type="delete">
         delete from t_admin_user WHERE user_name = 'testuser2';
     </del_2>
     <insert_1 id="insert_1" type="insert">
         insert into `t_admin_user` (`id`, `user_name`, `user_password`, `del_flag`, `create_time`, `update_time`)
         VALUES( null,'testuser','testuser123','0','2019-01-21 19:43:58','2019-01-22 19:44:03');
     </insert_1>

     <del_group>
         <statement>
             delete from t_admin_user WHERE user_name = 'testuser';
         </statement>
         <statement>
             delete from t_admin_user WHERE user_name = 'testuser2';
         </statement>
     </del_group>

     <del_group_2>
         <del_1>
             delete from t_admin_user WHERE user_name = 'testuser';
         </del_1>
         <del_2>
             delete from t_admin_user WHERE user_name = 'testuser2';
         </del_2>
         <del_3>
             delete from t_admin_user WHERE user_name = 'testuser3';
         </del_3>
     </del_group_2>

 </mybatisGroup>