Mybatis手写Mybatis框架之XML文件解析-----Mybatis框架

秒速五厘米 2024-03-24 21:32 76阅读 0赞

>     package com.powernode.xml.test;
>     
>     import org.dom4j.Document;
>     import org.dom4j.DocumentException;
>     import org.dom4j.Element;
>     import org.dom4j.Node;
>     import org.dom4j.io.SAXReader;
>     import org.junit.Test;
>     
>     import java.io.InputStream;
>     import java.lang.invoke.VarHandle;
>     import java.util.List;
>     
>     public class ParseXMLByDom4jTest
>     {
>         @Test
>         public void TestParseSqlMapperXML() throws DocumentException
>         {
>             SAXReader saxReader = new SAXReader();
>             //把我们解析到的xml文件名字传过来给它创建流
>             InputStream stream = ClassLoader.getSystemClassLoader().getResourceAsStream("CarMapper.xml");
>             //创建一个XML的Document对象
>             Document document = saxReader.read(stream);
>             //获取根节点的相关信息
>             Element rootElement = document.getRootElement();
>     //        String xpath = "mapper";
>     //        Element e = (Element) document.selectSingleNode(xpath);
>     //        System.out.println(e.attributeValue("namespace"));
>     //        System.out.println(e.getName());
>             //拿到命名空间
>             String namespace = rootElement.attributeValue("namespace");
>             System.out.println(namespace);
>             List<Element> elements = rootElement.elements();
>             //把子节点都遍历一下,获取SQL语句的mapper信息
>             elements.forEach(ele ->
>             {
>                 Element element = (Element) ele;
>                 //获取SQL的ID
>                 String id = element.attributeValue("id");
>                 System.out.println(id);
>                 //没有这个属性会返回一个null字符串
>                 //获取SQL对应的POJO类
>                 String resultType = element.attributeValue("resultType");
>                 System.out.println(resultType);
>                 //获取标签中的SQL语句
>                 //获取标签中的文本内容,同时去除前后空白
>                 String sql = element.getTextTrim();
>                 System.out.println(sql);
>                 //解析完成
>                 //mybatis封装了JDBC,要执行带有?的SQL语句
>                 sql = sql.replaceAll("#\\{[0-9A-Za-z_$]*}","?");
>                 System.out.println(sql);
>             });
>         }
>         @Test
>         public void TestParseMybatisConfigXML() throws DocumentException
>         {
>             //创建SAXReader对象
>             SAXReader reader = new SAXReader();
>             //读XML文件,我们传给它一个文件流,他会给我们创建一个文档对象Document
>             InputStream resourceAsStream = ClassLoader.getSystemClassLoader().getResourceAsStream("mybatis-config.xml");
>             Document mybatisXML = reader.read(resourceAsStream);
>     //                System.out.println(mybatisXML.toString());
>             //获取文档中的根标签,
>             Element rootElement = mybatisXML.getRootElement();
>             String rootEleName = rootElement.getName();
>             System.out.println("根标签名字:" + rootElement.getName());
>             //获取default默认的环境ID
>             //里面/代表根,这个写法代表从跟下开始找configuration标签
>             //然后找configuration下的environments子标签
>             String xpath = "/configuration/environments";//Xpath是做标签的路径匹配的,能够让我们快速定位XML文件中的元素
>             Element environments = (Element)mybatisXML.selectSingleNode(xpath);
>             //因为Element是Node的子类,方法更多,使用更便捷,所以我们在这里强转成子类对象
>     //        System.out.println(environments);
>             String defaultName = environments.attributeValue("default");
>             System.out.println("默认环境的ID" + defaultName);
>             //我们要获取具体的环境environment
>             xpath = "/configuration/environments/environment[@id='"+ defaultName +"']";
>             Element environment = (Element)mybatisXML.selectSingleNode(xpath);
>             //获取environment下的transactionManager节点
>             Element transactionManager = environment.element("transactionManager");
>     //        获取事务管理器的类型
>             String transactionType = transactionManager.attributeValue("type");
>             System.out.println("事务管理器类型" + transactionType);
>     //        获取数据源的类型
>             Element dataSource = environment.element("dataSource");
>             String dataSourceType = dataSource.attributeValue("type");
>     //        System.out.println(dataSourceType);
>             //获取dataSource节点下的所有子节点
>             List<Element> propertyElts = dataSource.elements();
>             propertyElts.forEach(property ->
>             {
>                 String name = property.attributeValue("name");
>                 String value = property.attributeValue("value");
>                 System.out.println("类型名" + name);
>                 System.out.println("值" + value);
>             });
>             //获取所有的Mapper标签
>             xpath = "//mapper";
>             //当不想从根开始获取,想从任意位置获取某个标签就需要Xpath
>             //使用两个斜杠就表示不是从根开始
>             List<Node> mappers = mybatisXML.selectNodes(xpath);
>             //遍历所有的Mapper
>             mappers.forEach(mapper ->
>             {
>                 Element mapperEle = (Element) mapper;
>                 String resource = mapperEle.attributeValue("resource");
>                 System.out.println("源文件" + resource);
>             });
>         }
>     }
> 
>     package com.powernode.xml.test;
>     
>     import org.dom4j.Document;
>     import org.dom4j.DocumentException;
>     import org.dom4j.Element;
>     import org.dom4j.Node;
>     import org.dom4j.io.SAXReader;
>     import org.junit.Test;
>     
>     import java.io.InputStream;
>     import java.lang.invoke.VarHandle;
>     import java.util.List;
>     
>     public class ParseXMLByDom4jTest
>     {
>         @Test
>         public void TestParseSqlMapperXML() throws DocumentException
>         {
>             SAXReader saxReader = new SAXReader();
>             //把我们解析到的xml文件名字传过来给它创建流
>             InputStream stream = ClassLoader.getSystemClassLoader().getResourceAsStream("CarMapper.xml");
>             //创建一个XML的Document对象
>             Document document = saxReader.read(stream);
>             //获取根节点的相关信息
>             Element rootElement = document.getRootElement();
>     //        String xpath = "mapper";
>     //        Element e = (Element) document.selectSingleNode(xpath);
>     //        System.out.println(e.attributeValue("namespace"));
>     //        System.out.println(e.getName());
>             //拿到命名空间
>             String namespace = rootElement.attributeValue("namespace");
>             System.out.println(namespace);
>             List<Element> elements = rootElement.elements();
>             //把子节点都遍历一下,获取SQL语句的mapper信息
>             elements.forEach(ele ->
>             {
>                 Element element = (Element) ele;
>                 //获取SQL的ID
>                 String id = element.attributeValue("id");
>                 System.out.println(id);
>                 //没有这个属性会返回一个null字符串
>                 //获取SQL对应的POJO类
>                 String resultType = element.attributeValue("resultType");
>                 System.out.println(resultType);
>                 //获取标签中的SQL语句
>                 //获取标签中的文本内容,同时去除前后空白
>                 String sql = element.getTextTrim();
>                 System.out.println(sql);
>                 //解析完成
>                 //mybatis封装了JDBC,要执行带有?的SQL语句
>                 sql = sql.replaceAll("#\\{[0-9A-Za-z_$]*}","?");
>                 System.out.println(sql);
>             });
>         }
>         @Test
>         public void TestParseMybatisConfigXML() throws DocumentException
>         {
>             //创建SAXReader对象
>             SAXReader reader = new SAXReader();
>             //读XML文件,我们传给它一个文件流,他会给我们创建一个文档对象Document
>             InputStream resourceAsStream = ClassLoader.getSystemClassLoader().getResourceAsStream("mybatis-config.xml");
>             Document mybatisXML = reader.read(resourceAsStream);
>     //                System.out.println(mybatisXML.toString());
>             //获取文档中的根标签,
>             Element rootElement = mybatisXML.getRootElement();
>             String rootEleName = rootElement.getName();
>             System.out.println("根标签名字:" + rootElement.getName());
>             //获取default默认的环境ID
>             //里面/代表根,这个写法代表从跟下开始找configuration标签
>             //然后找configuration下的environments子标签
>             String xpath = "/configuration/environments";//Xpath是做标签的路径匹配的,能够让我们快速定位XML文件中的元素
>             Element environments = (Element)mybatisXML.selectSingleNode(xpath);
>             //因为Element是Node的子类,方法更多,使用更便捷,所以我们在这里强转成子类对象
>     //        System.out.println(environments);
>             String defaultName = environments.attributeValue("default");
>             System.out.println("默认环境的ID" + defaultName);
>             //我们要获取具体的环境environment
>             xpath = "/configuration/environments/environment[@id='"+ defaultName +"']";
>             Element environment = (Element)mybatisXML.selectSingleNode(xpath);
>             //获取environment下的transactionManager节点
>             Element transactionManager = environment.element("transactionManager");
>     //        获取事务管理器的类型
>             String transactionType = transactionManager.attributeValue("type");
>             System.out.println("事务管理器类型" + transactionType);
>     //        获取数据源的类型
>             Element dataSource = environment.element("dataSource");
>             String dataSourceType = dataSource.attributeValue("type");
>     //        System.out.println(dataSourceType);
>             //获取dataSource节点下的所有子节点
>             List<Element> propertyElts = dataSource.elements();
>             propertyElts.forEach(property ->
>             {
>                 String name = property.attributeValue("name");
>                 String value = property.attributeValue("value");
>                 System.out.println("类型名" + name);
>                 System.out.println("值" + value);
>             });
>             //获取所有的Mapper标签
>             xpath = "//mapper";
>             //当不想从根开始获取,想从任意位置获取某个标签就需要Xpath
>             //使用两个斜杠就表示不是从根开始
>             List<Node> mappers = mybatisXML.selectNodes(xpath);
>             //遍历所有的Mapper
>             mappers.forEach(mapper ->
>             {
>                 Element mapperEle = (Element) mapper;
>                 String resource = mapperEle.attributeValue("resource");
>                 System.out.println("源文件" + resource);
>             });
>         }
>     }

>     <?xml version="1.0" encoding="UTF-8"?>
>     <project xmlns="http://maven.apache.org/POM/4.0.0"
>              xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
>              xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
>         <modelVersion>4.0.0</modelVersion>
>     
>         <groupId>com.powernode</groupId>
>         <artifactId>parse-xml-by-Dom4J</artifactId>
>         <version>1.0-SNAPSHOT</version>
>         <packaging>jar</packaging>
>         <dependencies>
>     
>             <dependency>
>                 <groupId>org.dom4j</groupId>
>                 <artifactId>dom4j</artifactId>
>                 <version>2.1.3</version>
>             </dependency>
>     
>             <dependency>
>                 <groupId>jaxen</groupId>
>                 <artifactId>jaxen</artifactId>
>                 <version>1.2.0</version>
>             </dependency>
>             <dependency>
>                 <groupId>junit</groupId>
>                 <artifactId>junit</artifactId>
>                 <version>4.13.2</version>
>                 <scope>test</scope>
>             </dependency>
>         </dependencies>
>         <properties>
>             <maven.compiler.source>17</maven.compiler.source>
>             <maven.compiler.target>17</maven.compiler.target>
>             <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
>         </properties>
>     
>     </project>
> 
>     <?xml version="1.0" encoding="UTF-8"?>
>     <project xmlns="http://maven.apache.org/POM/4.0.0"
>              xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
>              xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
>         <modelVersion>4.0.0</modelVersion>
>     
>         <groupId>com.powernode</groupId>
>         <artifactId>parse-xml-by-Dom4J</artifactId>
>         <version>1.0-SNAPSHOT</version>
>         <packaging>jar</packaging>
>         <dependencies>
>     
>             <dependency>
>                 <groupId>org.dom4j</groupId>
>                 <artifactId>dom4j</artifactId>
>                 <version>2.1.3</version>
>             </dependency>
>     
>             <dependency>
>                 <groupId>jaxen</groupId>
>                 <artifactId>jaxen</artifactId>
>                 <version>1.2.0</version>
>             </dependency>
>             <dependency>
>                 <groupId>junit</groupId>
>                 <artifactId>junit</artifactId>
>                 <version>4.13.2</version>
>                 <scope>test</scope>
>             </dependency>
>         </dependencies>
>         <properties>
>             <maven.compiler.source>17</maven.compiler.source>
>             <maven.compiler.target>17</maven.compiler.target>
>             <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
>         </properties>
>     
>     </project>