com.geyao.mybatis.mapper BlogMapper类 package com.geyao.mybatis.mapper; import java.util.List; import com.geyao.mybatis.pojo.Blog; public interface BlogMapper { Blog selectBlog(Integer id); Blog selectBlog2(Integer id); List<Blog> selectBlogByTitle(String title); } BlogMapper.xml<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd"> <!-- 为这个mapper指定一个唯一的namespace,namespace的值习惯上设置成包名+sql映射文件名,这样就能够保证namespace的值是唯一的 例如namespace="me.gacl.mapping.userMapper"就是me.gacl.mapping(包名)+userMapper(userMapper.xml文件去除后缀) --> <mapper namespace="com.geyao.mybatis.mapper.BlogMapper"> <!-- 在select标签中编写查询的SQL语句, 设置select标签的id属性为getUser,id属性值必须是唯一的,不能够重复 使用parameterType属性指明查询时使用的参数类型,resultType属性指明查询返回的结果集类型 resultType="me.gacl.domain.User"就表示将查询结果封装成一个User类的对象返回 User类就是users表所对应的实体类 --> <!-- 根据id查询得到一个user对象 --> <resultMap type="Blog" id="blogResultMap"> <id column="id" property="id" jdbcType="INTEGER"></id> <result column="authod_id" property="authodId" jdbcType="INTEGER"/> </resultMap> <select id="selectBlog" parameterType="int" resultType="Blog"> select id, title, authod_id as authodId, state, featured, style from Blog where id=#{id} </select> <select id="selectBlog2" parameterType="int" resultMap="blogResultMap"> select * from Blog where id=#{id} </select> <select id="selectBlogByTitle" parameterType="String" resultMap="blogResultMap"> select * from Blog where title like #{title} </select> </mapper> com.geyao.mybatis.pojoBlog类 package com.geyao.mybatis.pojo; public class Blog { private Integer id; private String title; private int authodId; private String state; private Boolean featured; private String style; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getTitle() { return title; } public void setTitle(String title) { this.title = title; } public int getAuthodId() { return authodId; } public void setAuthodId(int authodId) { this.authodId = authodId; } public String getState() { return state; } public void setState(String state) { this.state = state; } public Boolean getFeatured() { return featured; } public void setFeatured(Boolean featured) { this.featured = featured; } public String getStyle() { return style; } public void setStyle(String style) { this.style = style; } @Override public String toString() { return "Blog [id=" + id + ", title=" + title + ", authodId=" + authodId + ", state=" + state + ", featured=" + featured + ", style=" + style + "]"; } } com.geyao.mybatis.utilMybatisUtil类 package com.geyao.mybatis.util; import java.io.InputStream; import java.io.Reader; import org.apache.ibatis.io.Resources; import org.apache.ibatis.session.SqlSession; import org.apache.ibatis.session.SqlSessionFactory; import org.apache.ibatis.session.SqlSessionFactoryBuilder; public class MyBatisUtil { private static SqlSessionFactory sqlSessionFactory =null; static { try { InputStream in = Resources.getResourceAsStream("mybatis-config.xml"); sqlSessionFactory = new SqlSessionFactoryBuilder().build(in); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } private MyBatisUtil() {} public static SqlSession getSqlSession() { return sqlSessionFactory.openSession(); } } log4j.properties### \u914D\u7F6E\u6839 ### log4j.rootLogger = debug,console ,fileAppender,dailyRollingFile,ROLLING_FILE,MAIL,DATABASE ### \u8BBE\u7F6E\u8F93\u51FAsql\u7684\u7EA7\u522B\uFF0C\u5176\u4E2Dlogger\u540E\u9762\u7684\u5185\u5BB9\u5168\u90E8\u4E3Ajar\u5305\u4E2D\u6240\u5305\u542B\u7684\u5305\u540D ### log4j.logger.org.apache=dubug log4j.logger.java.sql.Connection=dubug log4j.logger.java.sql.Statement=dubug log4j.logger.java.sql.PreparedStatement=dubug log4j.logger.java.sql.ResultSet=dubug ### \u914D\u7F6E\u8F93\u51FA\u5230\u63A7\u5236\u53F0 ### log4j.appender.console = org.apache.log4j.ConsoleAppender log4j.appender.console.Target = System.out log4j.appender.console.layout = org.apache.log4j.PatternLayout log4j.appender.console.layout.ConversionPattern = %d{ABSOLUTE} %5p %c{1}:%L - %m%n mybatis-config.xml<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd"> <configuration> <typeAliases> <typeAlias type="com.geyao.mybatis.pojo.Blog" alias="Blog"/> </typeAliases> <environments default="development"> <environment id="development"> <transactionManager type="JDBC" /> <!-- 配置数据库连接信息 --> <dataSource type="POOLED"> <property name="driver" value="com.mysql.cj.jdbc.Driver" /> <property name="url" value="jdbc:mysql://localhost:3306/mybatis?serverTimezone=GMT%2B8" /> <property name="username" value="root" /> <property name="password" value="123" /> </dataSource> </environment> </environments> <mappers> <!-- 注册userMapper.xml文件, userMapper.xml位于me.gacl.mapping这个包下,所以resource写成me/gacl/mapping/userMapper.xml--> <mapper resource="com/geyao/mybatis/mapper/BlogMapper.xml"/> </mappers> </configuration> 单元测试com.geyao.mybatis.util testSelectBlog类 package com.geyao.mybatis.mapper; import java.util.List; import org.apache.ibatis.session.SqlSession; import org.junit.Test; import com.geyao.mybatis.pojo.Blog; import com.geyao.mybatis.util.MyBatisUtil; public class testSelectBlog { @Test public void testSelectBlogNoInterface() { SqlSession session =MyBatisUtil.getSqlSession(); Blog blog =(Blog)session.selectOne("com.geyao.mybatis.mapper.BlogMapper.selectBlog", 101); session.close(); System.out.println(blog); } @Test public void testSelectBlog() { SqlSession session =MyBatisUtil.getSqlSession(); BlogMapper blogMapper =session.getMapper(BlogMapper.class); Blog blog = blogMapper.selectBlog(1); System.out.println(blog); } @Test public void testSelectBlog2() { SqlSession session =MyBatisUtil.getSqlSession(); BlogMapper blogMapper =session.getMapper(BlogMapper.class); Blog blog = blogMapper.selectBlog2(1); System.out.println(blog); } @Test public void testselectBlogByTitle() { SqlSession session =MyBatisUtil.getSqlSession(); BlogMapper blogMapper =session.getMapper(BlogMapper.class); List<Blog> blogList = blogMapper.selectBlogByTitle("%g%"); System.out.println(blogList); } } jar包