目錄結構

com.geyao.mybatis.mapper

BlogMapper類

package com.geyao.mybatis.mapper;import com.geyao.mybatis.pojo.Blog;public interface BlogMapper {Blog selectBlog(String id); }

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"> <!-- 為這個mapper指定一個唯一的namespace，namespace的值習慣上設置成包名+sql映射文件名，這樣就能夠保證namespace的值是唯一的 例如namespace="me.gacl.mapping.userMapper"就是me.gacl.mapping(包名)+userMapper(userMapper.xml文件去除后綴)--> <mapper namespace="com.geyao.mybatis.mapper.BlogMapper"><!-- 在select標簽中編寫查詢的SQL語句， 設置select標簽的id屬性為getUser，id屬性值必須是唯一的，不能夠重復使用parameterType屬性指明查詢時使用的參數類型，resultType屬性指明查詢返回的結果集類型resultType="me.gacl.domain.User"就表示將查詢結果封裝成一個User類的對象返回User類就是users表所對應的實體類--><!-- 根據id查詢得到一個user對象--><select id="selectBlog" resultType="Blog">select * from Blog where id=#{id}</select> </mapper>

com.geyao.mybatis.pojo

Blog類

package com.geyao.mybatis.pojo;public class Blog {private String id;private String title;private int authod_id;private String state;private Boolean featured;private String style;public String getId() {return id;}public void setId(String id) {this.id = id;}public String getTitle() {return title;}public void setTitle(String title) {this.title = title;}public int getAuthod_id() {return authod_id;}public void setAuthod_id(int authod_id) {this.authod_id = authod_id;}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;}@Overridepublic String toString() {return "Blog [id=" + id + ", title=" + title + ", authod_id=" + authod_id + ", state=" + state + ", featured="+ featured + ", style=" + style + "]";}}

com.geyao.mybatis.util

MybatisUtil類

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 blocke.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" /><!-- 配置數據庫連接信息 --><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><!-- 注冊userMapper.xml文件， userMapper.xml位于me.gacl.mapping這個包下，所以resource寫成me/gacl/mapping/userMapper.xml--><mapper resource="com/geyao/mybatis/mapper/BlogMapper.xml"/></mappers> </configuration>

單元測試

com.geyao.mybatis.util

testSelectBlog類

package com.geyao.mybatis.mapper;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 testSelectBlog() {SqlSession session =MyBatisUtil.getSqlSession();BlogMapper blogMapper =session.getMapper(BlogMapper.class);Blog blog = blogMapper.selectBlog("1");System.out.println(blog); } }

jar包

鏈接：https://pan.baidu.com/s/1g6NgzfLc5uK9S4VL-03lHg
提取碼：4r2m

運行結果

總結

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