seo优化网站模板,北京小程序外包,自建网站平台,新乡百度关键词优化外包#xff08;一#xff09;MyBatis快速入门 通过一个案例快速入门Mybatis框架案例#xff1a;查询user表中所有数据1) 创建user表#xff0c;添加数据2) 创建模块#xff0c;导入坐标3) 编写MyBatis核心配置文件--替换连接信息#xff0c;解决硬编码问题4) 编写SQL映…一MyBatis快速入门 通过一个案例快速入门Mybatis框架案例查询user表中所有数据1) 创建user表添加数据2) 创建模块导入坐标3) 编写MyBatis核心配置文件--替换连接信息解决硬编码问题4) 编写SQL映射文件--统一管理sql语句解决硬编码问题5) 编码i. 定义POJO类ii. 加载核心配置文件获取SqlSessionFactory对象iii. 获取SqlSession对象执行SQL语句iv. 释放资源– 1、创建user表添加数据 DROP table IF exists tb_user;CREATE TABLE tb_user(id int primary key auto_increment,username varchar(20),password varchar(30),gender char(1),addr varchar(20) );insert into tb_user(id, username, password, gender, addr) values (1, zhangsan, 123, 男, 广州), (2, 李四, 234, 女, 天津), (3, 王五, 11, 男, 北京);sql语句执行结果2.创建模块导入坐标 pom.xml文件的配置如下?xml version1.0 encodingUTF-8? project xmlnshttp://maven.apache.org/POM/4.0.0xmlns:xsihttp://www.w3.org/2001/XMLSchema-instancexsi:schemaLocationhttp://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsdmodelVersion4.0.0/modelVersiongroupIdcom.itheima/groupIdartifactIdmybatis-demo/artifactIdversion1.0-SNAPSHOT/versionrepositoriesrepositoryidJBoss repository/idurlhttps://repository.jboss.org/nexus/content/repositories/releases//url/repository/repositoriesdependencies!--mybatis依赖--dependencygroupIdorg.mybatis/groupIdartifactIdmybatis/artifactIdversion3.4.5/version/dependency!--mysql驱动--dependencygroupIdmysql/groupIdartifactIdmysql-connector-java/artifactIdversion5.1.46/version/dependency!--单元测试--dependencygroupIdjunit/groupIdartifactIdjunit/artifactIdversion4.13/versionscopetest/scope/dependency!--添加slf4j日志API--dependencygroupIdorg.slf4j/groupIdartifactIdslf4j-api/artifactIdversion1.7.20/version/dependency!--添加logback-classic依赖--dependencygroupIdch.qos.logback/groupIdartifactIdlogback-classic/artifactIdversion1.2.3/version/dependency!--添加logback-core依赖--dependencygroupIdch.qos.logback/groupIdartifactIdlogback-core/artifactIdversion1.2.3/version/dependency/dependencies/projectlogback文件的配置如下?xml version1.0 encodingUTF-8? configuration debugfalse!--定义日志文件的存储地址--property nameLOG_HOME value/home /!--控制台日志 控制台输出 --appender nameSTDOUT classch.qos.logback.core.ConsoleAppenderencoder classch.qos.logback.classic.encoder.PatternLayoutEncoder!--格式化输出%d表示日期%thread表示线程名%-5level级别从左显示5个字符宽度,%msg日志消息%n是换行符--pattern%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{50} - %msg%n/pattern/encoder/appender!--文件日志 --appender nameFILE classch.qos.logback.core.rolling.RollingFileAppenderrollingPolicy classch.qos.logback.core.rolling.TimeBasedRollingPolicy!--日志文件输出的文件名--FileNamePattern${LOG_HOME}/TestWeb.log.%d{yyyy-MM-dd}.log/FileNamePattern!--日志文件保留天数--MaxHistory30/MaxHistory/rollingPolicyencoder classch.qos.logback.classic.encoder.PatternLayoutEncoder!--格式化输出%d表示日期%thread表示线程名%-5level级别从左显示5个字符宽度--pattern%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{50} - %msg%n/pattern/encodertriggeringPolicy classch.qos.logback.core.rolling.SizeBasedTriggeringPolicyMaxFileSize10MB/MaxFileSize/triggeringPolicy/appenderlogger nameorg.hibernate.type.descriptor.sql.BasicBinder levelTRACE /logger nameorg.hibernate.type.descriptor.sql.BasicExtractor levelDEBUG /logger nameorg.hibernate.SQL levelDEBUG /logger nameorg.hibernate.engine.QueryParameters levelDEBUG /logger nameorg.hibernate.engine.query.HQLQueryPlan levelDEBUG /logger namecom.apache.ibatis levelTRACE/logger namejava.sql.Connection levelDEBUG/logger namejava.sql.Statement levelDEBUG/logger namejava.sql.PreparedStatement levelDEBUG/root levelDEBUGappender-ref refSTDOUT /appender-ref refFILE//root /configuration3.编写MyBatis核心配置文件–替换连接信息解决硬编码问题 mybatis核心配置文件参考官网给出的示例 官网https://mybatis.org/mybatis-3/zh/getting-started.html红色框框中的内容是需要根据自己的设置更改的我自己的配置如下?xml version1.0 encodingUTF-8 ? !DOCTYPE configurationPUBLIC -//mybatis.org//DTD Config 3.0//ENhttp://mybatis.org/dtd/mybatis-3-config.dtd configurationenvironments defaultdevelopmentenvironment iddevelopmenttransactionManager typeJDBC/dataSource typePOOLED!-- 数据库链接信息 --property namedriver valuecom.mysql.jdbc.Driver/property nameurl valuejdbc:mysql://127.0.0.1:3306/mybatis?useSSLfalse/property nameusername valueroot/property namepassword value111111//dataSource/environment/environmentsmappersmapper resourceUserMapper.xml//mappers /configuration4.编写SQL映射文件–统一管理sql语句解决硬编码问题 sql映射配置文件参考官网给出的示例 官网https://mybatis.org/mybatis-3/zh/getting-started.html红色框框中的内容是需要根据自己的设置更改的我的sql映射文件 UserMapper.xml配置如下?xml version1.0 encodingUTF-8 ? !DOCTYPE mapperPUBLIC -//mybatis.org//DTD Mapper 3.0//ENhttp://mybatis.org/dtd/mybatis-3-mapper.dtd!--namespace:名称空间 -- mapper namespacetestselect idselectAll resultTypecom.itheima.Pojo.Userselect * from tb_user;/select /mapper5. 编码 首先创建User类包含表中的所有字段public class User {private Integer id;private String username;private String passWord;private String gender;private String addr;public User() {}public User(Integer id, String username, String passWord, String gender, String addr) {this.id id;this.username username;this.passWord passWord;this.gender gender;this.addr addr;}public Integer getId() {return id;}public void setId(Integer id) {this.id id;}public String getUsername() {return username;}public void setUsername(String username) {this.username username;}public String getPassWord() {return passWord;}public void setPassWord(String passWord) {this.passWord passWord;}public String getGender() {return gender;}public void setGender(String gender) {this.gender gender;}public String getAddr() {return addr;}public void setAddr(String addr) {this.addr addr;}Overridepublic String toString() {return User{ id id , username username \ , passWord passWord \ , gender gender \ , addr addr \ };} }测试类main方法public static void main(String[] args) throws Exception {//1.加载mybatis核心配置文件获取SqlSessionFactoryString resource mybatis-config.xml;InputStream inputStream Resources.getResourceAsStream(resource);SqlSessionFactory sqlSessionFactory new SqlSessionFactoryBuilder().build(inputStream);//2.获取SqlSession对象用它来执行sqlSqlSession sqlSession sqlSessionFactory.openSession();//3.执行sqlListUser users sqlSession.selectList(test.selectAll);System.out.println(users);//4.释放资源sqlSession.close();}