一、generator简介
MyBatis Generator（MBG）是MyBatis MyBatis 和iBATIS的代码生成器。它将为所有版本的MyBatis以及版本2.2.0之后的iBATIS版本生成代码。它将内省数据库表（或许多表），并将生成可用于访问表的工件。这减少了设置对象和配置文件以与数据库表交互的初始麻烦。MBG寻求对简单CRUD（创建，检索，更新，删除）的大部分数据库操作产生重大影响。（一句话，generator可以自动生成代码和映射文件，但是多表查询还是需要我们去配置，即使这样也可以省很多功夫）
二、generator配置
generator官网
1.导包（后面跟mybatis整合，所以顺便把mybatis的包也导了）
1、.generator-config.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE generatorConfiguration
PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
"http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">
<generatorConfiguration>
<context id="mysqlTable" targetRuntime="MyBatis3">
<!-- 1.数据连接参数 -->
<jdbcConnection driverClass="com.mysql.jdbc.Driver"
connectionURL="jdbc:mysql://localhost:3306/ssm"
userId="root"
password="root">
</jdbcConnection>
<!-- 2.默认false，把JDBC DECIMAL 和 NUMERIC 类型解析为 Integer，为 true时把JDBC DECIMAL
和 NUMERIC 类型解析为java.math.BigDecimal -->
<javaTypeResolver >
<property name="forceBigDecimals" value="false" />
</javaTypeResolver>
<!-- 3.生成模型的位置 就是生成pojo的位置-->
<javaModelGenerator targetPackage="com.baidu.domain" targetProject="F:\\workJava\\day605\\day78_MGB\\src">
<!-- enableSubPackages:是否让schema作为包的后缀 -->
<property name="enableSubPackages" value="true" />
<property name="trimStrings" value="true" />
</javaModelGenerator>
<!-- 4.targetProject:mapper映射文件生成的位置 -->
<sqlMapGenerator targetPackage="com.baidu.mapper" targetProject="F:\\workJava\\day605\\day78_MGB\\src">
<!-- enableSubPackages:是否让schema作为包的后缀 -->
<property name="enableSubPackages" value="true" />
</sqlMapGenerator>
<!-- 5. targetPackage：mapper接口生成的位置 -->
<javaClientGenerator type="XMLMAPPER" targetPackage="com.baidu.mapper"
targetProject="F:\\workJava\\day605\\day78_MGB\\src">
<property name="enableSubPackages" value="true" />
</javaClientGenerator>
<!-- 6.要生成的表 -->
<table tableName="t_user"/>
<!--<table tableName="tb_user"/>-->
</context>
</generatorConfiguration>
2、启动generator
package gen;
import org.mybatis.generator.api.MyBatisGenerator;
import org.mybatis.generator.config.Configuration;
import org.mybatis.generator.config.xml.ConfigurationParser;
import org.mybatis.generator.internal.DefaultShellCallback;
import java.io.File;
import java.util.ArrayList;
import java.util.List;
/**
* 生成 domain和 mapper 文件夹和里面的所有代码
*/
public class Generator {
public static void main(String[] args) throws Exception{
List<String> warnings = new ArrayList<String>();
boolean overwrite = true;
File configFile = new File("F:\\workJava\\day605\\day78_MGB\\src\\generator.xml");
ConfigurationParser cp = new ConfigurationParser(warnings);
Configuration config = cp.parseConfiguration(configFile);
DefaultShellCallback callback = new DefaultShellCallback(overwrite);
MyBatisGenerator myBatisGenerator = new MyBatisGenerator(config,callback, warnings);
myBatisGenerator.generate(null);
}
}
三、与Spring和mybatis整合到一起
applicationContext.xml配置
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.0.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-4.0.xsd ">
<!-- spring核心配置文件-->
<!-- 加载配置文件 -->
<context:property-placeholder location="classpath:jdbc.properties" />
<!-- 数据库连接池 -->
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"
destroy-method="close">
<property name="driverClassName" value="${jdbc.driver}" />
<property name="url" value="${jdbc.url}" />
<property name="username" value="${jdbc.username}" />
<property name="password" value="${jdbc.password}" />
<property name="maxActive" value="10" />
<property name="maxIdle" value="5" />
</bean>
<!-- SqlsessionFactory -->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<!-- 数据源 -->
<property name="dataSource" ref="dataSource"/>
<!-- mybatis配置文件 -->
<property name="configLocation" value="classpath:SqlMapConfig.xml"/>
</bean>
<!--
MapperScannerConfigurer：mapper的扫描器，将包下边的mapper接口自动创建代理对象(bean)，
自动创建到spring容器中，bean的id是mapper的类名（首字母小写）
-->
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<!-- 配置扫描包的路径
如果要扫描多个包，中间使用半角逗号分隔
-->
<!-- 因为这里扫描了，所以mybatis(SqlMapConfig.xml)中的<mappers><package name="com.baidu.dao"/></mappers>就可以删除了-->
<property name="basePackage" value="com.baidu.mapper"></property>
<!-- 注意这里：使用sqlSessionFactoryBeanName -->
<property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"></property>
</bean>
</beans>
SqlMapConfig.xml(mybatis)配置
<?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>
<!-- pojo中的实体类起别名-->
<typeAliases>
<!--单独制定别名-->
<!-- <typeAlias type="com.com.baidu.pojo.User" alias="user"></typeAlias>-->
<!--实体类首字母大写或者小写均可，例如：user User-->
<package name="com.baidu.domain"/>
</typeAliases>
<!--
<mappers>
<package name="com.baidu.dao"/>
</mappers>
-->
</configuration>
jdbc.properties文件配置
log4j.properties文件配置
jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://127.0.0.1:3306/ssm?useUnicode=true&characterEncoding=utf-8
jdbc.username=root
jdbc.password=root
# Global logging configuration，建议开发环境中要用debug
log4j.rootLogger=DEBUG, stdout
# Console output...
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n
3.测试代码(简单测试了几个方法，generator提供了丰富的单表操作方法）
package com.baidu.test;
import com.baidu.domain.TUser;
import com.baidu.domain.TUserExample;
import com.baidu.mapper.TUserMapper;
import org.junit.Test;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import java.util.ArrayList;
import java.util.List;
public class TestMySp {
@Test
public void testMapper() throws Exception{
ClassPathXmlApplicationContext applicationContext = new ClassPathXmlApplicationContext("classpath:applicationContext.xml");
TUserMapper bean = applicationContext.getBean(TUserMapper.class);
TUserExample tUserExample = new TUserExample();
TUserExample.Criteria criteria = tUserExample.createCriteria();
/* criteria.andNameEqualTo("admin");
criteria.andAgeEqualTo(20);
System.out.println(bean.selectByExample(tUserExample));*/
//根据id集合查询用户信息
/* criteria.andIdBetween(1,60);
List<TUser> tUsers = bean.selectByExample(tUserExample);
tUsers.forEach(c->{
System.out.println(c);
});*/
//条件删除用户
ArrayList<Integer> list = new ArrayList<>();
list.add(65);
list.add(68);
criteria.andIdIn(list);
int count = bean.deleteByExample(tUserExample);
System.out.println(count);
}
}
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Test;
import com.mybatis_generator_demo.domain.TUser;
import com.mybatis_generator_demo.domain.TUserExample;
import com.mybatis_generator_demo.domain.TUserExample.Criteria;
import com.mybatis_generator_demo.mapper.TUserMapper;
public class TestMapper {
//条件删除用户
@Test
public void test_delete() {
try {
InputStream in = Resources.getResourceAsStream("sqlMapConfig.xml");
SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder();
SqlSessionFactory sqlSessionFactory = builder.build(in);
SqlSession session = sqlSessionFactory.openSession();
TUserMapper mapper = session.getMapper(TUserMapper.class);
TUserExample example = new TUserExample();
example.createCriteria().andUidBetween(50, 60);
int result = mapper.deleteByExample(example);
session.commit();
if(result>0) System.out.println("success");
else System.out.println("failure");
} catch (IOException e) {
e.printStackTrace();
}
}
//根据id集合查询用户信息
@Test
public void test_andUidIn() {
try {
InputStream in = Resources.getResourceAsStream("sqlMapConfig.xml");
SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder();
SqlSessionFactory sqlSessionFactory = builder.build(in);
SqlSession session = sqlSessionFactory.openSession();
TUserMapper mapper = session.getMapper(TUserMapper.class);
TUserExample example = new TUserExample();
List<Integer> list = new ArrayList<Integer>();
list.add(1);
list.add(5);
list.add(108);
list.add(53);
example.createCriteria().andUidIn(list);
List<TUser> users = mapper.selectByExample(example);
for (TUser tUser : users) {
System.out.println(tUser);
}
} catch (IOException e) {
e.printStackTrace();
}
}
//条件更新用户信息
@Test
public void test_updateByExample() {
try {
InputStream in = Resources.getResourceAsStream("sqlMapConfig.xml");
SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder();
SqlSessionFactory sqlSessionFactory = builder.build(in);
SqlSession session = sqlSessionFactory.openSession();
TUserMapper mapper = session.getMapper(TUserMapper.class);
TUserExample example = new TUserExample();
example.createCriteria().andUnameEqualTo("测试插入");
TUser u = new TUser();
u.setAddress("广东");
u.setAge(225);
u.setUname("李飞");
int result = mapper.updateByExampleSelective(u, example);
if(result>0) System.out.println("success");
else System.out.println("failure");
session.commit();
} catch (IOException e) {
e.printStackTrace();
}
}
//多条件or查询
@Test
public void test_selectByExample2() {
try {
InputStream in = Resources.getResourceAsStream("sqlMapConfig.xml");
SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder();
SqlSessionFactory sqlSessionFactory = builder.build(in);
SqlSession session = sqlSessionFactory.openSession();
TUserMapper mapper = session.getMapper(TUserMapper.class);
TUserExample example = new TUserExample();
example.createCriteria().andAgeBetween(1, 10).andAddressLike("%北京%");
Criteria c2 = example.createCriteria().andUnameEqualTo("老王");
example.or(c2);
List<TUser> list = mapper.selectByExample(example);
for (TUser tUser : list) {
System.out.println(tUser);
}
} catch (IOException e) {
e.printStackTrace();
}
}
//多条件and查询
@Test
public void test_selectByExample() {
try {
InputStream in = Resources.getResourceAsStream("sqlMapConfig.xml");
SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder();
SqlSessionFactory sqlSessionFactory = builder.build(in);
SqlSession session = sqlSessionFactory.openSession();
TUserMapper mapper = session.getMapper(TUserMapper.class);
TUserExample example = new TUserExample();
example.createCriteria().andAgeBetween(1, 10).andAddressLike("%北京%");
List<TUser> list = mapper.selectByExample(example);
for (TUser tUser : list) {
System.out.println(tUser);
}
} catch (IOException e) {
e.printStackTrace();
}
}
//插入用户到数据库
@Test
public void test_insert() {
try {
InputStream in = Resources.getResourceAsStream("sqlMapConfig.xml");
SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder();
SqlSessionFactory sqlSessionFactory = builder.build(in);
SqlSession session = sqlSessionFactory.openSession();
TUserMapper mapper = session.getMapper(TUserMapper.class);
TUser u = new TUser();
u.setAddress("四川");
u.setAge(22);
u.setUname("测试插入");
int result = mapper.insert(u);
if(result>0) System.out.println("success");
else System.out.println("failure");
session.commit();
} catch (IOException e) {
e.printStackTrace();
}
}
//根据主键获取用户信息
@Test
public void test_selectByPrimaryKey() {
try {
InputStream in = Resources.getResourceAsStream("sqlMapConfig.xml");
SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder();
SqlSessionFactory sqlSessionFactory = builder.build(in);
SqlSession session = sqlSessionFactory.openSession();
TUserMapper mapper = session.getMapper(TUserMapper.class);
TUser TUser = mapper.selectByPrimaryKey(3);
System.out.println(TUser);
} catch (IOException e) {
e.printStackTrace();
}
}
}
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