Spring全家桶系列一一SpringBoot与Mybatis结合
1. mapper.xml、dao接口、实体类自动生成
1.1 修改配置文件generator.xml
generator.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>
<!-- 数据库驱动包位置 也就是刚解压的文件的位置加上 mysql-connector-java-5.1.34.jar-->
<classPathEntry location="C:\resources\generator\mysql-connector-java-5.1.34.jar" />
<!--这里也适用Oracle数据库的自动生成-->
<!-- <classPathEntry location="C:\resources\generator\ojdbc6.jar" /> -->
<context id="DB2Tables" targetRuntime="MyBatis3">
<commentGenerator>
<!-- 去除生成日期 -->
<property name="suppressDate" value="true"/>
<!-- 去除所有的注解 -->
<property name="suppressAllComments" value="true"/>
</commentGenerator>
<!-- 数据库链接URL、用户名、密码 -->
<jdbcConnection driverClass="com.mysql.jdbc.Driver" connectionURL="jdbc:mysql://localhost:3306/ceilan" userId="root" password="123456">
<!-- <jdbcConnection driverClass="oracle.jdbc.driver.OracleDriver" connectionURL="jdbc:oracle:thin:@localhost:1521:orcl" userId="scott" password="tiger">-->
</jdbcConnection>
<!--java类型处理器-->
<javaTypeResolver>
<property name="forceBigDecimals" value="false" />
</javaTypeResolver>
<!-- 生成模型的包名和位置 -->
<javaModelGenerator targetPackage="com.example.entity" targetProject="C:\resources\generator\src">
<property name="enableSubPackages" value="true" />
<property name="trimStrings" value="true" />
</javaModelGenerator>
<!-- 生成的映射文件包名和位置 -->
<sqlMapGenerator targetPackage="mapping" targetProject="C:\resources\generator\src">
<property name="enableSubPackages" value="true" />
</sqlMapGenerator>
<!-- 生成DAO的包名和位置 -->
<javaClientGenerator type="XMLMAPPER" targetPackage="com.example.dao" targetProject="C:\resources\generator\src">
<property name="enableSubPackages" value="true" />
</javaClientGenerator>
<!-- 要生成哪个表,更改tableName(数据库里表名)和domainObjectName(实体名，一般首字母大写)就可以 -->
<table tableName="area" domainObjectName="Area" enableCountByExample="false" enableUpdateByExample="false" enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false" />
</context>
</generatorConfiguration>1.2 用Java运行自动生成
java -jar mybatis-generator-core-1.3.2.jar -configfile generator.xml -overwrite然后把当前目录src下的com文件夹拷贝到项目文件夹下
把mapping文件拷贝到resources文件夹下
目录结构如上
2.集成Mybatis框架
2.1 引入依赖
compile "mysql:mysql-connector-java:5.1.39"
compile 'org.mybatis.spring.boot:mybatis-spring-boot-starter:1.2.0'2.2 启动类DemoApplication.java增加扫描配置
package com.example;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.web.bind.annotation.RequestMapping;
@SpringBootApplication
// mapper接口 扫描包配置
@MapperScan(value = "com.example.dao")
public class DemoApplication {
public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
}2.3 添加项目首页index.html
index.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<h1>Welcome SpringBoot</h1>
</body>
</html>然后在 DemoApplication 启动类中添加
//欢迎页面 首页
@RequestMapping("/")
public String index(){
return "index";
}之前已经在application.yml中配置了资源映射设置,如下
spring:
mvc:
view:
suffix: .html
resources:
static-locations: classpath:/templates所以现在的项目启动访问 http://localhost:8080/ 是可以直接访问到首页的
3.添加业务层和控制层实现CRUD(增删改查)
增加业务逻辑层包service以及在其下增加impl包用来实现其接口
3.1业务逻辑层接口 AreaService.java
package com.example.service;
import com.example.entity.Area;
/**
* 这里给dao层的代码拷贝过来先使用
* created by cfa 2018-11-08 下午 9:56
**/
public interface AreaService {
int deleteByPrimaryKey(Integer id);
int insert(Area record);
int insertSelective(Area record);
Area selectByPrimaryKey(Integer id);
int updateByPrimaryKeySelective(Area record);
int updateByPrimaryKey(Area record);
}3.2业务层实现类 AreaServiceImpl.java
package com.example.service.impl;
import com.example.dao.AreaMapper;
import com.example.entity.Area;
import com.example.service.AreaService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.io.Serializable;
/**
* 这里的@Service注解相当于自动注册到Spring的Bean
* 相当于原来的Application.xml里的 <bean id="areaServiceImpl" class="com.example.service.impl.AreaServiceImpl"/>
* created by cfa 2018-11-08 下午 9:58
**/
@Service
public class AreaServiceImpl implements AreaService, Serializable {
private final AreaMapper areaMapper;
@Autowired
public AreaServiceImpl(AreaMapper areaMapper) {
this.areaMapper = areaMapper;
}
@Override
public int deleteByPrimaryKey(Integer id) {
return areaMapper.deleteByPrimaryKey(id);
}
@Override
public int insert(Area record) {
return areaMapper.insert(record);
}
@Override
public int insertSelective(Area record) {
return areaMapper.insertSelective(record);
}
@Override
public Area selectByPrimaryKey(Integer id) {
return areaMapper.selectByPrimaryKey(id);
}
@Override
public int updateByPrimaryKeySelective(Area record) {
return areaMapper.updateByPrimaryKeySelective(record);
}
@Override
public int updateByPrimaryKey(Area record) {
return areaMapper.updateByPrimaryKey(record);
}
}3.3控制层的AreaController.java
package com.example.controller;
import com.example.entity.Area;
import com.example.service.AreaService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
@RequestMapping("area")
public class AreaController {
private final AreaService areaService;
@Autowired
public AreaController(AreaService areaService) {
this.areaService = areaService;
}
@RequestMapping("query")
public Area areaList(){
return areaService.selectByPrimaryKey(1);
}
}看到这里，想必看到很多次@Autowired，@Service等注解了,这就是Spring的两大核心之一的IOC(Inversion of Control),也就是DI依赖注入；
Spring的两大核心AOP和IOC大家面试的时候也基本都有问到，到这里你IOC就不用头疼了；
业务层提供的接口加实现类就是为了实现松耦合，不然一个类就解决了，就像一个手机，坏了，里面的电池，屏幕，主板什么的拆下来还能用，这就是松耦合。