Springboot集成Mybatis、JPA

一、Springboot与Mybatis集成
1、思路 一是引入mybatis-starter使springboot与mybatis集成
二是完成连接数据库
（1）pom.xml 主要是引入mybatis-spring-boot-starter

<!-- mybatis新增 begin-->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter</artifactId>
</dependency>
<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>1.1.1</version>
</dependency>
 <dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
</dependency>
<!--mybatis  end -->

(2)application.properties 添加相关配置

#mybatis add
mybatis.type-aliases-package=com.neusoft.demo.domain
spring.datasource.driverClassName = com.mysql.cj.jdbc.Driver
spring.datasource.url = jdbc:mysql://localhost:3306/springboot?useUnicode=true&characterEncoding=utf-8&serverTimezone=UTC
spring.datasource.username = root
spring.datasource.password = root

（3）在启动类中添加对mapper包扫描@MapperScan

@SpringBootApplication
@MapperScan("com.neusoft.demo.mapper")
public class DemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }
}

(4)新建UserController

package com.neusoft.demo.controller;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import com.neusoft.demo.domain.User;
import com.neusoft.demo.service.UserService;

@RestController
@RequestMapping("/user")
public class UserController {
    @Autowired
    UserService userService;
    @RequestMapping("/findAll")
    public List<User> findAll(){
        return userService.findAll();
    }

}

 

（5）新建Service接口和实现类

package com.neusoft.demo.service;

import java.util.List;

import com.neusoft.demo.domain.User;

public interface UserService {
    List<User> findAll();

}

package com.neusoft.demo.service;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.neusoft.demo.domain.User;
import com.neusoft.demo.mapper.UserMapper;

@Service
public class UserServiceImpl implements UserService{
    @Autowired
    UserMapper userMapper;

    @Override
    public List<User> findAll() {
        // TODO Auto-generated method stub
        return userMapper.findAll();
    }

}

（6）新建UserMapper接口

package com.neusoft.demo.mapper;

import java.util.List;

import org.apache.ibatis.annotations.Select;

import com.neusoft.demo.domain.User;

public interface UserMapper {
    @Select("select id,name from user")
    List<User> findAll();

}

（7）新建表user，varchar类型id和name
二、springboot与jpa集成
1、添加依赖

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
</dependency>

2、配置数据源和JPA
配置数据源，在application.properties文件中加入如下信息

spring.datasource.driverClassName = com.mysql.cj.jdbc.Driver
spring.datasource.url = jdbc:mysql://localhost:3306/springboot?useUnicode=true&characterEncoding=utf-8&serverTimezone=UTC
spring.datasource.username = root
spring.datasource.password = root
spring.datasource.tomcat.max-active=20

配置JPA，在application.properties配置文件中加入如下信息

#连接哪种数据库
spring.jpa.database=mysql
#查询过程中日志里是否显示查询语句
spring.jpa.show-sql=true
#自动根据实体创建表
spring.jpa.hibernate.ddl-auto=update

配置说明

ddl-auto:create----每次运行该程序，没有表格会新建表格，表内有数据会清空
ddl-auto:create-drop----每次程序结束的时候会清空表
ddl-auto:update----每次运行程序，没有表格会新建表格，表内有数据不会清空，只会更新
ddl-auto:validate----运行程序会校验数据与数据库的字段类型是否相同，不同会报错
3、创建实体类

package com.neusoft.demo.domain;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;

import org.hibernate.annotations.GenericGenerator;

@Entity
@Table(name="person")
@GenericGenerator(name="jpa-uuid",strategy="uuid")
public class Person {
    @Id
    @GeneratedValue(generator="jpa-uuid")
    @Column(length=32)
    private String id;
    @Column(name="name",nullable=true,length=20)
    private String name;
    @Column(name="age",nullable=true,length=4)
    private int age;
    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }

}

4、创建接口

package com.neusoft.demo.dao;

import org.springframework.data.jpa.repository.JpaRepository;

import com.neusoft.demo.domain.Person;

public interface PersonRepository extends JpaRepository<Person, String>{

}

5、创建controller

package com.neusoft.demo.controller;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import com.neusoft.demo.dao.PersonRepository;
import com.neusoft.demo.domain.Person;

@RestController
@RequestMapping("/person")
public class JPAController {
    @Autowired
    PersonRepository personRepository;
    @RequestMapping("/add")
    public String addPerson(Person person) {
        personRepository.save(person);
        return "success";
    }
    @RequestMapping("/update")
    public String updatePerson(Person person) {
        personRepository.save(person);
        return "success";
    }
    @RequestMapping("/del")
    public String delPerson(String id) {
        personRepository.deleteById(id);
        return "success";
    }
    @RequestMapping("/findAll")
    public List<Person> findPerson() {
        return personRepository.findAll();
    }

}