Springboot
1.springboot自动装配原理
我们在使用springboot时,并没有像之前项目加载我们的前端控制DispatcherServlet,也没有写编码过滤器。但是springboot可以完成请求以及编码的设置。
原理: 主启动类上的@SpringBootApplication注解上,而该注解是一个复合组件,而在复合注解中存在@EnableAutoConfiguration, 这个@EnableAutoConfiguration注解也是一个复合注解,包含@Import—而@Import注解导入一个AutoConfigurationImportSelector 【自动配置选择器】,在该类中存在一个方法getAutoConfigurationEntry --作用:得到自动配置类的实体。而这些自动配置类会完成相应的自动装配。
2.springboot整合数据源–连接数据库
2.1 设置默认数据源
(1)引入相关依赖
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>
springboot自动配置会加载jdbc的自动配置类—读取springboot配置文件中数据源的信息,从而完成数据源的自动配置。
(2)application配置文件中配置数据源.
# 数据库版本8.0之前的不用加cj 8.0及以后加cj
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.username=账号
spring.datasource.password=密码
spring.datasource.url=jdbc:mysql://localhost:3306/库名?serverTimezone=Asia/Shanghai
(3)测试
@SpringBootTest
class Springboot02ApplicationTests {
//springboot帮你完成数据源的自动装配
@Autowired
private DataSource dataSource;
@Test
void contextLoads() throws SQLException {
System.out.println(dataSource.getConnection());
}
2.2 设置Druid数据源
(1)导入druid数据源的依赖
<!--druid数据源的依赖-->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid-spring-boot-starter</artifactId>
<version>1.2.1</version>
</dependency>
(2)修改配置文件
spring.datasource.druid.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.druid.username=账号
spring.datasource.druid.password=密码
spring.datasource.druid.url=jdbc:mysql://localhost:3306/库名?serverTimezone=Asia/Shanghai
#初始化的连接对象的个数
spring.datasource.druid.initial-size=5
#最多的连接数
spring.datasource.druid.max-active=10
(3)测试:
class Springboot02ApplicationTests {
//springboot帮你完成数据源的自动装配
@Autowired
private DataSource dataSource;
@Test
void contextLoads() throws SQLException {
System.out.println(dataSource);
}
3.springboot整合mybatis框架
ssm===>spring框架需要配置SqlSesssionFactoryBean对象,还有配置DAO接口的代理实现类。
springboot会自动配置SqlSesssionFactoryBean对象,必须引入starter依赖
准备:
表
/*
Navicat Premium Data Transfer
Source Server : wzy
Source Server Type : MySQL
Source Server Version : 80025
Source Host : localhost:3306
Source Schema : diyige
Target Server Type : MySQL
Target Server Version : 80025
File Encoding : 65001
Date: 19/08/2023 09:37:37
*/
SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;
-- ----------------------------
-- Table structure for user
-- ----------------------------
DROP TABLE IF EXISTS `user`;
CREATE TABLE `user` (
`id` int(0) NOT NULL AUTO_INCREMENT COMMENT '主键ID',
`name` varchar(30) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NULL DEFAULT NULL COMMENT '姓名',
`age` int(0) NULL DEFAULT NULL COMMENT '年龄',
`email` varchar(50) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NULL DEFAULT NULL COMMENT '邮箱',
PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8mb4 COLLATE = utf8mb4_0900_ai_ci ROW_FORMAT = Dynamic;
-- ----------------------------
-- Records of user
-- ----------------------------
INSERT INTO `user` VALUES (1, 'Jone', 18, 'test1@baomidou.com');
INSERT INTO `user` VALUES (2, 'Jack', 20, 'test2@baomidou.com');
INSERT INTO `user` VALUES (3, 'Tom', 28, 'test3@baomidou.com');
INSERT INTO `user` VALUES (4, 'Sandy', 21, 'test4@baomidou.com');
INSERT INTO `user` VALUES (5, 'Billie', 24, 'test5@baomidou.com');
SET FOREIGN_KEY_CHECKS = 1;
依赖
<!--mybatis和springboot整合的依赖-->
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>2.1.0</version>
</dependency>
实体类
package com.aaa.entity;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
@Data
@AllArgsConstructor
@NoArgsConstructor
public class User {
private Integer id;
private String name;
private Integer age;
private String email;
}
dao接口
public interface UserDao {
public List<User> findAll();
}
mapper映射文件
<?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">
<mapper namespace="com.aaa.dao.UserDao">
<select id="findAll" resultType="com.aaa.entity.User">
select * from user
</select>
</mapper>
修改配置文件的内容
#设置Druid数据源
spring.datasource.druid.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.druid.username=root
spring.datasource.druid.password=123456
spring.datasource.druid.url=jdbc:mysql://localhost:3306/diyige?serverTimezone=Asia/Shanghai
#初始化的连接对象的个数
spring.datasource.druid.initial-size=5
#最多的连接数
spring.datasource.druid.max-active=10
#指定映射文件所在的路径
mybatis.mapper-locations=classpath:/mapper/*.xml
在主启动类上dao接口的扫描配置
测试
@Autowired
private UserDao userDao;
@Test
public void testFindAll(){
List<User> all = userDao.findAll();
System.out.println(all);
}
4.springboot整合pageHelper分页插件
导入pageHelper的依赖
<dependency>
<groupId>com.github.pagehelper</groupId>
<artifactId>pagehelper-spring-boot-starter</artifactId>
<version>1.4.5</version>
</dependency>
测试:
@Test
public void testFindAll(){
//拦截器: select * from t_user
PageHelper.startPage(1,2);
List<User> all = userDao.findAll();
//把查询的结果封装到PageInfo类中
PageInfo<User> pageInfo=new PageInfo<>(all);
System.out.println("总条数:"+pageInfo.getTotal());
System.out.println("总页数:"+pageInfo.getPages());
System.out.println("当前页的记录:"+pageInfo.getList());
}
5. 综合案例
springboot+mybatis+druid+pageHelper: CRUD
(1)创建springboot工程并引入相关的依赖
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>2.3.1</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid-spring-boot-starter</artifactId>
<version>1.2.1</version>
</dependency>
<dependency>
<groupId>com.github.pagehelper</groupId>
<artifactId>pagehelper-spring-boot-starter</artifactId>
<version>1.4.5</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
(2)修改配置文件
#数据源
spring.datasource.druid.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.druid.username=账号
spring.datasource.druid.password=密码
spring.datasource.druid.url=jdbc:mysql://localhost:3306/库名?serverTimezone=Asia/Shanghai
spring.datasource.druid.initial-size=5
spring.datasource.druid.max-active=10
#mybatis映射文件的路径
mybatis.mapper-locations=classpath:/mapper/*.xml
(3)表
/*
Navicat Premium Data Transfer
Source Server : wzy
Source Server Type : MySQL
Source Server Version : 80025
Source Host : localhost:3306
Source Schema : diyige
Target Server Type : MySQL
Target Server Version : 80025
File Encoding : 65001
Date: 19/08/2023 10:54:53
*/
SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;
-- ----------------------------
-- Table structure for student
-- ----------------------------
DROP TABLE IF EXISTS `student`;
CREATE TABLE `student` (
`id` int(0) UNSIGNED NOT NULL AUTO_INCREMENT,
`picture` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NULL DEFAULT NULL,
`name` varchar(20) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NULL DEFAULT NULL,
`age` int(0) NULL DEFAULT NULL,
`sex` varchar(1) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NULL DEFAULT NULL,
`birthday` date NULL DEFAULT NULL,
`clazz_id` int(0) NULL DEFAULT NULL,
PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 15 CHARACTER SET = utf8mb4 COLLATE = utf8mb4_0900_ai_ci ROW_FORMAT = Dynamic;
SET FOREIGN_KEY_CHECKS = 1;
/*
Navicat Premium Data Transfer
Source Server : wzy
Source Server Type : MySQL
Source Server Version : 80025
Source Host : localhost:3306
Source Schema : diyige
Target Server Type : MySQL
Target Server Version : 80025
File Encoding : 65001
Date: 19/08/2023 10:55:04
*/
SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;
-- ----------------------------
-- Table structure for clazz
-- ----------------------------
DROP TABLE IF EXISTS `clazz`;
CREATE TABLE `clazz` (
`cid` int(0) UNSIGNED NOT NULL AUTO_INCREMENT,
`clazz_name` varchar(20) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NULL DEFAULT NULL,
PRIMARY KEY (`cid`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 3 CHARACTER SET = utf8mb4 COLLATE = utf8mb4_0900_ai_ci ROW_FORMAT = Dynamic;
SET FOREIGN_KEY_CHECKS = 1;
(4)实体类:
student
package com.aaa.entity;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import java.util.Date;
@Data
@AllArgsConstructor
@NoArgsConstructor
public class Student {
private Integer id;
private String picture;
private String name;
private Integer age;
private String sex;
private Date birthday;
private Integer clazzId;
private Clazz clazz;
}
clazz
package com.aaa.entity;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
@Data
@AllArgsConstructor
@NoArgsConstructor
public class Clazz {
private Integer cid;
private String clazzName;
}
(5)dao接口和映射文件
package com.aaa.dao;
import com.aaa.entity.Student;
import java.util.List;
public interface StudentDao {
/**
* 增加
* @param student
* @return
*/
public int insert(Student student);
/**
* 删除
* @param id
* @return
*/
public int deleteById(Integer id);
/**
* 修改
* @param student
* @return
*/
public int update(Student student);
/**
* 根据id查询学生信息
* @param id
* @return
*/
public Student selectById(Integer id);
/**
* 查询所有
* @return
*/
public List<Student> selectAll();
}
<?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">
<mapper namespace="com.aaa.dao.StudentDao">
<!--返回添加时数据库生成的主键值-->
<insert id="insert" useGeneratedKeys="true" keyProperty="id">
insert into student values(null,#{picture},#{name},#{age},#{sex},#{birthday},#{clazzId})
</insert>
<update id="update">
update student set picture=#{picture},name=#{name},age=#{age},sex=#{sex},birthday=#{birthday},clazz_id=#{clazzId}
where id=#{id}
</update>
<delete id="deleteById">
delete from student where id=#{id}
</delete>
<resultMap id="student" type="com.aaa.entity.Student" autoMapping="true">
<id property="id" column="id"/>
<result property="clazzId" column="clazz_id"/>
<association property="clazz" javaType="com.aaa.entity.Clazz" autoMapping="true">
<id property="cid" column="cid"/>
<result property="clazzName" column="clazz_name"/>
</association>
</resultMap>
<select id="selectById" resultMap="student">
select * from student where id=#{id}
</select>
<select id="selectAll" resultMap="student">
select * from student s join clazz c on s.clazz_id=c.cid
</select>
</mapper>
(6)service业务层
package com.aaa.service;
import com.aaa.entity.Student;
import com.aaa.vo.Result;
public interface StudentService {
public Result deleteById(Integer id);
public Result update(Student student);
public Result insert(Student student);
public Result findById(Integer id);
public Result findAll(Integer current,Integer pageSize);
}
package com.aaa.service.impl;
import com.aaa.dao.StudentDao;
import com.aaa.entity.Student;
import com.aaa.service.StudentService;
import com.aaa.vo.Result;
import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;
@Service
public class StudentServiceImpl implements StudentService {
@Autowired
private StudentDao studentDao;
@Override
public Result deleteById(Integer id) {
int deleteById = studentDao.deleteById(id);
return deleteById>0?new Result(200,"删除成功",null):new Result(500,"删除失败",null);
}
@Override
public Result update(Student student) {
int update = studentDao.update(student);
return update>0?new Result(200,"修改成功",null):new Result(500,"修改失败",null);
}
@Override
public Result insert(Student student) {
int insert = studentDao.insert(student);
return insert>0?new Result(200,"添加成功",null):new Result(500,"添加失败",null);
}
@Override
public Result findById(Integer id) {
Student student = studentDao.selectById(id);
return new Result(200,"查询成功",student);
}
@Override
public Result findAll(Integer current, Integer pageSize) {
PageHelper.startPage(current,pageSize);
List<Student> students = studentDao.selectAll();
PageInfo<Student> pageInfo=new PageInfo<>(students);
return new Result(200,"查询成功",pageInfo);
}
}
(7)controller接口层
package com.aaa.controller;
import com.aaa.entity.Student;
import com.aaa.service.StudentService;
import com.aaa.vo.Result;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
@RestController
@RequestMapping("/student")
public class StudentController {
@Autowired
private StudentService studentService;
@DeleteMapping
public Result deleteById(Integer id){
return studentService.deleteById(id);
}
@PostMapping
public Result insert(@RequestBody Student student){
return studentService.insert(student);
}
@PutMapping
public Result update(@RequestBody Student student){
return studentService.update(student);
}
@GetMapping
public Result getById(Integer id){
return studentService.findById(id);
}
@GetMapping("/getAll")
public Result getAll(Integer current,Integer pageSize){
return studentService.findAll(current, pageSize);
}
}
(8)postman测试
6. springboot整合定时器。
可以在规定的时间内执行相应的代码。
比如: OSS文件上传—OSS的文件冗余的文件。----OSS的浪费。---->指定的时间自动删除。[夜间删除]
比如: 下单—>30分钟未支付—取消订单。
(1)引入定时器的依赖
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-quartz</artifactId>
</dependency>
(2)编写定义的业务代码
@Component
public class My {
@Autowired
private EmpDao empDao;
//定时任务执行的代码
@Scheduled(cron = "0 0 2 * * ?")
public void show(){
System.out.println("~~~~~~~~~~~~~~~~~~~~~~~~~~");
//可以写自己的写完代码
empDao.delete();
}
}
(3)开启定时的注解驱动
本文详细介绍了Springboot的自动装配原理,如何配置默认和Druid数据源,整合MyBatis框架、PageHelper分页插件,以及如何使用定时器。涵盖了从基础配置到实际案例的全方位内容。




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