经过上一章的学习,咱们已经对SpringBoot有简单的入门,接下来咱们深刻学习一下SpringBoot,咱们知道任何一个网站的数据大多数都是动态的,也就是说数据是从数据库提取出来的,而非静态数据,那么咱们接下来就是要链接数据,如今咱们常常使用的数据库有MySQL数据库,Oracle数据库,Redis(非关系型数据库),Mongodb(非关系型数据库)等等。java
1)学会使用SpringBoot和MyBatis经过注解的方式操做数据库mysql
2)学会使用SpringBoot和MyBatis经过XML配置文件的方式操做数据库web
1)打开idea,Create New Projectspring
2)选择Spring Initializer,而后点击下一步sql
3)填写组织,坐标等信息,而后点击Next数据库
4)选择依赖Web,而后勾选Web,点击Next,而后一直点击Next,直到项目结构创建完成apache
5)项目结构搭好以后,咱们新建一些包有控制层,服务层,数据访问层,实体层,完整结构以下mybatis
6)因为咱们要使用MyBatis操做数据库,因此须要添加一些依赖,完整的pom.xml文件以下app
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.1.3.RELEASE</version> <relativePath/> <!-- lookup parent from repository --> </parent> <groupId>com.demo02</groupId> <artifactId>demo_02</artifactId> <version>0.0.1-SNAPSHOT</version> <name>demo_02</name> <description>Demo project for Spring Boot</description> <properties> <java.version>1.8</java.version> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <!--mybatis-spring适配器--> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>1.1.1</version> </dependency> <!--mysql驱动包--> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.30</version> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project>
7)接下来咱们须要新建数据库以及生成实体,数据的创建我就不重复多说了,说一下使用idea快速生成实体(Product),数据库的sql脚本以下框架
#建立商品信息表
create table product ( pid int primary key not null auto_increment COMMENT"商品编号", pname varchar(50) COMMENT"商品名称", pprice DECIMAL(10,2) COMMENT"商品价格", ptime varchar(50) COMMENT"入库时间", pcount int COMMENT"库存", pstatus int COMMENT"商品状态" #0 表明下架,1表明上架 )COMMENT"商品信息表" insert into product(pname,pprice,ptime,pcount,pstatus)VALUES ("苹果",11,"2019-10-1",11,1) SELECT * from product
8)Database表示要链接的数据库名称,User表示用户名称,Password表示密码,而后点击Ok,而后选择你要生成实体的目录,生成完成以后基本结构就搭建好了
9)Product实体代码以下
package com.ssm.entity;
/*
* 商品实体类
* */
public class Product { private long pid;//编号 private String pname;//名称 private double pprice;//价格 private String ptime;//入库时间 private long pcount;//数量 private long pstatus;//状态 //无参构造方法 public Product() {} //带参构造方法 public Product(long pid, String pname, double pprice, String ptime, long pcount, long pstatus) { this.pid = pid; this.pname = pname; this.pprice = pprice; this.ptime = ptime; this.pcount = pcount; this.pstatus = pstatus; } public long getPid() { return pid; } public void setPid(long pid) { this.pid = pid; } public String getPname() { return pname; } public void setPname(String pname) { this.pname = pname; } public double getPprice() { return pprice; } public void setPprice(double pprice) { this.pprice = pprice; } public String getPtime() { return ptime; } public void setPtime(String ptime) { this.ptime = ptime; } public long getPcount() { return pcount; } public void setPcount(long pcount) { this.pcount = pcount; } public long getPstatus() { return pstatus; } public void setPstatus(long pstatus) { this.pstatus = pstatus; } @Override public String toString() { return "Product{" + "pid=" + pid + ", pname='" + pname + '\'' + ", pprice=" + pprice + ", ptime='" + ptime + '\'' + ", pcount=" + pcount + ", pstatus=" + pstatus + '}'; } }
1)接下来,咱们就须要配置一下链接数据库的配置文件,在application.xml中进行配置,applicaion.xml文件以下
#链接数据库的驱动
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
#链接数据库的url
spring.datasource.url=jdbc:mysql://localhost:3306/ssm?characterEncoding=utf-8
#用户名
spring.datasource.username=root
#密码
spring.datasource.password=123456
2)如今咱们就能够操做数据库了,编写ProductDao,ProductService,ProductImple,ProductController以及配置SpringBoot主程序,因为咱们新建的包不是和SpringBoot主程序同级目录,因此没法扫描到(项目启动时,只有@SpringBootApplication 所在的包被扫描,启动类是MainApplication.java, 也就是MainApplication.java类所在的这个包,而其余的controller和service以及mapper在其余的包里,因此并无被扫描)因此咱们须要配置一下
3)ProductDao文件以下
package com.ssm.dao;
import com.ssm.entity.Product; import org.apache.ibatis.annotations.Select; import java.util.List; public interface ProductDao { @Select("select * from product") List<Product> findAllProduct(); }
4)ProductService文件以下
package com.ssm.service;
import com.ssm.entity.Product; import java.util.List; public interface ProductService { List<Product> findAllProduct(); }
5)ProductImple文件以下
package com.ssm.service.imple;
import com.ssm.dao.ProductDao; import com.ssm.entity.Product; import com.ssm.service.ProductService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; import java.util.List; @Service public class ProductImple implements ProductService { @Autowired private ProductDao productDao; @Override public List<Product> findAllProduct() { return productDao.findAllProduct(); } }
6)ProductController文件以下
package com.ssm.controller;
import com.ssm.entity.Product; import com.ssm.service.ProductService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RestController; import java.util.List; @RestController public class ProductController { @Autowired private ProductService productService; //查询所有的商品信息 @GetMapping("/product") public List<Product> findAllProduct(){ return productService.findAllProduct(); } }
7)SpringBoot主程序文件以下
package com.demo02.demo_02;
import org.mybatis.spring.annotation.MapperScan; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.context.annotation.ComponentScan; @SpringBootApplication @ComponentScan(basePackages = {"com.ssm.controller","com.ssm.service"}) @MapperScan(basePackages = {"com.ssm.dao"}) public class Demo02Application { public static void main(String[] args) { SpringApplication.run(Demo02Application.class, args); } }
8)点击运行,在地址栏输入localhost:8080/product,若是出现以下结果,那么恭喜你,第一种方式你已经学会了
1)如今咱们经过第二种方式操做数据库,咱们先将application.xml中的配置文件所有注释,而后新建applicaion.yml,为何要使用这种格式呢?由于这种方式方便简洁,官方也推荐咱们使用这种类型,这是一些的相关格式,
server:
port: 8801
eureka:
client:
registerWithEureka: false
fetchRegistry: false
serviceUrl:
defaultZone: http://localhost:8801/eureka/
2)applicaion.yml配置以下
spring:
datasource:
driver-class-name: com.mysql.jdbc.Driver
url: jdbc:mysql://localhost:3306/ssm?characterEncoding=utf-8
username: root
password: 123456
mybatis:
typeAliasesPackage: com.ssm.entity
mapperLocations: classpath:mapper/*Mapper.xml
3)咱们要经过xml的格式操做数据库也就是咱们须要写Mapper.xml文件,在src/main/resources新建Mapper文件夹,而后新建ProductMapper.xml
4)ProductMapper.xml文件以下
<?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.ssm.dao.ProductDao">
<!--查询所有商品信息-->
<select id="findAllProduct" resultType="product">
select * from product
</select>
</mapper>
5)ProductDao文件以下
package com.ssm.dao;
import com.ssm.entity.Product; import org.apache.ibatis.annotations.Select; import java.util.List; public interface ProductDao { // @Select("select * from product") List<Product> findAllProduct(); }
6)ProductService文件以下
package com.ssm.service;
import com.ssm.entity.Product; import java.util.List; public interface ProductService { List<Product> findAllProduct(); }
7)ProductImple文件以下
package com.ssm.service.imple;
import com.ssm.dao.ProductDao; import com.ssm.entity.Product; import com.ssm.service.ProductService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; import java.util.List; @Service public class ProductImple implements ProductService { @Autowired private ProductDao productDao; @Override public List<Product> findAllProduct() { return productDao.findAllProduct(); } }
8)ProductController文件以下
package com.ssm.controller;
import com.ssm.entity.Product; import com.ssm.service.ProductService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RestController; import java.util.List; @RestController public class ProductController { @Autowired private ProductService productService; //查询所有的商品信息 @GetMapping("/product") public List<Product> findAllProduct(){ return productService.findAllProduct(); } }
9)SpringBoot主程序文件以下
package com.demo02.demo_02;
import org.mybatis.spring.annotation.MapperScan; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.context.annotation.ComponentScan; @SpringBootApplication @ComponentScan(basePackages = {"com.ssm.controller","com.ssm.service"}) @MapperScan(basePackages = {"com.ssm.dao"}) public class Demo02Application { public static void main(String[] args) { SpringApplication.run(Demo02Application.class, args); } }
10)运行,结果和以前的同样
经过对本章的学习,咱们已经能够操做数据库了,相对SSM框架来讲,SpringBoot的确简化了咱们许多操做,当你须要哪些依赖时,咱们直接选择就能够,它也的确比较实在。也但愿你们能够和我多多交流。