SpringBoot 操作Mysql数据库

1项目目录结构

2 pom.xml

<?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>

    <groupId>com.china</groupId>
    <artifactId>shanghai</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>shanghai</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.0.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-actuator -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
            <version>2.1.0.RELEASE</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-web -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <version>2.1.0.RELEASE</version>
        </dependency>


        <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-test -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <version>2.1.0.RELEASE</version>
            <scope>test</scope>
        </dependency>


        <!-- https://mvnrepository.com/artifact/org.mybatis.spring.boot/mybatis-spring-boot-starter -->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.2</version>
        </dependency>



        <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.13</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <version>2.1.0.RELEASE</version>
            </plugin>
        </plugins>
    </build>


</project>

3 Customer.java

package com.china.shanghai.pojo;

public class Customer {
    private Integer id;
    private String username;
    private String jobs;
    private String phone;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getJobs() {
        return jobs;
    }

    public void setJobs(String jobs) {
        this.jobs = jobs;
    }

    public String getPhone() {
        return phone;
    }

    public void setPhone(String phone) {
        this.phone = phone;
    }
}

4 CustomerMapper.java

package com.china.shanghai.dao;


import com.china.shanghai.pojo.Customer;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;

import java.util.List;

@Mapper
public interface CustomerMapper {
    @Select("select * from customer where id=#{id}")
    public List<Customer> getCustomer(int id);
}

5 CustomerService.java

package com.china.shanghai.service;

import com.china.shanghai.pojo.Customer;

import java.util.List;

public interface CustomerService {
    public List<Customer> getCustomer(int id);
}

6CustomerServiceImpl.java

package com.china.shanghai.service.impl;

import com.china.shanghai.dao.CustomerMapper;
import com.china.shanghai.pojo.Customer;
import com.china.shanghai.service.CustomerService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
class CustomerServiceImpl implements CustomerService{
    @Autowired
    CustomerMapper customerMapper;

    @Override
    public List<Customer> getCustomer(int id) {
        return customerMapper.getCustomer(id);
    }
}

7CustomerController.java

package com.china.shanghai.controller;

import com.china.shanghai.pojo.Customer;
import com.china.shanghai.service.CustomerService;
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 CustomerController {
    @Autowired
    CustomerService customerService;
    @GetMapping("/findCustomerById")
    public List<Customer> getCustomer(int id){
        return customerService.getCustomer(id);
    }
}

8 application.properties

spring.datasource.url=jdbc:mysql://localhost:3306/mybatis?serverTimezone=UTC
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

9 ShanghaiApplication.java

package com.china.shanghai;

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.china.shanghai.controller","com.china.shanghai.service"})
@MapperScan(basePackages = "com.china.shanghai.dao")
public class ShanghaiApplication {

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

10 http://localhost:8080/findCustomerById?id=2