SpringCloud整合mybatis

快速搭建SpringCloud+mybatis项目

开发工具和环境

开发工具使用IntelliJ IDEA
JDK版本1.8
maven版本apache-maven-3.6.3
数据库使用MariaDB 10.5(用mysql也一样，注意下版本)
mybatis-spring-boot-starter 2.1.0

项目搭建

1.新建maven项目，SpringCloud顶级工程

pom.xml添加相关依赖
工程采用pom打包方式

<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>4.0.0modelVersion>

    <groupId>com.dbgroupId>
    <artifactId>springboot-mybatisartifactId>
    <version>1.0-SNAPSHOTversion>


    <packaging>pompackaging>

    <parent>
        <groupId>org.springframework.bootgroupId>
        <artifactId>spring-boot-starter-parentartifactId>
        <version>2.2.5.RELEASEversion>
        <relativePath />
    parent>

    <properties>
        

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

        <mysql-connector-java.version>5.1.41mysql-connector-java.version>
        <mybatis-spring-boot-starter.version>2.1.0mybatis-spring-boot-starter.version>
        <mapper-spring-boot-starter.version>2.1.5mapper-spring-boot-starter.version>
        <pagehelper-spring-boot-starter.version>1.2.12pagehelper-spring-boot-starter.version>
        <fastjson-version>1.2.66fastjson-version>
    properties>

    <dependencyManagement>
        <dependencies>
            
            <dependency>
                <groupId>org.springframework.cloudgroupId>
                <artifactId>spring-cloud-dependenciesartifactId>
                <version>Hoxton.SR3version>
                <type>pomtype>
                <scope>importscope>
            dependency>

            
            <dependency>
                <groupId>mysqlgroupId>
                <artifactId>mysql-connector-javaartifactId>
                <version>${mysql-connector-java.version}version>
            dependency>
            
            <dependency>
                <groupId>org.mybatis.spring.bootgroupId>
                <artifactId>mybatis-spring-boot-starterartifactId>
                <version>${mybatis-spring-boot-starter.version}version>
            dependency>
            
            <dependency>
                <groupId>tk.mybatisgroupId>
                <artifactId>mapper-spring-boot-starterartifactId>
                <version>${mapper-spring-boot-starter.version}version>
            dependency>
            
            <dependency>
                <groupId>com.github.pagehelpergroupId>
                <artifactId>pagehelper-spring-boot-starterartifactId>
                <version>${pagehelper-spring-boot-starter.version}version>
            dependency>
            
            <dependency>
                <groupId>com.alibabagroupId>
                <artifactId>fastjsonartifactId>
                <version>${fastjson-version}version>
            dependency>
        dependencies>
    dependencyManagement>

    <build>
        <finalName>${project.artifactId}finalName>
        <plugins>
            
            <plugin>
                <groupId>org.apache.maven.pluginsgroupId>
                <artifactId>maven-compiler-pluginartifactId>
                <version>3.8.1version>
                <configuration>
                    <source>1.8source>
                    <target>1.8target>
                    <encoding>UTF-8encoding>
                configuration>
            plugin>
        plugins>
    build>


project>

顶级工程建好后，建子工程(module)

pom.xml引入springboot、mysql、mybatis等依赖

<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">
    <parent>
        <artifactId>springboot-mybatisartifactId>
        <groupId>com.dbgroupId>
        <version>1.0-SNAPSHOTversion>
    parent>
    <modelVersion>4.0.0modelVersion>

    <artifactId>mybatis-integrateartifactId>

    <properties>
        <maven.compiler.source>8maven.compiler.source>
        <maven.compiler.target>8maven.compiler.target>
    properties>

    <dependencies>
        
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starterartifactId>
        dependency>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-webartifactId>
        dependency>


        
        <dependency>
            <groupId>mysqlgroupId>
            <artifactId>mysql-connector-javaartifactId>
        dependency>
        
        <dependency>
            <groupId>org.mybatis.spring.bootgroupId>
            <artifactId>mybatis-spring-boot-starterartifactId>
        dependency>
        
        <dependency>
            <groupId>tk.mybatisgroupId>
            <artifactId>mapper-spring-boot-starterartifactId>
        dependency>
        
        <dependency>
            <groupId>com.github.pagehelpergroupId>
            <artifactId>pagehelper-spring-boot-starterartifactId>
        dependency>

        <dependency>
            <groupId>com.alibabagroupId>
            <artifactId>fastjsonartifactId>
        dependency>
    dependencies>

project>

子工程配置应用端口和数据库相关信息

在resources下新建application.yml

#配置tomcat服务器端口等信息
server:
  port: 8090
  tomcat:
    uri-encoding: utf-8

#配置应用项目信息
spring:
  application:
    name: mybatis-test
  datasource: # 数据源的相关配置
    type: com.zaxxer.hikari.HikariDataSource          # 数据源类型：HikariCP
    driver-class-name: com.mysql.jdbc.Driver          # mysql驱动
    url: jdbc:mysql://localhost:3306/springcloud?useUnicode=true&characterEncoding=UTF-8&autoReconnect=true
    username: root
    password: admin
    hikari:
      connection-timeout: 30000       # 等待连接池分配连接的最大时长（毫秒），超过这个时长还没可用的连接则发生SQLException， 默认:30秒
      minimum-idle: 5                 # 最小连接数
      maximum-pool-size: 20           # 最大连接数
      auto-commit: true               # 自动提交
      idle-timeout: 600000            # 连接超时的最大时长（毫秒），超时则被释放（retired），默认:10分钟
      pool-name: DateSourceHikariCP     # 连接池名字
      max-lifetime: 1800000           # 连接的生命时长（毫秒），超时而且没被使用则被释放（retired），默认:30分钟 1800000ms
      connection-test-query: SELECT 1

应用代码实现

mybatis需要的pojo实体类、Mapper接口、mapper.xml sql映射文件可通过tk-mybatis-generator逆向工具生成后复制过来，具体操作可见
tk-mybatis-generator逆向生成工具使用

package com.db.mapper;

import tk.mybatis.mapper.common.Mapper;
import tk.mybatis.mapper.common.MySqlMapper;

public interface MyMapper<T> extends Mapper<T>, MySqlMapper<T> {
}

package com.db.pojo;

import javax.persistence.Column;
import javax.persistence.Id;
import javax.persistence.Table;
import java.util.Date;

@Table(name = "app_user")
public class AppUser {
    @Id
    private Integer id;

    private String userid;

    private String username;

    @Column(name = "created_time")
    private Date createdTime;

    /**
     * @return id
     */
    public Integer getId() {
        return id;
    }

    /**
     * @param id
     */
    public void setId(Integer id) {
        this.id = id;
    }

    /**
     * @return userid
     */
    public String getUserid() {
        return userid;
    }

    /**
     * @param userid
     */
    public void setUserid(String userid) {
        this.userid = userid;
    }

    /**
     * @return username
     */
    public String getUsername() {
        return username;
    }

    /**
     * @param username
     */
    public void setUsername(String username) {
        this.username = username;
    }

    /**
     * @return created_time
     */
    public Date getCreatedTime() {
        return createdTime;
    }

    /**
     * @param createdTime
     */
    public void setCreatedTime(Date createdTime) {
        this.createdTime = createdTime;
    }
}

package com.db.user.mapper;

import com.db.mapper.MyMapper;
import com.db.pojo.AppUser;
import org.springframework.stereotype.Repository;

@Repository
public interface AppUserMapper extends MyMapper<AppUser> {
}

新建springboot项目启动类Application.java

package com.db;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;
import tk.mybatis.spring.annotation.MapperScan;

@SpringBootApplication
@MapperScan(basePackages = "com.db.user.mapper")
//@ComponentScan(basePackages = {"com.db"})
public class Application {

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

MapperScan配置的扫包路径不要弄错。
ComponentScan根据自己启动类所有的目录确定是否需要加。由于我的启动类就是在com.db下，这里不需要添加，如果加上，idea也会提示这样加是多余的，需要删除。
如果启动类在com.db.service，项目启动又需要扫描到整个项目注解内容，即注解能被spring容器扫描到，则在启动类加上@ComponentScan(basePackages = {“com.db”})

下面开始编写业务层代码，包括前端请求需要的controller和业务处理service

新建service包，编写相关接口和实现

package com.db.service;



import com.db.pojo.AppUser;

import java.util.List;

public interface UserService {
    /**
     * 根据用户id查询用户信息
     */
    public AppUser getUser(String userId);
    /**
     * 查询所有用户信息，可实现分页
     */
    public List<AppUser> getAllUser(Integer page,
                                  Integer pageSize);
}

实现类添加@Service注解，这样能被spring容器扫描到，注入该bean

package com.db.service.impl;

import com.db.pojo.AppUser;
import com.db.service.UserService;
import com.db.user.mapper.AppUserMapper;
import com.github.pagehelper.PageHelper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import tk.mybatis.mapper.entity.Example;

import java.util.List;

@Service
public class UserServiceImpl implements UserService {

    @Autowired
    private AppUserMapper appUserMapper;

    @Override
    public AppUser getUser(String userId) {
        AppUser user = new AppUser();
        user.setUserid(userId);

        List<AppUser> userList = appUserMapper.select(user);
        return userList.get(0);
    }

    @Override
    public List<AppUser> getAllUser(Integer page, Integer pageSize) {
        Example example = new Example(AppUser.class);
        example.orderBy("createdTime").desc();
        Example.Criteria criteria = example.createCriteria();
//        criteria.andEqualTo("userid","");

        PageHelper.startPage(page, pageSize);
        List<AppUser> userList = appUserMapper.selectByExample(example);
        return userList;
    }
}

编写controller相关接口和实现

package com.db.controller.api;


import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;

@RequestMapping("user")
public interface UserControllerApi {
    @GetMapping("/getUserInfoByUserId")
    public Object getUserInfoByUserId(@RequestParam String userId);
    @GetMapping("/getAllUserInfo")
    public Object getAllUserInfo(@RequestParam Integer page,
                                 @RequestParam Integer pageSize);
}

package com.db.controller.api.impl;

import com.alibaba.fastjson.JSON;
import com.db.controller.api.UserControllerApi;
import com.db.pojo.AppUser;
import com.db.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
public class UserControllerImpl implements UserControllerApi {
    @Autowired
    private UserService userService;

    @Override
    public Object getUserInfoByUserId(String userId) {
        AppUser userInfo = userService.getUser(userId);
        System.out.println(JSON.toJSON(userInfo));
        return userInfo;
    }

    @Override
    public Object getAllUserInfo(Integer page,Integer pageSize) {
        List<AppUser> userList = userService.getAllUser(page,pageSize);
        System.out.println(JSON.toJSON(userList));
        return userList;
    }
}

测试

浏览器输入地址
http://localhost:8090/user/getUserInfoByUserId?userId=1002

后台控制台打印

http://localhost:8090/user/getAllUserInfo?page=1&pageSize=3

后台控制台打印

完成！！！！