springboot2.0 Mybatis 整合

原文:https://blog.csdn.net/Winter_chen001/article/details/80010967

环境/版本一览：

开发工具：Intellij IDEA 2017.1.3
springboot: 2.0.1.RELEASE
jdk：1.8.0_40
maven:3.3.9
alibaba Druid 数据库连接池：1.1.9

额外功能：

PageHelper 分页插件
mybatis generator 自动生成代码插件（本次搭建就不讲解了，请参照Spring boot Mybatis 整合（完整版））

开始搭建：

创建项目：

添加基础的依赖：

依赖文件：

按照pom文件补齐需要的依赖：

<?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.winterchen</groupId> <artifactId>springboot2-mybatis-demo</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>springboot2-mybatis-demo</name> <description>Demo project for Spring Boot</description> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.0.1.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> <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>1.3.2</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <scope>runtime</scope> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>org.apache.commons</groupId> <artifactId>commons-lang3</artifactId> <version>3.4</version> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-core</artifactId> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> </dependency> <dependency> <groupId>com.fasterxml.jackson.datatype</groupId> <artifactId>jackson-datatype-joda</artifactId> </dependency> <dependency> <groupId>com.fasterxml.jackson.module</groupId> <artifactId>jackson-module-parameter-names</artifactId> </dependency> <!-- 分页插件 --> <dependency> <groupId>com.github.pagehelper</groupId> <artifactId>pagehelper-spring-boot-starter</artifactId> <version>1.2.5</version> </dependency> <!-- alibaba的druid数据库连接池 --> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid-spring-boot-starter</artifactId> <version>1.1.9</version> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project>

项目结构：

项目结构

项目启动类：

package com.winterchen;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
@MapperScan("com.winterchen.dao") public class Springboot2MybatisDemoApplication { public static void main(String[] args) { SpringApplication.run(Springboot2MybatisDemoApplication.class, args); } }

配置：

可以根据个人使用习惯选择使用properties或者yml文件，本项目使用的是yml配置文件，所以把原本application.properties删除，创建一个application.yml文件

在resource文件夹下创建application.yml

server:
  port: 8080


spring:
    datasource:
        name: mysql_test
        type: com.alibaba.druid.pool.DruidDataSource
        #druid相关配置
        druid:
          #监控统计拦截的filters
          filters: stat
          driver-class-name: com.mysql.jdbc.Driver
          #基本属性
          url: jdbc:mysql://127.0.0.1:3306/mytest?useUnicode=true&characterEncoding=UTF-8&allowMultiQueries=true username: root password: root #配置初始化大小/最小/最大 initial-size: 1 min-idle: 1 max-active: 20 #获取连接等待超时时间 max-wait: 60000 #间隔多久进行一次检测，检测需要关闭的空闲连接 time-between-eviction-runs-millis: 60000 #一个连接在池中最小生存的时间 min-evictable-idle-time-millis: 300000 validation-query: SELECT 'x' test-while-idle: true test-on-borrow: false test-on-return: false #打开PSCache，并指定每个连接上PSCache的大小。oracle设为true，mysql设为false。分库分表较多推荐设置为false pool-prepared-statements: false max-pool-prepared-statement-per-connection-size: 20 mybatis: mapper-locations: classpath:mapper/*.xml type-aliases-package: com.winterchen.model #pagehelper pagehelper: helperDialect: mysql reasonable: true supportMethodsArguments: true params: count=countSql returnPageInfo: check

创建包：

model，dao，mapper

创建数据库和数据表

CREATE DATABASE mytest;

CREATE TABLE t_user( userId INT NOT NULL PRIMARY KEY AUTO_INCREMENT, userName VARCHAR(255) NOT NULL , password VARCHAR(255) NOT NULL , phone VARCHAR(255) NOT NULL ) ENGINE=INNODB AUTO_INCREMENT=1000 DEFAULT CHARSET=utf8;

创建实体类：`UserDomain.java`

package com.winterchen.model;

public class UserDomain { private Integer userId; private String userName; private String password; private String phone; // get,set方法略... }

创建dao：

UserDao.java

package com.winterchen.dao;



import com.winterchen.model.UserDomain;
import org.apache.ibatis.annotations.Mapper;

import java.util.List;

public interface UserDao { int insert(UserDomain record); List<UserDomain> selectUsers(); }

创建mybatis映射文件： `UserMapper.xml`

<?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.winterchen.dao.UserDao" > <sql id="BASE_TABLE"> t_user </sql> <sql id="BASE_COLUMN"> userId,userName,password,phone </sql> <insert id="insert" parameterType="com.winterchen.model.UserDomain"> INSERT INTO <include refid="BASE_TABLE"/> <trim prefix="(" suffix=")" suffixOverrides=","> userName,password, <if test="phone != null"> phone, </if> </trim> <trim prefix="VALUES(" suffix=")" suffixOverrides=","> #{userName, jdbcType=VARCHAR},#{password, jdbcType=VARCHAR}, <if test="phone != null"> #{phone, jdbcType=VARCHAR}, </if> </trim> </insert> <select id="selectUsers" resultType="com.winterchen.model.UserDomain"> SELECT <include refid="BASE_COLUMN"/> FROM <include refid="BASE_TABLE"/> </select> </mapper>

创建剩余的`controller`，`service`包和文件

UserService.java

package com.winterchen.service.user;

import com.github.pagehelper.PageInfo;
import com.winterchen.model.UserDomain;

import java.util.List;

/** * Created by Administrator on 2018/4/19. */ public interface UserService { int addUser(UserDomain user); PageInfo<UserDomain> findAllUser(int pageNum, int pageSize); }

UserServiceImpl

package com.winterchen.service.user.impl;

import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import com.winterchen.dao.UserDao;
import com.winterchen.model.UserDomain; import com.winterchen.service.user.UserService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; import java.util.List; /** * Created by Administrator on 2017/8/16. */ @Service(value = "userService") public class UserServiceImpl implements UserService { @Autowired private UserDao userDao;//这里会报错，但是并不会影响 @Override public int addUser(UserDomain user) { return userDao.insert(user); } /* * 这个方法中用到了我们开头配置依赖的分页插件pagehelper * 很简单，只需要在service层传入参数，然后将参数传递给一个插件的一个静态方法即可； * pageNum 开始页数 * pageSize 每页显示的数据条数 * */ @Override public PageInfo<UserDomain> findAllUser(int pageNum, int pageSize) { //将参数传给这个方法就可以实现物理分页了，非常简单。 PageHelper.startPage(pageNum, pageSize); List<UserDomain> userDomains = userDao.selectUsers(); PageInfo result = new PageInfo(userDomains); return result; } }

UserController.java

package com.winterchen.controller;

import com.github.pagehelper.PageHelper;
import com.winterchen.model.UserDomain;
import com.winterchen.service.user.UserService;
import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.*; /** * Created by Administrator on 2017/8/16. */ @Controller @RequestMapping(value = "/user") public class UserController { @Autowired private UserService userService; @ResponseBody @PostMapping("/add") public int addUser(UserDomain user){ return userService.addUser(user); } @ResponseBody @GetMapping("/all") public Object findAllUser( @RequestParam(name = "pageNum", required = false, defaultValue = "1") int pageNum, @RequestParam(name = "pageSize", required = false, defaultValue = "10") int pageSize){ return userService.findAllUser(pageNum,pageSize); } }

项目最终的结构

项目结构

到这里如果项目就成功搭建完成了，如果还是报错的话，请仔细看看配置，后面会给出源码地址，程序员就是要不断和bug进行斗争，加油。

测试

启动项目

这样就表示启动成功了

然后，开始测试吧，博主使用的是postMan，一个进行http请求的测试工具

添加数据

查询数据

如果需要使用多数据源的请戳这里

源码地址：

https://github.com/WinterChenS/springboot2-mybatis-demo