springboot+mybatis框架学习之环境搭建

程序员文章站 2024-03-04 11:17:41

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一、运行环境

jdk1.8；
IDEA2018；
springboot 2.3.2，改为2.0.1；

二、搭建步骤

目录结构：

springboot+mybatis框架学习之环境搭建

1.pom.xml配置文件内容

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.xiangmu01.demo</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <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>
        <!--默认版本太低，切换模板引擎版本-->
        <thymeleaf.version>3.0.9.RELEASE</thymeleaf.version>
        <thymeleaf-layout-dialect.version>2.2.2</thymeleaf-layout-dialect.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>

        <!--引入thymeleaf引擎-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <!--引入jqrery-webjar-->
        <dependency>
            <groupId>org.webjars</groupId>
            <artifactId>jquery</artifactId>
            <version>3.3.1</version>
        </dependency>
        <!--引入bootstrap-->
        <dependency>
            <groupId>org.webjars</groupId>
            <artifactId>bootstrap</artifactId>
            <version>4.0.0</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

整合mybatis时，pom.xml文件修改注意事项：

（1）添加Jackson（json解析工具）：

<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>

（2）修改springboot版本（不然会报错）

<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.3.2.RELEASE</version> 
<relativePath/> 
</parent>

（3）默认访问静态文件夹下的页面配置（配置文件中缺少这个，默认访问静态文件夹下的页面失效）

<groupId>com.xiangmu01.demo</groupId>
<artifactId>xiangmu01</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>

（3）可选内容（根据程序内代码添加）

分页插件

<dependency>
<groupId>com.github.pagehelper</groupId>
<artifactId>pagehelper-spring-boot-starter</artifactId>
<version>1.2.5</version>
</dependency>

2.application.yml内容

server:
  port: 8085

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/springbootdb?useUnicode=true&characterEncoding=UTF-8&allowMultiQueries=true
      username: root
      password:
      #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.xiangmu01.demo.model

3.UserMapper.xml配置

<?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.xiangmu01.demo.dao.UserDao" >
    <sql id="BASE_TABLE">
        user_tb
    </sql>

    <sql id="BASE_COLUMN">
        userId,userName,password,phone
    </sql>

    <insert id="insert" parameterType="com.xiangmu01.demo.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.xiangmu01.demo.model.UserDomain">
        SELECT
        <include refid="BASE_COLUMN"/>
        FROM
        <include refid="BASE_TABLE"/>
    </select>
</mapper>

三、实现代码

分层结构：

model层：（实体类）存放实体类，与数据库字段保持一致，常用于处理返回值是，当作返回值类型，保存数据库字段；
Dao层：（mapper层）封装了对某一张表的增删改查，一般写成接口，实现方法写在resource/mapper/***.xml文件中；
Service层：对一个或者多个Dao进行封装，封装成一个服务；
Controller层：负责请求转发，接收页面传输过来的参数，传给Service处理，接到返回值，再传给页面；

注意事项：

1.在启动类中:

@MapperScan("com.xiangmu01.demo.dao")//扫描指定包中的接口，非常关键，对应项目中Dao（Mapper）层的包路径；

2.继承接口的类要加上@Service注解，和@Autowired注解；例如：@Service(value = "userService")；

3.Controller层中要在最前方加入@Controller注解；

具体代码：

1.启动类

package com.xiangmu01.demo;

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

@SpringBootApplication
@MapperScan("com.xiangmu01.demo.dao")//扫描指定包中的接口
public class Xiangmu01Application {

    public static void main(String[] args) {
        SpringApplication.run(Xiangmu01Application.class, args);
    }

}

2.model类中代码

package com.xiangmu01.demo.model;

public class UserDomain {
    private Integer userId;

    private String userName;

    private String password;

    private String phone;

    public Integer getUserId() {
        return userId;
    }

    public void setUserId(Integer userId) {
        this.userId = userId;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName == null ? null : userName.trim();
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password == null ? null : password.trim();
    }

    public String getPhone() {
        return phone;
    }

    public void setPhone(String phone) {
        this.phone = phone == null ? null : phone.trim();
    }
}

3.Dao类代码

package com.xiangmu01.demo.dao;

import com.xiangmu01.demo.model.UserDomain;
import org.springframework.stereotype.Repository;

import java.util.List;

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

4.Service层代码

（1）service接口

package com.xiangmu01.demo.service.user;

import com.github.pagehelper.PageInfo;
import com.xiangmu01.demo.model.UserDomain;

/**
 * Created by Administrator on 2018/4/19.
 */
public interface UserService {

    int addUser(UserDomain user);

    PageInfo<UserDomain> findAllUser(int pageNum, int pageSize);
}

（2）imp文件下service类

package com.xiangmu01.demo.service.user.impl;


import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import com.xiangmu01.demo.dao.UserDao;
import com.xiangmu01.demo.model.UserDomain;
import com.xiangmu01.demo.service.user.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

/**
 * Created by Administrator on 2020/8/2.
 */
@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;
    }
}

5.Controller层类

package com.xiangmu01.demo.controller;



import com.xiangmu01.demo.model.UserDomain;
import com.xiangmu01.demo.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);
    }

}

springboot+mybatis框架学习之环境搭建