二、springboot中mybatis項目入門——註解版

一、Maven依賴

 <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <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>2.1.0</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>

二、Druid依賴

<!-- https://mvnrepository.com/artifact/com.alibaba/druid -->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid</artifactId>
    <version>1.1.20</version>
</dependency>

三、yml配置

spring:
  datasource:
    username: root
    password: root
    #mysql8版本以上的驅動包，需要指定以下時區
    url: jdbc:mysql://127.0.0.1:3306/mybatis?serverTimezone=GMT%2B8
    #mysql8版本以上指定新的驅動類
    driver-class-name: com.mysql.cj.jdbc.Driver
    #引入Druid數據源
    type: com.alibaba.druid.pool.DruidDataSource

    #   數據源其他配置, DataSourceProperties中沒有相關屬性,默認無法綁定
    initialSize: 8
    minIdle: 5
    maxActive: 20
    maxWait: 60000
    timeBetweenEvictionRunsMillis: 60000
    minEvictableIdleTimeMillis: 300000
    validationQuery: SELECT 1 FROM DUAL
    testWhileIdle: true
    testOnBorrow: false
    testOnReturn: false
    poolPreparedStatements: true
    #   配置監控統計攔截的filters，去掉後監控界面sql無法統計，'wall'用於防火牆
    filters: stat,wall,logback
    maxPoolPreparedStatementPerConnectionSize: 25
    useGlobalDataSourceStat: true
    connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500

四、創建config文件

package com.example.springbootmybatis.config;

import com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.druid.support.http.StatViewServlet;
import com.alibaba.druid.support.http.WebStatFilter;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import javax.servlet.Filter;
import javax.sql.DataSource;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;

/**
 * 綁定Druid相關信息
 * @Auther: xrzhang
 */
@Configuration
public class DruidConfig {


    @ConfigurationProperties(prefix = "spring.datasource")
    @Bean
    public DataSource druid() {
        return new DruidDataSource();
    }

    /**
     * 配置一個druid的監控
     * 1. 配置一個druid的後臺 管理servlet
     * 2. 配置一個druid的filter
     *
     */
    // 1. 配置一個druid的後臺管理servlet
    @Bean
    public ServletRegistrationBean statViewServlet() {
        //注意：請求是 /druid/*
        ServletRegistrationBean<StatViewServlet> bean = new ServletRegistrationBean<>(new StatViewServlet(), "/druid/*");

        //設置初始化參數值
        Map<String, String> initParam = new HashMap<>();

        initParam.put(StatViewServlet.PARAM_NAME_USERNAME, "root");
        initParam.put(StatViewServlet.PARAM_NAME_PASSWORD, "123");
        //如果不寫，則默認所有ip都可以訪問
        initParam.put(StatViewServlet.PARAM_NAME_ALLOW, "");
        initParam.put(StatViewServlet.PARAM_NAME_DENY, "192.168.10.1");

        bean.setInitParameters(initParam);

        return bean;
    }

    //2. 配置一個druid的filter
    @Bean
    public FilterRegistrationBean webStatFilter() {
        FilterRegistrationBean<Filter> bean = new FilterRegistrationBean<>();
        bean.setFilter(new WebStatFilter());

        Map<String, String> initPrams = new HashMap<>();
        initPrams.put(WebStatFilter.PARAM_NAME_EXCLUSIONS, "*.js,*.css,/druid/*");
        bean.setInitParameters(initPrams);

        //設置攔截請求
        bean.setUrlPatterns(Arrays.asList("/*"));
        return bean;
    }

}

四、訪問：http://localhost:8080/druid/，出現，說明配置成功

 五、創建三個實體

1、Bill

package com.example.springbootmybatis.entities;

import java.util.Date;

/**
 * 帳單實體類
 * @Title: Provider
 * @Description: com.mengxuegu.springboot.entities
 * @Auther: www.mengxuegu.com
 * @Version: 1.0
 */
public class Bill {

    private Integer bid;
    // 賬單編碼
    private String billCode;
    // 商品名稱
    private String billName;
    // 商品單位
    private String billCom;
    // 商品數量
    private Integer billNum;
    // 總金額
    private Double money;
    // 供應商
    private Provider provider;
    // 是否付款 0 未付款， 1已付款
    private Integer pay;
    // 創建時間
    private Date createDate;
    public Bill() {}

    public Bill(Integer bid, String billCode, String billName, String billCom, Integer billNum, Double money, Provider provider, Integer pay) {
        this.bid = bid;
        this.billCode = billCode;
        this.billName = billName;
        this.billCom = billCom;
        this.billNum = billNum;
        this.money = money;
        this.provider = provider;
        this.pay = pay;
        this.createDate = new Date();
    }

    @Override
    public String toString() {
        return "Bill{" +
                "bid=" + bid +
                ", billCode='" + billCode + '\'' +
                ", billName='" + billName + '\'' +
                ", billCom='" + billCom + '\'' +
                ", billNum=" + billNum +
                ", money=" + money +
                ", provider=" + provider +
                ", pay=" + pay +
                ", createDate=" + createDate +
                '}';
    }

    public Integer getBid() {
        return bid;
    }

    public void setBid(Integer bid) {
        this.bid = bid;
    }

    public String getBillCode() {
        return billCode;
    }

    public void setBillCode(String billCode) {
        this.billCode = billCode;
    }

    public String getBillName() {
        return billName;
    }

    public void setBillName(String billName) {
        this.billName = billName;
    }

    public String getBillCom() {
        return billCom;
    }

    public void setBillCom(String billCom) {
        this.billCom = billCom;
    }

    public Integer getBillNum() {
        return billNum;
    }

    public void setBillNum(Integer billNum) {
        this.billNum = billNum;
    }

    public Double getMoney() {
        return money;
    }

    public void setMoney(Double money) {
        this.money = money;
    }

    public Provider getProvider() {
        return provider;
    }

    public void setProvider(Provider provider) {
        this.provider = provider;
    }

    public Integer getPay() {
        return pay;
    }

    public void setPay(Integer pay) {
        this.pay = pay;
    }

    public Date getCreateDate() {
        return createDate;
    }

    public void setCreateDate(Date createDate) {
        this.createDate = createDate;
    }
}

2、provider

package com.example.springbootmybatis.entities;

import java.util.Date;

/**
 * 供應商實體類
 * @Title: Provider
 * @Description: com.mengxuegu.springboot.entities
 * @Auther: www.mengxuegu.com
 * @Version: 1.0
 */

public class Provider {
    private Integer pid;
    //供應商編碼
    private String providerCode;
    //供應商名稱
    private String providerName;
    //聯繫人
    private String people;
    //聯繫電話
    private String phone;
    //聯繫地址
    private String address;
    //傳真
    private String fax;
    //描述
    private String describe;
    // 創建時間
    private Date createDate;

    public Provider() {
    }

    public Provider(Integer pid, String providerCode, String providerName, String people, String phone, String address, String fax, String describe) {
        this.pid = pid;
        this.providerCode = providerCode;
        this.providerName = providerName;
        this.people = people;
        this.phone = phone;
        this.address = address;
        this.fax = fax;
        this.describe = describe;
        this.createDate = new Date();
    }

    @Override
    public String toString() {
        return "Provider{" +
                "pid=" + pid +
                ", providerCode='" + providerCode + '\'' +
                ", providerName='" + providerName + '\'' +
                ", people='" + people + '\'' +
                ", phone='" + phone + '\'' +
                ", address='" + address + '\'' +
                ", fax='" + fax + '\'' +
                ", describe='" + describe + '\'' +
                ", createDate=" + createDate +
                '}';
    }

    public Integer getPid() {
        return pid;
    }

    public void setPid(Integer pid) {
        this.pid = pid;
    }

    public String getProviderCode() {
        return providerCode;
    }

    public void setProviderCode(String providerCode) {
        this.providerCode = providerCode;
    }

    public String getProviderName() {
        return providerName;
    }

    public void setProviderName(String providerName) {
        this.providerName = providerName;
    }

    public String getPeople() {
        return people;
    }

    public void setPeople(String people) {
        this.people = people;
    }

    public String getPhone() {
        return phone;
    }

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

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public String getFax() {
        return fax;
    }

    public void setFax(String fax) {
        this.fax = fax;
    }

    public String getDescribe() {
        return describe;
    }

    public void setDescribe(String describe) {
        this.describe = describe;
    }

    public Date getCreateDate() {
        return createDate;
    }

    public void setCreateDate(Date date) {
        this.createDate = date;
    }
}

3、User

package com.example.springbootmybatis.entities;

import java.util.Date;

/**
 * 用戶實體類
 * @Title: Provider
 * @Description: com.mengxuegu.springboot.entities
 * @Auther: www.mengxuegu.com
 * @Version: 1.0
 */
public class User {

    private Integer id;
    //用戶名
	private String username;
    //真實姓名
    private String realName;
    //用戶密碼
    private String password;
    //性別：1 女  2 男
    private Integer gender;
    //生日
    private Date birthday;
    //1管理員  2經理  3普通用戶
    private Integer userType;

    public User() {
    }

    public User(String username, Integer gender) {
        this.username = username;
        this.gender = gender;
    }

    public Integer getId() {
        return id;
    }

    public User(Integer id, String username, String realName, String password, Integer gender, Integer userType) {
        this.id = id;
        this.username = username;
        this.realName = realName;
        this.password = password;
        this.gender = gender;
        this.birthday = new Date();
        this.userType = userType;
    }

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

    public String getUsername() {
        return username;
    }

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

    public String getRealName() {
        return realName;
    }

    public void setRealName(String realName) {
        this.realName = realName;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public Integer getGender() {
        return gender;
    }

    public void setGender(Integer gender) {
        this.gender = gender;
    }

    public Date getBirthday() {
        return birthday;
    }

    public void setBirthday(Date birthday) {
        this.birthday = birthday;
    }

    public Integer getUserType() {
        return userType;
    }

    public void setUserType(Integer userType) {
        this.userType = userType;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", username='" + username + '\'' +
                ", realName='" + realName + '\'' +
                ", password='" + password + '\'' +
                ", gender=" + gender +
                ", birthday=" + birthday +
                ", userType=" + userType +
                '}';
    }
}

六、創建映射接口

package com.example.springbootmybatis.mapper;

import com.example.springbootmybatis.entities.Provider;
import org.apache.ibatis.annotations.*;

@Mapper
public interface ProviderMapper {
    @Select("select * from provider where pid=#{proId}")
    Provider getProviderById(Integer proId);//注意，#{裏面的東西是這裏的參數名}

    @Options(useGeneratedKeys = true, keyProperty = "pid")
    //指定哪一個實體類中的屬性封裝主鍵值
    @Insert("insert into provider(providerName) values (#{providerName})")
    int addProvider(Provider provider);
    @Delete("delete from provider where pid=#{pid}")
    int deleteProviderByPid(Integer pid);
    @Update("update provider set providerName=#{providerName} where pid=#{pid}")
    int updateProvider(Provider provider);

}

七、寫控制層

package com.example.springbootmybatis.controller;

import com.example.springbootmybatis.entities.Provider;
import com.example.springbootmybatis.mapper.ProviderMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class ProviderController {
    @Autowired
    ProviderMapper providerMapper;
    @GetMapping("/provider/{pid}")
    public Provider getProvider(@PathVariable("pid")Integer pid){
        Provider provider = providerMapper.getProviderById(pid);
        return provider;
    }
    @GetMapping("/provider")
    public Provider addProvider(Provider provider){
        providerMapper.addProvider(provider);
        return provider;
    }
}

八、關於屬於庫屬性名與實體屬性名不一樣的問題

比如：數據庫屬性名有一個"provider_code"，實體類中則定義的是駱駝命名法“providerCode” 

 

package com.example.springbootmybatis.config;

import org.mybatis.spring.boot.autoconfigure.ConfigurationCustomizer;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class MyBatisConfig {
    @Bean
    public ConfigurationCustomizer configurationCustomizer(){
        ConfigurationCustomizer conf = new ConfigurationCustomizer(){
            @Override
            public void customize(org.apache.ibatis.session.Configuration configuration) {
                configuration.setMapUnderscoreToCamelCase(true);
            }
        };
        return conf;
    }
}

最後，整體的文件夾是這樣的：

 

 九、相關改進

可以將mapper文件夾下的ProviderMapper文件的@Mapper去掉，在main()函數上註解MapperScan("com.example.springbootmybatis.mapper")，這樣就可以不用每個mapper文件都加@Mapper註解了。