Spring Boot 2.x + myBatis全註解實現CRUD及自動建表

本文主要介紹一個基於Spring Boot 2.x，mySQL和myBatis完成簡單的用Web操做數據庫的demo程序，而後採用的是全註解方式實現的，徹底不須要xml配置（後續會在寫一個全xml配置demo）。主要支持如下功能：
（1） 數據庫自動建表，如本例中的user表。
（2） 數據庫CRUD(create read update delete)操做。
（3） 經過http get操做user表。

環境準備：
（1） IDEA(建議使用Ultimate版本，會自帶經過IDEA操做database的功能)
（2） MySQL
（3） Maven + JDK8

項目目錄結構：

\---main
    +---java
    |   \---hello
    |       |   MainApplication.java
    |       |   
    |       +---bean
    |       |       User.java
    |       |       
    |       +---config
    |       |       MyBatisMapperScannerConfig.java
    |       |       MybatisTableConfig.java
    |       |       
    |       +---controller
    |       |       UserController.java
    |       |       
    |       +---dao
    |       |       UserDao.java
    |       |       
    |       \---service
    |               UserService.java
    |               
    \---resources
            application.properties
            sql.txt
pom.xml

數據庫和用戶表：
默認的使用數據庫是MySQL下的sakila，這個能夠經過修改application.properties裏的配置更改本地數據庫名。
user表用的是相似下面的SQL語句建立的：

CREATE TABLE `user` (
    `id` int(13) NOT NULL AUTO_INCREMENT,
    `name` varchar(33) DEFAULT NULL,
    `age` int(3) DEFAULT NULL,
    `money` double DEFAULT NULL,
    PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8

本demo採用了自動建表的方式，即在Spring Boot啓動的時候會自動根據
（1） application.properties裏的配置
（2） config/MyBatisMapperScannerConfig.java和config/ MybatisTableConfig.java
（3） bean/user.json裏面設置的註解
經過第三方框架mybatis.actable完成表的自動建立功能。
具體內容能夠參考https://blog.csdn.net/qq_43670895/article/details/83986715

須要注意的是，使用第三方框架mybatis.actable的時候如下四個依賴項都須要引入：

<dependency>
            <groupId>com.gitee.sunchenbin.mybatis.actable</groupId>
            <artifactId>mybatis-enhance-actable</artifactId>
            <version>1.0.3</version>
        </dependency>
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>3.4</version>
        </dependency>
        <dependency>
            <groupId>net.sf.json-lib</groupId>
            <artifactId>json-lib</artifactId>
            <version>2.4</version>
            <classifier>jdk15</classifier>
            <exclusions>
                <exclusion>
                    <artifactId>commons-logging</artifactId>
                    <groupId>commons-logging</groupId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.0.18</version>
        </dependency>

pom.xml pom中須要添加boot-starter-web的依賴，MySQL鏈接的依賴，myBatis的依賴，以及第三方框架mybatis.actable須要的四個依賴。

<?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>MybatisDemo</groupId>
    <artifactId>MybatisDemo</artifactId>
    <version>1.0-SNAPSHOT</version>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.6.RELEASE</version>
    </parent>

    <properties>
        <java.version>1.8</java.version>
    </properties>

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

    <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>
        </dependency>
        <dependency>
            <groupId>com.gitee.sunchenbin.mybatis.actable</groupId>
            <artifactId>mybatis-enhance-actable</artifactId>
            <version>1.0.3</version>
        </dependency>
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>3.4</version>
        </dependency>
        <dependency>
            <groupId>net.sf.json-lib</groupId>
            <artifactId>json-lib</artifactId>
            <version>2.4</version>
            <classifier>jdk15</classifier>
            <exclusions>
                <exclusion>
                    <artifactId>commons-logging</artifactId>
                    <groupId>commons-logging</groupId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.0.18</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>
</project>

配置 application.properties，鏈接本地MySQL數據庫以及自動建表配置

server.port=8333
# 數據庫爲sakila
spring.datasource.url=jdbc:mysql://127.0.0.1:3306/sakila?useUnicode=true&characterEncoding=utf8&useSSL=false&serverTimezone=GMT%2B8&allowPublicKeyRetrieval=true
spring.datasource.username=root
spring.datasource.password=123456
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

# 自動建表的配置，結合hello.config能夠自動建立user的表
mybatis.table.auto=create
mybatis.model.pack=hello.bean
mybatis.database.type=mysql

MyBatisMapperScannerConfig.java 自動建表配置類

package hello.config;

import org.mybatis.spring.mapper.MapperScannerConfigurer;
import org.springframework.boot.autoconfigure.AutoConfigureAfter;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;


@Configuration
@AutoConfigureAfter(MybatisTableConfig.class)
public class MyBatisMapperScannerConfig {

    @Bean
    public MapperScannerConfigurer mapperScannerConfigurer() throws Exception{
        MapperScannerConfigurer mapperScannerConfigurer = new MapperScannerConfigurer();
        mapperScannerConfigurer.setBasePackage("com.example.mapper.*;com.gitee.sunchenbin.mybatis.actable.dao.*");
        mapperScannerConfigurer.setSqlSessionFactoryBeanName("sqlSessionFactory");
        return mapperScannerConfigurer;
    }

}

MybatisTableConfig.java 自動建表配置類，須要配置自動建表的User類路徑hello.bean.*

package hello.config;

import com.alibaba.druid.pool.DruidDataSource;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.beans.factory.config.PropertiesFactoryBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;

@Configuration
@ComponentScan(basePackages = {"com.gitee.sunchenbin.mybatis.actable.manager.*"})
public class MybatisTableConfig {

    @Value("${spring.datasource.driver-class-name}")
    private String driver;

    @Value("${spring.datasource.url}")
    private String url;

    @Value("${spring.datasource.username}")
    private String username;

    @Value("${spring.datasource.password}")
    private String password;

    @Bean
    public PropertiesFactoryBean configProperties() throws Exception{
        PropertiesFactoryBean propertiesFactoryBean = new PropertiesFactoryBean();
        PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
        propertiesFactoryBean.setLocations(resolver.getResources("classpath*:application.properties"));
        return propertiesFactoryBean;
    }

    @Bean
    public DruidDataSource dataSource() {
        DruidDataSource dataSource = new DruidDataSource();
        dataSource.setDriverClassName(driver);
        dataSource.setUrl(url);
        dataSource.setUsername(username);
        dataSource.setPassword(password);
        dataSource.setMaxActive(30);
        dataSource.setInitialSize(10);
        dataSource.setValidationQuery("SELECT 1");
        dataSource.setTestOnBorrow(true);
        return dataSource;
    }

    @Bean
    public DataSourceTransactionManager dataSourceTransactionManager() {
        DataSourceTransactionManager dataSourceTransactionManager = new DataSourceTransactionManager();
        dataSourceTransactionManager.setDataSource(dataSource());
        return dataSourceTransactionManager;
    }

    @Bean
    public SqlSessionFactoryBean sqlSessionFactory() throws Exception{
        SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
        sqlSessionFactoryBean.setDataSource(dataSource());
        PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
        sqlSessionFactoryBean.setMapperLocations(resolver.getResources("classpath*:com/gitee/sunchenbin/mybatis/actable/mapping/*/*.xml"));
        sqlSessionFactoryBean.setTypeAliasesPackage("hello.bean.*");
        return sqlSessionFactoryBean;
    }

}

User.java
用戶類User，基於全註解方式以實現自動建表

package hello.bean;

import com.gitee.sunchenbin.mybatis.actable.annotation.Column;
import com.gitee.sunchenbin.mybatis.actable.annotation.Table;
import com.gitee.sunchenbin.mybatis.actable.command.BaseModel;
import com.gitee.sunchenbin.mybatis.actable.constants.MySqlTypeConstant;

@Table(name = "user")
public class User extends BaseModel {
    private static final long serialVersionUID = 5199200306752426433L;

    @Column(name = "id", type = MySqlTypeConstant.INT, isAutoIncrement = true, length = 13, isKey = true)
    private int id;

    @Column(name = "name", type = MySqlTypeConstant.VARCHAR , length = 33, isNull = false)
    private String name;

    @Column(name = "age", type = MySqlTypeConstant.INT, length = 3, isNull = false)
    private int age;

    @Column(name = "money", type = MySqlTypeConstant.DOUBLE, isNull = false)
    private double money;

    public int getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public double getMoney() {
        return money;
    }

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

UserDao.java
Dao 層開發基於全註解實現數據庫CRUD操做

package hello.dao;

import hello.bean.User;
import org.apache.ibatis.annotations.*;

import java.util.List;

/**
 * 基於註解實現數據庫 CRUD(create read update delete)
 */
@Mapper
public interface UserDao {

    /**
     * 插入用戶信息
     */
    @Insert("INSERT INTO user(name, age, money) VALUES(#{name}, #{age}, #{money})")
    void insertUser(@Param("name") String name, @Param("age") Integer age, @Param("money") Double money);

    /**
     * 經過名字查詢用戶信息
     */
    @Select("SELECT * FROM user WHERE name = #{name}")
    List<User> findUserByName(@Param("name") String name);

    /**
     * 查詢全部用戶信息
     */
    @Select("SELECT * FROM user")
    List<User> findAllUser();

    /**
     * 根據 id 更新用戶信息
     */
    @Update("UPDATE user SET name = #{name},age = #{age},money= #{money} WHERE id = #{id}")
    void updateUser(@Param("name") String name, @Param("age") Integer age, @Param("money") Double money,
                    @Param("id") int id);

    /**
     * 根據 id 刪除用戶信息
     */
    @Delete("DELETE from user WHERE name = #{name}")
    void deleteUser(@Param("name") String name);

    /**
     * 刪除user表裏面的全部數據
     */
    @Delete("DELETE from user WHERE 1 = 1")
    void deleteAllUserData();
}

UserController.java
Controller層實現http get的insert，query，update，delete，clear等操做。

package hello.controller;

import hello.bean.User;
import hello.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;


/**
 * 實現 CRUD http 請求對應controller接口
 */
@RestController
@RequestMapping("/user")
public class UserController {
    @Autowired
    private UserService userService;

    // http://localhost:8333/user/insert?name=ace&age=18&money=0
    @GetMapping("/insert")
    public List<User> insert(@RequestParam(value = "name", required = true) String name,
                             @RequestParam(value = "age", required = true) int age,
                             @RequestParam(value = "money", required = true) double money) {
        userService.insertOneService(name, age, money);
        return userService.selectAllUser();
    }

    // http://localhost:8333/user/query?name=ace
    @GetMapping("/query")
    public List<User> queryByName(@RequestParam(value = "name", required = false) String name) {
        if (name == null) {
            return userService.selectAllUser();
        }
        return userService.selectUserByName(name);
    }

    @GetMapping("/update")
    public List<User> update(@RequestParam(value = "name", required = true) String name,
                             @RequestParam(value = "age", required = true) int age,
                             @RequestParam(value = "money", required = true) double money) {
        userService.updateService(name, age, money);
        return userService.selectUserByName(name);
    }

    @GetMapping("/delete")
    public String delete(@RequestParam(value = "name", required = true) String name) {
        userService.deleteService(name);
        return "OK";
    }

    @GetMapping("/clear")
    public List<User> testClear() {
        userService.clearService();
        return userService.selectAllUser();
    }

    @GetMapping("/changemoney")
    public List<User> testchangemoney() {
        userService.insertService();
        userService.changemoney();
        return userService.selectAllUser();
    }

}

UserService.java
Service層

package hello.service;

import hello.bean.User;
import hello.dao.UserDao;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.util.List;
import java.util.stream.Collectors;

@Service
public class UserService {
    @Autowired
    private UserDao userDao;


    /**
     * 根據名字查找用戶
     */
    public List<User> selectUserByName(String name) {
        return userDao.findUserByName(name);
    }

    /**
     * 查找全部用戶
     */
    public List<User> selectAllUser() {
        return userDao.findAllUser();
    }

    /**
     * 插入兩個用戶
     */
    public void insertService() {
        userDao.insertUser("Ace", 22, 3000.0);
        userDao.insertUser("Blink", 19, 3000.0);
    }

    /**
     * 插入某個指定用戶
     */
    public void insertOneService(String name, int age, double money) {
        userDao.insertUser(name, age, money);
    }

    /**
     * 經過名字更新用戶信息
     */
    @Transactional
    public void updateService(String name, int age, double money) {
        List<User> users = userDao.findUserByName(name);
        if (users.isEmpty()) {
            return;
        }
        List<Integer> ids = users.stream().map(User::getId).collect(Collectors.toList());
        ids.forEach(id -> userDao.updateUser(name, age, money, id));
    }

    /**
     * 根據id 刪除用戶
     */
    public void deleteService(String name) {
        userDao.deleteUser(name);
    }

    /**
     * 清除表內全部數據
     */
    public void clearService() {
        userDao.deleteAllUserData();
    }

    /**
     * 模擬事務。因爲加上了 @Transactional註解，若是轉帳中途出了意外 Ace 和 Blink 的錢都不會改變。
     */
    @Transactional
    public void changemoney() {
        userDao.updateUser("Ace", 22, 2000.0, 3);
        // 模擬轉帳過程當中可能遇到的意外情況
        int temp = 1 / 0;
        userDao.updateUser("Blink", 19, 4000.0, 4);
    }
}

MainApplication.java
Spring Boot啓動類，經過繼承CommandLineRunner在Spring Boot啓動的時候，在表自動建立完後會在表中插入一些數據。

package hello;

import hello.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

/**
 * 這份demo須要本地安裝mySQL,並會在Spring Boot啓動的時候自動在sakila數據庫下按照sql.txt裏面的語句新建一個user的表
 */
@SpringBootApplication
public class MainApplication implements CommandLineRunner {

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

    @Autowired
    UserService userService;

    @Override
    public void run(String... args) throws Exception {
        userService.insertService();
    }
}

功能演示：
（1）數據庫表自動建立，能夠經過console看到user表的建立

（2）查詢query

（3）insert插入數據

（4）update更新數據

（5）delete刪除數據

截止目前，一個基於Spring Boot 2.x，mySQL和myBatis完成簡單的用Web操做數據庫的全註解實現demo程序就已經完成啦~