Spring Boot整合MyBatis及generater自动生成DAO并实现RESTful API

1.在项目的POM.XML文件的build标签中，增加如下内容：

<plugin>
                <groupId>org.mybatis.generator</groupId>
                <artifactId>mybatis-generator-maven-plugin</artifactId>
                <version>1.4.0</version>
                <dependencies>
                    <dependency>
                        <groupId> mysql</groupId>
                        <artifactId> mysql-connector-java</artifactId>
                        <version> 8.0.27</version>
                    </dependency>
                    <dependency>
                        <groupId>org.mybatis.generator</groupId>
                        <artifactId>mybatis-generator-core</artifactId>
                        <version>1.4.0</version>
                    </dependency>
                </dependencies>
                <executions>
                    <execution>
                        <id>Generate MyBatis Artifacts</id>
                        <phase>package</phase>
                        <goals>
                            <goal>generate</goal>
                        </goals>
                    </execution>
                </executions>
                <configuration>
                    <!--允许移动生成的文件 -->
                    <verbose>true</verbose>
                    <!-- 是否覆盖 -->
                    <overwrite>true</overwrite>
                    <!-- 自动生成的配置 -->
                    <configurationFile>
                        src/main/resources/mybatis-generator.xml</configurationFile>
                </configuration>
            </plugin>

2.将application.properties 改为application.yml

server:
  port: 8080
  servlet:
    context-path: /

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/mytest?useUnicode=true&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTC
    username: root
    password: root

mybatis:
  mapper-locations: classpath:mapping/*.xml
  type-aliases-package: cn.felixfang.flog.entity

 

3.从以上文件我们可以看到，对应的configurationFile的位置，所以接下来，我们将在resources中建立mybatis-generator.xml
mybatis-generator.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE generatorConfiguration
        PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
        "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">
<generatorConfiguration>

    <context id="DB2Tables" targetRuntime="MyBatis3">
        <commentGenerator>
            <property name="suppressDate" value="true"/>
            <property name="suppressAllComments" value="true"/>
        </commentGenerator>
        <!--数据库链接地址账号密码-->
        <jdbcConnection driverClass="com.mysql.jdbc.Driver" connectionURL="jdbc:mysql://127.0.0.1:3306/mytest?nullCatalogMeansCurrent=true" userId="root" password="root888">
        </jdbcConnection>
        <javaTypeResolver>
            <property name="forceBigDecimals" value="false"/>
        </javaTypeResolver>
        <!--生成Model类存放位置-->
        <javaModelGenerator targetPackage="cn.na.demo.model" targetProject="src/main/java">
            <property name="enableSubPackages" value="false"/>
            <property name="trimStrings" value="true"/>
        </javaModelGenerator>
        <!--生成映射文件存放位置xml-->
        <!-- 生成SQL map的XML文件生成器，
        注意，在Mybatis3之后，我们可以使用mapper.xml文件+Mapper接口（或者不用mapper接口），
            或者只使用Mapper接口+Annotation，所以，如果 javaClientGenerator配置中配置了需要生成XML的话，这个元素就必须配置
        targetPackage/targetProject:同javaModelGenerator
     -->
        <sqlMapGenerator targetPackage="cn.na.demo.mapper" targetProject="src/main/java">
            <property name="enableSubPackages" value="false"/>
        </sqlMapGenerator>
        <!--生成Dao类存放位置-->
        <!-- 对于mybatis来说，即生成Mapper接口，注意，如果没有配置该元素，那么默认不会生成Mapper接口
        targetPackage/targetProject:同javaModelGenerator
        type：选择怎么生成mapper接口（在MyBatis3/MyBatis3Simple下）：
            1，ANNOTATEDMAPPER：会生成使用Mapper接口+Annotation的方式创建（SQL生成在annotation中），不会生成对应的XML；
            2，MIXEDMAPPER：使用混合配置，会生成Mapper接口，并适当添加合适的Annotation，但是XML会生成在XML中；
            3，XMLMAPPER：会生成Mapper接口，接口完全依赖XML；
        注意，如果context是MyBatis3Simple：只支持ANNOTATEDMAPPER和XMLMAPPER
    -->
        <javaClientGenerator type="ANNOTATEDMAPPER" targetPackage="cn.na.demo.dao" targetProject="src/main/java">
            <property name="enableSubPackages" value="false"/>
        </javaClientGenerator>
        <!--生成对应表及类名-->
        <table tableName="book" domainObjectName="book" schema= "mytest" enableCountByExample="false" enableUpdateByExample="false" enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false"></table>
    </context>
</generatorConfiguration>

然后使用命令：mvn mybatis-generator:generate，即可以生成相应的文件。

4.修改Mapper

在bookMapper.java中，增加以下内容：

@Select({
        "select",
        "bookid, bookname, sl, price",
        "from book"
    })
    @Results({
        @Result(column="bookid", property="bookid", jdbcType=JdbcType.INTEGER, id=true),
        @Result(column="bookname", property="bookname", jdbcType=JdbcType.VARCHAR),
        @Result(column="sl", property="sl", jdbcType=JdbcType.INTEGER),
        @Result(column="price", property="price", jdbcType=JdbcType.DECIMAL)
    })
    List<book> selectAll();

5.添加Service

然后我们在service文件夹中，添加一个bookservice.java接口，同时再添加一个impl文件夹，表示它的实现，在impl文件夹中增加bookserviceimpl.java类，实现bookservice接口。
bookservice.java

package cn.fh.backapi.service;

import java.util.List;

import cn.fh.demo.model.book;

public interface bookservice {
    public void insert(book book);

    public book selectByPrimaryKey(Integer id);

    public List<book> selectAll();
}

bookserviceimpl.java

package cn.fh.backapi.service.impl;

import java.util.List;

import javax.annotation.Resource;

import org.springframework.context.annotation.ComponentScan;
import org.springframework.stereotype.Service;

import cn.fh.backapi.service.bookservice;
import cn.fh.demo.dao.bookMapper;
import cn.fh.demo.model.book;

@ComponentScan({"cn.fh.demo.dao"})
@Service("bookservice")

public class bookserviceimpl implements bookservice {
    @Resource
    private bookMapper bookMapper;

    @Override
    public void insert(book book) {
        bookMapper.insert(book);
    }


    public book selectByPrimaryKey(Integer id) {
        return bookMapper.selectByPrimaryKey(id);
    }


    public List<book> selectAll() {
        return bookMapper.selectAll();
    }

}

6. 添加controller

接下来，我们添加controller文件夹，并实现bookcontroller.java控制器。

bookcontroller.java

import java.util.List;

import javax.annotation.Resource;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import cn.na.cwbb.model.book;
import cn.na.cwbb.service.bookservice;

@RestController
@ComponentScan({ "cn.na.cwbb.service" })
@MapperScan("cn.na.cwbb.dao")
public class bookcontroller {
    @Resource
    private bookservice booksService;

    @RequestMapping(value = "/books", method = RequestMethod.GET)
    public List<book> getAllBooks() {
        List<book> bookList = booksService.selectAll();
        return bookList;
    }

    @RequestMapping(value = "/{id}", method = RequestMethod.GET)
    public book getbook(@PathVariable("id") Integer id) {

        book book = booksService.selectByPrimaryKey(id);
        return book;
    }
}

其中 @PathVariable是spring3.0的一个新功能：接收请求路径中占位符的值

 

7. 含参数访问

给个简单的实例：

@CrossOrigin
    @RequestMapping(value="/getBookById", method = RequestMethod.POST)
    @ResponseBody
    public String getBookById(@RequestBody String id){
        Books books =  booksService.selectByPrimaryKey(Integer.parseInt(id));
        return "HelloWord"+"fasdf--"+books.getName()+"--"+books.getAuthor();
    }

登录usermapper多参数查询

@Select({
            "select",
            "username, password",
            "from user",
            "where username = #{username,jdbcType=VARCHAR} and password = #{password,jdbcType=VARCHAR}"
    })
    @Results({
            @Result(column = "username", property = "username", jdbcType = JdbcType.VARCHAR),
            @Result(column = "password", property = "password", jdbcType = JdbcType.VARCHAR)
    })
    user getuser(String username,String password);