mybatis plus实战：springboot 结合mybatis plus实例

拼搏现实的明天。 2022-12-03 08:52 169阅读 0赞

### 文章目录 ###

*  前言
 *  集成步骤：
 *  源码地址：

# 前言 #

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3BlbmdnZXJoZQ_size_16_color_FFFFFF_t_70_pic_center]

mybatis plus 不但能够像HIbernate一样针对对象操作数据库，也支持mybatis写原生的sql。而且可以根据表自动生成dao,service,controler层的增删改成方法，极大提升开发效率。

# 集成步骤： #

1.  pom.xml 引入jar包：

<dependency>
                <groupId>com.baomidou</groupId>
                <artifactId>mybatisplus-spring-boot-starter</artifactId>
                <version>${mybatisplus.boot.version}</version>
            </dependency>
            <dependency>
                <groupId>com.baomidou</groupId>
                <artifactId>mybatis-plus</artifactId>
                <version>${mybatisplus.version}</version>
            </dependency>

1.  application.yml 配置mybatis plus信息：

mybatis-plus:
      mapper-locations: classpath:com/*/mapper/*.xml
      #实体扫描，多个package用逗号或者分号分隔
      typeAliasesPackage: com.common.model
      global-config:
        #主键类型  0:"数据库ID自增", 1:"用户输入ID",2:"全局唯一ID (数字类型唯一ID)", 3:"全局唯一ID UUID";
        id-type: 0
        #字段策略 0:"忽略判断",1:"非 NULL 判断"),2:"非空判断"
        field-strategy: 2
        #驼峰下划线转换
        db-column-underline: true
        #刷新mapper 调试神器
        refresh-mapper: true
        #数据库大写下划线转换
        #capital-mode: true
        #逻辑删除配置（下面3个配置）
        logic-delete-value: 1
        logic-not-delete-value: 0
        sql-injector: com.baomidou.mybatisplus.mapper.LogicSqlInjector
      configuration:
        #配置返回数据库(column下划线命名&&返回java实体是驼峰命名)，自动匹配无需as（没开启这个，SQL需要写as： select user_id as userId）
        map-underscore-to-camel-case: true
        cache-enabled: false
        #配置JdbcTypeForNull, oracle数据库必须配置
        jdbc-type-for-null: 'null'

1.  Mapper.xml 编写：

<?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.enjoypark.dao.StudentDao">
    
       
       <resultMap id="BaseResultMap" type="com.enjoypark.model.Student">
          <id column="id" property="id" />
          <result column="name" property="name" />
          <result column="sex" property="sex" />
          <result column="password" property="password" />
          <result column="create_time" property="createTime" />
       </resultMap>
    
        
        <sql id="Base_Column_List">
            id, name, sex, password, create_time
        </sql>
    
    	<select id="selectListPage" resultMap="BaseResultMap">
    	    SELECT <include refid="Base_Column_List" />
    	    from student t
    		where 1=1
    		<if test="student!=null and student.id!=null">
    			and t.id=#{student.id}
    		</if>
    		<if test="student!=null and student.name!=null">
    			and t.name=#{student.name}
    		</if>
    		<if test="student!=null and student.sex!=null">
    			and t.sex=#{student.sex}
    		</if>
    		<if test="student!=null and student.password!=null">
    			and t.password=#{student.password}
    		</if>
    		<if test="student!=null and student.createTime!=null">
    			and t.create_time=#{student.createTime}
    		</if>
    	</select>
    </mapper>

1.  dao层编写：

package com.enjoypark.dao;
    
    import com.baomidou.mybatisplus.mapper.BaseMapper;
    import com.baomidou.mybatisplus.plugins.Page;
    import com.enjoypark.model.Student;
    import org.apache.ibatis.annotations.Param;
    import org.springframework.stereotype.Repository;
    
    import java.util.List;
    import java.util.Map;
    
    /** * <p> * Dao 接口 * </p> * * @author wangPeng * @since 2019-08-28 */
    @Repository()
    public interface StudentDao extends BaseMapper<Student> { 
    
    	  /** * mybatis-plus 和mybatis结合分页查询 * @return */
    	  public List<Student> selectListPage(Page<Map> mapPage, @Param("student") Student student);
    }

1.  编写service层接口：

package com.enjoypark.service;
    
    import com.enjoypark.model.Student;
    import com.baomidou.mybatisplus.service.IService;
    
    import java.util.List;
    import java.io.Serializable;
    
    /** * <p> * 服务类 * </p> * * @author wangPeng * @since 2019-08-28 */
    public interface StudentService extends IService<Student> { 
    
        /** * 分页查询 * mybatis-plus 和mybatis结合分页查询 * @param userQu * @param firstStart * @param pageSize * @return */
        public List<Student> getBypage(Student studentQu, int firstStart, int pagesize);
    
        /** * 查询表记录总数 */
        public Long getAllCount(Student studentQu);
    
         /** * 根据实体保存 */
        public int saveStudent(Student student);
    
        /** * 根据id查询实体 */
        public Student getByID(Serializable studentID);
    
         /** * 根据实体Id更新 */
        public int updateStudent(Student student);
    
        /** * 根据Id删除 */
        public int deleteByID(Serializable studentID);
    }

1.  编写service impl实现类：

package com.enjoypark.service.impl;
    
    import java.io.Serializable;
    import java.util.List;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Service;
    
    import com.baomidou.mybatisplus.mapper.EntityWrapper;
    import com.baomidou.mybatisplus.plugins.Page;
    
    import com.enjoypark.model.Student;
    import com.enjoypark.dao.StudentDao;
    import com.enjoypark.service.StudentService;
    import com.baomidou.mybatisplus.service.impl.ServiceImpl;
    /** * <p> * 服务实现类 * </p> * * @author wangPeng * @since 2019-08-28 */
    @Service
    public class StudentServiceImpl extends ServiceImpl<StudentDao, Student> implements StudentService { 
    
    
        @Autowired
        private StudentDao studentDao;
    
    	/** * 分页查询 * mybatis-plus 和mybatis结合分页查询 * @param userQu * @param firstStart * @param pageSize * @return */
    	@Override
        public List<Student> getBypage(Student studentQu, int firstStart, int pagesize)
        { 
            return studentDao.selectListPage(new Page<>(firstStart,pagesize),studentQu);
        }
    
        /** * 查询表记录总数 */
        @Override
        public Long getAllCount(Student studentQu){ 
            return studentDao.selectCount(new EntityWrapper<Student>()).longValue();
        }
    
         /** * 根据实体保存 */
        @Override
        public int saveStudent(Student student){ 
        	return studentDao.insert(student);
        }
    
        /** * 根据id查询实体 */
        @Override
        public Student getByID(Serializable studentID) { 
        	return studentDao.selectById(studentID);
        }
    
         /** * 根据实体Id更新(updateById只更新有值得字段，updateAllColumById所有字段都更新) */
        @Override
        public int updateStudent(Student student){ 
        	return studentDao.updateById(student);
        }
    
        /** * 根据Id删除 */
        @Override
        public int deleteByID(Serializable studentID){ 
           return studentDao.deleteById(studentID);
        }
    }

1.  编写control层类：

package com.enjoypark.controller;
    
    import java.util.Date;
    import java.util.HashMap;
    import java.util.List;
    import java.util.Map;
    
    import org.apache.shiro.authz.annotation.RequiresPermissions;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.context.annotation.Scope;
    import org.springframework.stereotype.Controller;
    import org.springframework.util.StringUtils;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.ResponseBody;
    import org.springframework.web.bind.annotation.RequestMethod;
    import org.springframework.web.servlet.ModelAndView;
    
    import com.util.DateUtil;
    import com.util.SubmitMessage;
    
    import com.enjoypark.service.StudentService;
    import com.enjoypark.model.Student;
    
    /** * * @author wangPeng * @since 2018-10-11 * Student表的视图层 */
    
    @Controller
    @Scope("prototype")
    @SuppressWarnings("all")
    @RequestMapping("/student")
    public class StudentController { 
    
        @Autowired
        public StudentService studentService;
    
        //分页时对应的列表用户信息
        private List<Student> studentList; // 把jsp中的字段变量封装
        // 异步操作操作返回的信息
        private SubmitMessage submitMessage = new SubmitMessage();
        private Student student;//当前实体
    
        /** * 跳转列表页面 * @param request * @param model * @return */
        @RequiresPermissions("student:getStudent")
        @RequestMapping(value = "getStudent",method= RequestMethod.POST)
        public ModelAndView getStudent()
        { 
        	return new ModelAndView("/student");
        }
    
    
    	/** * 异步获取用户的信息列表 * @param String page,String rows * @return Map<String, Object> */
        @RequiresPermissions("student:getStudentBypage")
        @RequestMapping(value ="getStudentBypage",method= RequestMethod.POST)
        //@ResponseBody 表示返回的数据不是html标签格式，如json,xml等数据
      	@ResponseBody
        public Map<String, Object> getStudentBypage(String page,String rows,Student student)
        { 
    
            // 返回总记录数
            String total = Integer.toString(studentService.getAllCount(null).intValue());
    
            // 当前页
            int intPage;
            if (page == null || page.equals("0")){ 
                intPage = 1;
            }
            else{ 
                intPage = Integer.parseInt(page);
            }
    
            // 每页显示条数
            int number;
            if (rows== null || rows.equals("0")){ 
                number = 10;
            }else { 
                number = Integer.parseInt(rows);
            }
    
            // 每页的开始记录 第一页为1 第二页为number +1
            int start = (intPage - 1) * number;
    
            // 查询所有的用户信息
            studentList = studentService.getBypage(student, start, number);
    
            Map<String, Object> jsonMap = new HashMap<String, Object>();// 定义map
            jsonMap.put("total", total);// total键 存放总记录数，必须的
            jsonMap.put("rows", studentList);// rows键 存放每页记录 list
    
            return jsonMap;
        }
    
    	/** * 根据Id删除 * * @return */
        @RequiresPermissions("student:deleteStudent")
        @RequestMapping(value="deleteStudent",method= RequestMethod.POST)
        @ResponseBody
        public SubmitMessage deleteSysuser(String studentID)
        { 
    		//获取删除成功的记录个数
    				int result=studentService.deleteByID(Integer.parseInt(studentID));
    
    
            if(result>0){ 
        		submitMessage.setSuccess(true);
        		submitMessage.setInfo("删除成功");
        	}else{ 
        		submitMessage.setSuccess(false);
        		submitMessage.setInfo("数据库记录不存在");
        	}
    
            return submitMessage;
        }
    
        /** * 修改或新增前查询 * * @return */
        @RequestMapping(value="saveorupdateStudentBefore",method= RequestMethod.GET)
        public ModelAndView saveorupdateStudentBefore(String studentID)
        { 
        	ModelAndView modelAndView=new ModelAndView();
        	if(!StringUtils.isEmpty(studentID)){ 
        		student = studentService.getByID(Integer.parseInt(studentID));
        	}
    
            //设置前台接收的实体
            modelAndView.addObject("student",student);
            //设置页面视图
            modelAndView.setViewName("studentAdd");
            return modelAndView;
        }
    
         /** * 根据页面传递的信息，保存或修改数据库信息 * * @return */
        @RequiresPermissions("student:saveorupdateStudent")
        @RequestMapping(value="saveorupdateStudent",method= RequestMethod.POST)
        @ResponseBody
        public SubmitMessage saveorupdateSysuser(Student student)
        { 
    		boolean isSave = student.getId() == null || student.getId().equals(0);
    
            String strtime = DateUtil.formatDateByFormat(new Date(),DateUtil.DATETIME_FORMAT2);
    
            int result=0;
            if (isSave){ 
                result=studentService.saveStudent(student);
            }
            else{ 
               result=studentService.updateStudent(student);
            }
    
    
            if(result>0){ 
        		submitMessage.setSuccess(true);
        		submitMessage.setInfo("删除成功");
        	}else{ 
        		submitMessage.setSuccess(false);
        		submitMessage.setInfo("数据库记录不存在");
        	}
    
            return submitMessage;
        }
    
    }

1.  效果测试：  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3BlbmdnZXJoZQ_size_16_color_FFFFFF_t_70_pic_center 1]

# 源码地址： #

1.  获取完整源码地址： [https://download.csdn.net/download/penggerhe/11670196][https_download.csdn.net_download_penggerhe_11670196]
2.  公众号关注，免费领取：  
    ![在这里插入图片描述][20200904111728607.png_pic_center]

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[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3BlbmdnZXJoZQ_size_16_color_FFFFFF_t_70_pic_center 1]: /images/20221123/bcc2f863c9e84e2ea741d6c2302071d8.png
[https_download.csdn.net_download_penggerhe_11670196]: https://download.csdn.net/download/penggerhe/11670196
[20200904111728607.png_pic_center]: /images/20221123/5b0364fa02e74ed7a55c1fa6c0308f3e.png