一、使用采用数据映射器（MapperFactoryBean）的方式注解实现整合mybatis

不用写mybatis映射文件，采用注解方式提供相应的sql语句和输入参数，项目目录如下

第一步、导入jar包

            
                 
                  
                      
       
        src/main/java
                       
                           
        
         **/*.xml
                        
                   
                  
                      
       
        src/main/resources
                       
                           
        
         **/*.properties
                            
        
         **/*.xml
                        
                   
              
         
        
            
                 
      
       aopalliance
                  
      
       aopalliance
                  
      
       1.0
              
             
             
                 
      
       org.aspectj
                  
      
       aspectjweaver
                  
      
       1.6.9
              
             
             
                 
      
       commons-dbcp
                  
      
       commons-dbcp
                  
      
       1.4
              
             
                 
      
       commons-logging
                  
      
       commons-logging
                  
      
       1.2
              
             
                 
      
       commons-pool
                  
      
       commons-pool
                  
      
       1.6
              
             
                 
      
       org.apache.logging.log4j
                  
      
       log4j
                  
      
       2.6.1
              
             
                 
      
       org.mybatis
                  
      
       mybatis
                  
      
       3.4.1
              
             
                 
      
       org.mybatis
                  
      
       mybatis-spring
                  
      
       2.0.1
              
             
                 
      
       mysql
                  
      
       mysql-connector-java
                  
      
       5.1.6
              
             
                 
      
       org.springframework
                  
      
       spring-context
                  
      
       4.3.6.RELEASE
              
             
                 
      
       org.springframework
                  
      
       spring-jdbc
                  
      
       4.3.6.RELEASE
              
             
                 
      
       org.springframework
                  
      
       spring-tx
                  
      
       4.3.6.RELEASE
              
             
                 
      
       c3p0
                  
      
       c3p0
                  
      
       0.9.1.2
                  
      
       compile
              
         
    

第二步、创建学生实体类

package com.cc.entity;public class Student {    private  int id;    private  String stuno;    private  String name;    private  String classid;    public int getId() {        return id;    }    public void setId(int id) {        this.id = id;    }    public String getStuno() {        return stuno;    }    public void setStuno(String stuno) {        this.stuno = stuno;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public String getClassid() {        return classid;    }    public void setClassid(String classid) {        this.classid = classid;    }    @Override    public String toString() {        return "Student{" +                "id=" + id +                ", stuno='" + stuno + '\'' +                ", name='" + name + '\'' +                ", classid='" + classid + '\'' +                '}';    }}

第三步、创建Mapper接口，在接口中用注解的方式实现sql语句

package com.cc.dao;import com.cc.entity.Student;import org.apache.ibatis.annotations.Param;import org.apache.ibatis.annotations.Select;import java.util.List;public interface StudentMapper {    @Select("select * from student where id=#{id}")    Student findById(@Param("id") int id);    @Select("select * from student")    List
    
      selectAll();}
    

那么还有一个问题，我想在注解中实现动态查询那怎么办？？？案例如下

@Mapperpublic interface DemandCommentMapper extends BaseMapper
    
     {    @Select("SELECT "            + "a.id as 'id',a.create_date as 'createDate',a.content as 'content',"            + "a.parent_id as 'parentId',a.first_comment_id as 'firstCommentId',"            + "b.id as 'fromUser.id',b.realname as 'fromUser.realname',b.avatar as 'fromUser.avatar',"            + "c.id as 'toUser.id',c.realname as 'toUser.realname',c.avatar as 'toUser.avatar' "            + "FROM t_demand_comment a "            + "LEFT JOIN t_user b ON b.id = a.from_uid "            + "LEFT JOIN t_user c ON c.id = a.to_uid "            + "WHERE a.demand_id = #{demandId} "            + "ORDER BY a.create_date ASC"            + "LIMIT #{startNo},#{pageSize}")    public List
     
       listDemandComment(@Param("demandId") Long demandId, 　　　　　　　　　　　　　　　　　　　　　　　　　　　　　@Param("startNo") Integer pageNo, 　　　　　　　　　　　　　　　　　　　　　　　　　　　　　@Param("pageSize") Integer pageSize);
     
    

这样整个语句是写死的，如果我想根据pageNo与pageSize是否为空来判断是否需要分页，该怎么做呢?如果使用xml来配置的话可以用

    
       LIMIT #{startNo},#{pageSize}
    

如果是用 这种该如何做呢？方法：用script标签包围，然后像xml语法一样书写

@Mapperpublic interface DemandCommentMapper extends BaseMapper
    
     {    @Select("
     ")    public List
     
       listDemandComment(@Param("demandId") Long demandId, 　　　　　　　　　　　　　　　　　　　　　　　　　　　　　@Param("startNo") Integer pageNo, 　　　　　　　　　　　　　　　　　　　　　　　　　　　　　@Param("pageSize") Integer pageSize);
     
    

项目实例

@Select("")    public List
    
      getTaobao(@Param("status") Integer status);
    

在这里还碰到一个问题就是报错：Caused by: org.apache.ibatis.reflection.ReflectionException: There is no getter for property named 'status' in 'class java.lang.Interger'

出现原因：这里出现的问题是在DAO方法中定义的参数 与 实体中定义的属性不一致 导致的。

解决方案：dao层加@Param("userId")注解即可（实例中就是加上@Param("status")）

public List<DictItem> selectKeyByUserId(@Param("userId") long userId);

第四步、在service层实现接口类

package com.cc.service;import com.cc.entity.Student;import java.util.List;public interface StudentService {    Student findById(int id);    List
    
      selectAll();}
    

package com.cc.service;import com.cc.dao.StudentMapper;import com.cc.entity.Student;import java.util.List;public class StudentServiceImpl implements StudentService {    private  StudentMapper studentMapper;    public void setStudentMapper(StudentMapper studentMapper) {        this.studentMapper = studentMapper;    }    @Override    public Student findById(int id) {        return (Student) studentMapper.findById(id);    }    @Override    public List
    
      selectAll() {        return studentMapper.selectAll();    }}
    

第五步、配置ApplicationContext.xml文件

第六步、配置db.properties文件

#mysql jdbc freshjdbc.driver=com.mysql.jdbc.Driverjdbc.url=jdbc:mysql://localhost:3306/fresh?useUnicode=true&characterEncoding=UTF-8jdbc.username=rootjdbc.password=root

第七步、测试类

import com.cc.entity.Student;import com.cc.service.StudentService;import com.cc.service.StudentServiceImpl;import org.junit.Test;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;import java.util.List;public class Testdemo1 {    @Test    public  void test(){         ApplicationContext ac=new ClassPathXmlApplicationContext("applicationContext.xml");         StudentService studentService =ac.getBean("studentService", StudentServiceImpl.class);         Student student=studentService.findById(5);         System.out.println(student);         List
    
      studentList=studentService.selectAll();         for (Student stu: studentList) {            System.out.println(stu);         }    }}
    

二、采用抽象类org.mybatis.spring.support.SqlSessionDaoSupport提供SqlSession

目录结构如下

第一步、导入jar包

            
                 
                  
                      
       
        src/main/java
                       
                           
        
         **/*.xml
                        
                   
                  
                      
       
        src/main/resources
                       
                           
        
         **/*.properties
                            
        
         **/*.xml
                        
                   
              
         
        
            
                 
      
       aopalliance
                  
      
       aopalliance
                  
      
       1.0
              
             
             
                 
      
       org.aspectj
                  
      
       aspectjweaver
                  
      
       1.6.9
              
             
             
                 
      
       commons-dbcp
                  
      
       commons-dbcp
                  
      
       1.4
              
             
                 
      
       commons-logging
                  
      
       commons-logging
                  
      
       1.2
              
             
                 
      
       commons-pool
                  
      
       commons-pool
                  
      
       1.6
              
             
                 
      
       org.apache.logging.log4j
                  
      
       log4j
                  
      
       2.6.1
              
             
                 
      
       org.mybatis
                  
      
       mybatis
                  
      
       3.4.1
              
             
                 
      
       org.mybatis
                  
      
       mybatis-spring
                  
      
       2.0.1
              
             
                 
      
       mysql
                  
      
       mysql-connector-java
                  
      
       5.1.6
              
             
                 
      
       org.springframework
                  
      
       spring-context
                  
      
       4.3.6.RELEASE
              
             
                 
      
       org.springframework
                  
      
       spring-jdbc
                  
      
       4.3.6.RELEASE
              
             
                 
      
       org.springframework
                  
      
       spring-tx
                  
      
       4.3.6.RELEASE
              
             
                 
      
       Spring
                  
      
       Spring_mybatis_01
                  
      
       1.0-SNAPSHOT
                  
      
       compile
              
         
    

第二步、创建实体类

package cc.entity;public class Student {    private  int id;    private  String stuno;    private  String name;    private  String classid;    public int getId() {        return id;    }    public void setId(int id) {        this.id = id;    }    public String getStuno() {        return stuno;    }    public void setStuno(String stuno) {        this.stuno = stuno;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public String getClassid() {        return classid;    }    public void setClassid(String classid) {        this.classid = classid;    }    @Override    public String toString() {        return "Student{" +                "id=" + id +                ", stuno='" + stuno + '\'' +                ", name='" + name + '\'' +                ", classid='" + classid + '\'' +                '}';    }}

第三步、创建StudentDao接口，已经其实现类

package cc.dao;import com.cc.entity.Student;public interface StudentDao {    Student findById(int id);}

package cc.dao;import com.cc.dao.StudentDao;import com.cc.entity.Student;import org.mybatis.spring.support.SqlSessionDaoSupport;public class StudentImpl extends SqlSessionDaoSupport implements StudentDao {    @Override    public Student findById(int id) {        return (Student) getSqlSession().selectOne("com.cc.dao.StudentMapper.findById",id);    }}

第四步、创建映射器接口，已经其mapper配置文件

package cc.dao;import com.cc.entity.Student;public interface StudentMapper {    Student findById(int id);}

    
        
             SELECT * from student where id = #{id}    
    

第五步、实现ApplicationContext配置文件和mybatis核心配置文件

第六步、配置数据文件

#mysql jdbc freshjdbc.driver=com.mysql.jdbc.Driverjdbc.url=jdbc:mysql://localhost:3306/fresh?useUnicode=true&characterEncoding=UTF-8jdbc.username=rootjdbc.password=root

第七步、在test文件用junit4实现单元测试

import cc.dao.StudentImpl;import com.cc.entity.Student;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;public class Test {    @org.junit.Test    public  void test(){        ApplicationContext ac=new ClassPathXmlApplicationContext("applicationContext.xml");        StudentImpl stu=ac.getBean("studentDao", StudentImpl.class);        Student student=stu.findById(6);        System.out.println(student);    }}

三、采用接口org.apache.ibatis.session.SqlSession的实现类org.mybatis.spring.SqlSessionTemplate

这种平时都用的很少，所以这里我就不写了

四、采用扫描接口的方式实现Spring整合mybatis(最常用)

第一步、导入依赖配置

            
                 
                  
                      
       
        src/main/java
                       
                           
        
         **/*.xml
                        
                   
                  
                      
       
        src/main/resources
                       
                           
        
         **/*.properties
                            
        
         **/*.xml
                        
                   
              
         
        
            
                 
      
       aopalliance
                  
      
       aopalliance
                  
      
       1.0
              
             
             
                 
      
       org.aspectj
                  
      
       aspectjweaver
                  
      
       1.6.9
              
             
             
                 
      
       commons-dbcp
                  
      
       commons-dbcp
                  
      
       1.4
              
             
                 
      
       commons-logging
                  
      
       commons-logging
                  
      
       1.2
              
             
                 
      
       commons-pool
                  
      
       commons-pool
                  
      
       1.6
              
             
                 
      
       org.apache.logging.log4j
                  
      
       log4j
                  
      
       2.6.1
              
             
                 
      
       org.mybatis
                  
      
       mybatis
                  
      
       3.4.1
              
             
                 
      
       org.mybatis
                  
      
       mybatis-spring
                  
      
       2.0.1
              
             
                 
      
       mysql
                  
      
       mysql-connector-java
                  
      
       5.1.6
              
             
                 
      
       org.springframework
                  
      
       spring-context
                  
      
       4.3.6.RELEASE
              
             
                 
      
       org.springframework
                  
      
       spring-jdbc
                  
      
       4.3.6.RELEASE
              
             
                 
      
       org.springframework
                  
      
       spring-tx
                  
      
       4.3.6.RELEASE
              
             
                 
      
       Spring
                  
      
       Spring_mybatis_01
                  
      
       1.0-SNAPSHOT
                  
      
       compile
              
             
                 
      
       com.mchange
                  
      
       c3p0
                  
      
       0.9.5.2
              
             
                 
      
       log4j
                  
      
       log4j
                  
      
       1.2.12
              
         
    

第二步、编写实体类

package cc.entity;public class Student {    private  int id;    private  String stuno;    private  String name;    private  String classid;    public int getId() {        return id;    }    public void setId(int id) {        this.id = id;    }    public String getStuno() {        return stuno;    }    public void setStuno(String stuno) {        this.stuno = stuno;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public String getClassid() {        return classid;    }    public void setClassid(String classid) {        this.classid = classid;    }    @Override    public String toString() {        return "Student{" +                "id=" + id +                ", stuno='" + stuno + '\'' +                ", name='" + name + '\'' +                ", classid='" + classid + '\'' +                '}';    }}

第三步、配置StudentMapper接口

package cc.dao;import com.cc.entity.Student;public interface StudentMapper {    Student findById(int id);}

第四步、配置mybatis映射文件和核心配置文件

    
        
             SELECT * from student where id = #{id}    
    

第五步、配置数据库文件

#mysql jdbc freshjdbc.driver=com.mysql.jdbc.Driverjdbc.url=jdbc:mysql://localhost:3306/fresh?useUnicode=true&characterEncoding=UTF-8jdbc.username=rootjdbc.password=root

第六步、配置ApplicationContext.xml

第七步、编写测试类

import cc.service.StudentService;import com.cc.entity.Student;import org.junit.Test;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;public class Testone {    @Test    public void test(){        ApplicationContext ac=new ClassPathXmlApplicationContext("applicationContext.xml");        StudentService studentService = (StudentService) ac.getBean("studentService");        Student student=studentService.findById(4);        System.out.println(student);    }}