起别名的maven

首先：重新定的实体类
cn.javabs.entity.op.UserDao

package cn.javabs.entity;
import java.util.Date;
/**
 * 持久化类
 * */
public class User {    			    
	private  Integer userId; 
    private  String userName;   
    private String userAddress;   
    private String  Usersex;  
    private Date userBirthday; 
    //  按键盘 alt + inster   生成getter方法和setter方法 
      @Override    public String toString() {     
         return "User{" +             
            "userId=" + userId +            
            ", userName='" + userName + '\'' +         
            ", userAddress='" + userAddress + '\'' +          
            ", Usersex='" + Usersex + '\'' +            
            ", userBirthday=" + userBirthday +              
              '}';   
           }  
   public Integer getUserId() { return userId; }  
   public void setUserId(Integer userId) 
   		{ this.userId = userId; }   
   public String getUserName() { return userName;} 
   public void setUserName(String userName) 
   		{ this.userName = userName;} 
   public String getUserAddress() { return userAddress;} 
   public void setUserAddress(String userAddress)
   		 { this.userAddress = userAddress;    }   
    public String getUsersex() { return Usersex; }
    public void setUsersex(String usersex)
    		 { Usersex = usersex;}
    public Date getUserBirthday() { return userBirthday; }
    public void setUserBirthday(Date userBirthday) 
    {this.userBirthday = userBirthday;}
    }

同时定义了个集合的id,如果查非常多的id，就需要像
cn.javabs.Queryvo

package cn.javabs.entity;
import java.util.List;

public class Queryvo {   

 private List<Integer> ids;// 可能有很多id    

	public List<Integer> getIds(){ return ids;}  

    public void setIds(List<Integer> ids)
    		{  this.ids = id; }
@Override
    public String toString() {
        return "Queryvo{" +
                "ids=" + ids +
                '}';
    }
}

放在一个集合里好方便查找，快速，提高效率

cn.javabs.dao.UserDao

`<?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">

		<!-- namespace 表示命名空间 -->
	<mapper namespace="cn.javabs.dao.UserDao">
	
	<!--        配置：查询结果的字段名称与实体中书名名 的对应关系-->
		<resultMap id="userMap" type="user">
	<!--    1.主键字段的对应-->   
		 	<id property="userId" column="id"/>
	 <!-- 2.非主键（普通）字段的对应    -->  
	  		 <result property="userName" column="username"/>
	   <!--    <result property="userSex" column="sex"/>-->  
	    	 <result property="userAddress" column="address"/>
	     <!--    <result property="Usersex" column="sex"/>--> 
	     	<result property="userAddress" column="address"/> 
	     	<result property="userBirthday" column="bitthday"/>
		 </resultMap>  

				  <!-- SQL语句 -->
         <!--    全部查询-->   
          <select id="findAllUser"  resultType="user">  
                select * from  user   
           </select>

		<!--    添加-->    
		<insert id="add" parameterType="user">  
		      <!--          
		        keyProperty  是持久化类的编号  对应的是 user 类的id   
		        keyColumn  是数据库中的字段名称 对应user 表的id           
		        resultType   是 返回结果 因为返回是编号 因此int         
		         erder       是 在插入语句之前before还是 ofter     
		        -->      
		         <selectKey keyProperty="id" keyColumn="id" resultType="user" order="AFTER">         
		           select LAST_INSERT_ID();     
		         </selectKey>    

    insert  into user (username, address,sex,birthday)   
     values (#{username},#{ address},#{sex},#{birthday})  
    </insert>

		<!--    寻找很多的ids-->  

  <select id="findUserIds" parameterType="Queryvo" resultMap="userMap">  
       select  * from  user       
        <where>           
         	<if test="ids != null  and ids.size()>0" >               
         	<foreach collection="ids" item="uid" open="and t_id in(" close=")" separator=",">              
            #{uid}              
           </foreach>          
           </if>       
         </where>   
 </select>

			<!--   批量删除 -->
    <delete id="delUserBYIds" parameterType="Queryvo">
        delete from  user
                <where>
            <if test="ids != null and ids.size()>0">
                <foreach collection="ids" open="and id in (" close= ")" separator="," item="id">
                    #{id}
                </foreach>
            </if>
        </where>
    </delete>
 </mapper>`

resource-cn.java.properties文件

java.driver=com.mysql.jdbc.Driver
java.url=jdbc:mysql://localhost:3306/mybatis
java.username=root
java.password=root`

resources-mybatis-config.xml 文件

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" 
"http://mybatis.org/dtd/mybatis-3-config.dtd">

<configuration>
<!--        1.读取数据库信息-->    
<properties resource="jdbc.properties"/><!--    类型别名-->  

  <typeAliases>
  <!--        typeAlias 配置别名 只对这个类配置了-->
  <!--        <typeAlias type="cn.javabs.entity.User">-->
  <!--              
   	 <typeAliastype="cn.javabs.entity.User"> </typeAlias>
    -->
  			<!--对entity包下的所有类配置-->        
  			<package name="cn.javabs.entity"/>    
  </typeAliases> 
  			   
  			<!-- 1.配置环境，默认的环境id为mysql -->   
  	   <environments default="mysql">        
  			 <!-- 1.2.配置id为mysql的数据库环境 -->       
  	  <environment id="mysql">           
  			   <!-- 使用JDBC的事务管理 -->           
  	  <transactionManager type="JDBC"/>   
  		             
  			  <!-- 配置数据库连接信息(数据库连接池) -->           
  			  <dataSource type="POOLED">
  			   			<!-- 数据库驱动-->              
  			       <property name="driver" value="${java.driver}"/>
  			     		<!-- 连接数据库-->               
  			        <property name="url" value="${java.url}"/>
  			      		<!-- 数据库的账户名称-->               
  			       <property name="username" value="${java.username}"/>
  			     		<!-- 数据库的密码-->               
  			       <property name="password" value="${java.password}"/>            
  			     
  			 </dataSource>        
  	 </environment>
   </environments>   

		 <!-- 2.配置Mapper的位置 -->   
		  <mappers>
		  <!-- cn.javabs.dao 自动加载所有映射文件  有点问题-->
		  <!--        <package name="mapper/*"/>-->       
		   <mapper resource="mapper\UserDao.xml"/
		   </mappers>
</configuration>