Mybatis接口映射

Posted 2021-11-28 qiyiguoandqijiguo

前面Mybatis是直接通过Dao层与数据交互,更好的方法是Mybatis通过接口映射方式与数据交互

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1.在项目中添加maven支持(即pom.xml下添加支持)

<!--
   在pom.xml下配置
-->
<!-- mybatis核心包 -->
     <dependencies>
        <!-- mybatis核心包 -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.3.0</version>
        </dependency>
        <!-- mysql驱动包 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.40</version>
        </dependency>
        <!-- junit测试包 -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.11</version>
            <scope>test</scope>
        </dependency>
        <!-- 日志文件管理包 -->
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>1.7.12</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>1.7.12</version>
        </dependency>
    </dependencies>

Maven要按照大佬博客说的配置,接下来file-->settings-->Maven-->Maven home directory设置为Maven安装包路径
然后user settings file 设置为安装包路径\conf\settings.xml

---

2.创建实体类UserInfo

package com.qf.mybatisdemo.pojo;

import java.util.List;

public class UserInfo {
    int userId;
    String password;
    String email;
    String phone;
    String icon;
    String userName;
    String name;
    List<RoleInfo> roleInfoList;

    public int getUserId() {
        return userId;
    }

    public void setUserId(int userId) {
        this.userId = userId;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getPhone() {
        return phone;
    }

    public void setPhone(String phone) {
        this.phone = phone;
    }

    public String getIcon() {
        return icon;
    }

    public void setIcon(String icon) {
        this.icon = icon;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public String getName() {
        return name;
    }

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

    public List<RoleInfo> getRoleInfoList() {
        return roleInfoList;
    }

    public void setRoleInfoList(List<RoleInfo> roleInfoList) {
        this.roleInfoList = roleInfoList;
    }

    @Override
    public String toString() {
        return "UserInfo{" +
                "userId=" + userId +
                ", password='" + password + '\'' +
                ", email='" + email + '\'' +
                ", phone='" + phone + '\'' +
                ", icon='" + icon + '\'' +
                ", userName='" + userName + '\'' +
                ", name='" + name + '\'' +
                ", roleInfoList=" + roleInfoList +
                '}';
    }
}

---

3.创建mapper包，mapper下创建UserMapper接口

package com.qf.mybatisdemo.mapper;

import com.qf.mybatisdemo.pojo.UserInfo;
import com.qf.mybatisdemo.userVo.UserVo;

import java.util.List;

public interface UserInfoMapper {
    <!--查询-->
    public UserVo userInfoLogin(UserVo userVo);
    <!--public int addUserInfo(UserVo userVo);-->
    <!--public int updateUserInfobyId(UserVo userVo);-->
    <!--public int deleteUserInfo(UserVo userVo);-->
    <!--public List<UserInfo> getUserInfo(UserInfo userInfo);-->
}

---

4.resource资源包下创建mapper包，mapper下创建UserMapper.xml

<?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.qf.mybatisdemo.mapper.UserInfoMapper"><!--注意此处-->


    <select id="UserInfoLogin" parameterType="userVo" resultType="userVo">
      select * from userinfo
        <where>
            <if test="userName != null and userName == ''">
              and username=#{userName}
            </if>
            <if test="password != null and password == ''">
              and password =#{password}
            </if>
        </where>
    </select>

</mapper>

---

namespace一般绑定对应的文件的全路径，

• 有三种全路径：

  • 第一种：namespace绑定实体类的全路径：当namespace绑定的是实体类的全路径时，其实现数据持久化的方式为无代理模式实现数据持久化。需要手动实现dao层的接口。

      <mapper namespace="com.qf.pojo.User"></namespace>

  • 第二种：namespace绑定dao层接口的全路径：当namespace绑定的是dao接口的全路径时，其实现数据持久化的方式为有代理模式实现数据持久化。即会自动产生代理，自动实现数据的持久化，不需要实现dao层的接口。

      <mapper namespace="com.qf.dao.userDao"></namespace>

  • 第三种：namespace绑定的是mapper接口对应的sql.xml文件是，其也是有代理模式自动实现数据持久化。但mapper接口对应的sql.xml文件名必须保持一致才能自动实现数据持久化。

    <mapper namespace="com.qf.mapper.UserInfoMapper"></namespace>

---

5.resource下创建log4j.properties，配置log4j日志

log4j.rootLogger=DEBUG,CONSOLE,file
#log4j.rootLogger=ERROR,ROLLING_FILE
#下面log4j.logger.com.qf.dao=debug 根据项目目录来改
log4j.logger.com.qf.dao=debug   
log4j.logger.com.ibatis=debug 
log4j.logger.com.ibatis.common.jdbc.SimpleDataSource=debug 
log4j.logger.com.ibatis.common.jdbc.ScriptRunner=debug 
log4j.logger.com.ibatis.sqlmap.engine.impl.SqlMapClientDelegate=debug 
#log4j.logger.java.sql.Connection=debug
#log4j.logger.java.sql.Statement=debug
#log4j.logger.java.sql.PreparedStatement=debug
#log4j.logger.java.sql.ResultSet=debug
log4j.logger.org.tuckey.web.filters.urlrewrite.UrlRewriteFilter=debug

######################################################################################
# Console Appender  \u65e5\u5fd7\u5728\u63a7\u5236\u8f93\u51fa\u914d\u7f6e
######################################################################################
log4j.appender.CONSOLE=org.apache.log4j.ConsoleAppender
log4j.appender.Threshold=error
log4j.appender.CONSOLE.Target=System.out
log4j.appender.CONSOLE.layout=org.apache.log4j.PatternLayout
log4j.appender.CONSOLE.layout.ConversionPattern= [%p] %d %c - %m%n


######################################################################################
# DailyRolling File  \u6bcf\u5929\u4ea7\u751f\u4e00\u4e2a\u65e5\u5fd7\u6587\u4ef6\uff0c\u6587\u4ef6\u540d\u683c\u5f0f:log2009-09-11
######################################################################################
log4j.appender.file=org.apache.log4j.DailyRollingFileAppender
log4j.appender.file.DatePattern=yyyy-MM-dd
log4j.appender.file.File=log.log
log4j.appender.file.Append=true
log4j.appender.file.Threshold=error
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=%d{yyyy-M-d HH:mm:ss}%x[%5p](%F:%L)%m%n


log4j.logger.com.opensymphony.xwork2=error

---

6.resource下创建mybatis-config.xml

<?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>
    <properties resource="mysql.properties"/>
    <settings>
        <!--全局性设置懒加载。如果设为‘false’，则所有相关联的都会被初始化加载,默认值为false-->
        <setting name="lazyLoadingEnabled" value="true"/>
        <!--当设置为‘true’的时候，懒加载的对象可能被任何懒属性全部加载。否则，每个属性都按需加载。默认值为true-->
        <setting name="aggressiveLazyLoading" value="false"/>
    </settings>
    <typeAliases>
        <!-- 将com.qf.mybatisdemo.pojo.User的替换成一个短的名字user-->
        <typeAlias type="com.qf.mybatisdemo.pojo.User" alias="user"/>
    </typeAliases>
    <!--对事务的管理和连接池的配置-->
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"></transactionManager>
            <dataSource type="POOLED"><!--POOLED：使用Mybatis自带的数据库连接池来管理数据库连接-->
                <property name="driver" value="${jdbc.driver}"/>
                <property name="url" value="${jdbc.url}"/>
                <property name="username" value="${jdbc.username}"/>
                <property name="password" value="${jdbc.password}"/>
            </dataSource>
        </environment>
    </environments>
    <!--resource下mapper的xml文件路径配置-->
    <mappers>
        <mapper resource="mapper/UserMapper.xml"/>
        <mapper resource="mapper/UserInfoMapper.xml"/>
        <!--<mapper resource="mapper/RoleInfoMapper.xml"/>-->
        <!--<mapper resource="mapper/MenuInfoMapper.xml"/>-->
    </mappers>

</configuration>

7.resource下创建mysql.propertis

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://127.0.0.1:3306/1901mybatis?useUnicode=true&characterEncoding=utf8&characterSetResults=utf8
jdbc.username=root
jdbc.password=root

---

8.创建测试类

package com.qf.mybatisdemo;

import com.qf.mybatisdemo.dao.BaseDao;
import com.qf.mybatisdemo.mapper.UserInfoMapper;
import com.qf.mybatisdemo.pojo.UserInfo;
import com.qf.mybatisdemo.userVo.UserVo;
import org.apache.ibatis.session.SqlSession;
import org.junit.Test;
import java.util.List;

public class MybatisDemo2 {

    BaseDao baseDao = new BaseDao();<!--调用前面的BaseDao曾-->
    SqlSession sqlSession = baseDao.getSqlSession();
    UserInfoMapper userInfoMapper = sqlSession.getMapper(UserInfoMapper.class);

    @Test
    public void UserInfoLogin() {
        UserVo userVo =new UserVo();
        UserVo userVo2 =new UserVo();
        userVo.setPassword("123456");
        userVo.setUserName("liaomou");
        userVo2 = userInfoMapper.userInfoLogin(userVo);
        System.out.println(userVo2);
    }
}