后端开发-Mybatis开发之一

2018-12-29

Mybatis简单开发：我是在eclipse上进行Java项目开发

目录结构如下：

    

内容如下：

mysql.sql: 用于创建测试用的数据库以及表； 可以直接导入mysql，通过navicat工具或命令行；

create database chapter3;

use chapter3;

create table t_role (
id int(12) auto_increment,
role_name varchar(60) not null,
note varchar(256) null,
primary key(id)
);

insert into t_role(role_name, note) values('role_name_1', 'note_1');

mybatis-config.xml 如下:

<?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">
 <!-- MyBatis配置文件 -->
<configuration>
  <!-- 配置 -->  
  <properties resource="db.properties">
  </properties>
    <typeAliases><!-- 别名 -->
        <typeAlias alias="role" type="com.learn.ssm.chapter3.pojo.Role" />
    </typeAliases>
    <!-- 数据库环境 -->
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC" />
            <dataSource type="POOLED">
                <!--引入db.properties配置文件前 -->
                <!-- <property name="driver" value="com.mysql.jdbc.Driver"/> <property 
                    name="url" value="jdbc:mysql://localhost:3306/chapter3"/> <property name="username" 
                    value="root"/> <property name="password" value="root"/> -->
                <!--引入db.properties配置文件后 -->
                <property name="driver" value="${jdbc.driver}" />
                <property name="url" value="${jdbc.url}" />
                <property name="username" value="${jdbc.name}" />
                <property name="password" value="${jdbc.password}" />
            </dataSource>
        </environment>
    </environments>
    <!-- 映射文件 -->
    <mappers>
        <mapper resource="com/learn/ssm/chapter3/mapper/RoleMapper.xml" />
        <mapper class="com.learn.ssm.chapter3.mapper.RoleMapper2" />
    </mappers>
</configuration>

db.properties

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/chapter3
jdbc.name=root
jdbc.password=123456

log4j.properties

#日志配置文件
log4j.rootLogger=DEBUG , stdout
log4j.logger.org.mybatis=DEBUG
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p %d %C: %m%n

 Chapter3Main.java

package com.learn.ssm.chapter3.main;
import org.apache.ibatis.session.SqlSession;
import org.apache.log4j.Logger;

import com.learn.ssm.chapter3.mapper.RoleMapper;
import com.learn.ssm.chapter3.mapper.RoleMapper2;
import com.learn.ssm.chapter3.pojo.Role;
import com.learn.ssm.chapter3.utils.SqlSessionFactoryUtils;

/**
 * 程序入口
 * @author zc
 * @date 2018-12-29
 */
public class Chapter3Main {

    public static void main(String[] args) {
        testRoleMapper();
        testRoleMapper2();
        
    }
    
    
    private static void testRoleMapper() {
        Logger log = Logger.getLogger(Chapter3Main.class);
        SqlSession sqlSession = null;
        try {
            sqlSession = SqlSessionFactoryUtils.openSqlSession();
            RoleMapper roleMapper = sqlSession.getMapper(RoleMapper.class);
            Role role = roleMapper.getRole(1L);
            log.info(role.getRoleName());
        } finally {
            if (sqlSession != null) {
                sqlSession.close();
            }
        }
    }
    
    //ע��SQL����
    private static void testRoleMapper2() {
        Logger log = Logger.getLogger(Chapter3Main.class);
        SqlSession sqlSession = null;
        try {
            sqlSession = SqlSessionFactoryUtils.openSqlSession();
            RoleMapper2 roleMapper2 = sqlSession.getMapper(RoleMapper2.class);
            Role role = roleMapper2.getRole(1L);
            log.info(role.getRoleName());
        } finally {
            if (sqlSession != null) {
                sqlSession.close();
            }
        }
    }
    
}

RoleMapper.java

package com.learn.ssm.chapter3.mapper;
import java.util.List;

import org.apache.ibatis.annotations.Param;

import com.learn.ssm.chapter3.pojo.PageParams;
import com.learn.ssm.chapter3.pojo.Role;
import com.learn.ssm.chapter3.pojo.RoleParams;
public interface RoleMapper {
    public int insertRole(Role role);
    public int deleteRole(Long id);
    public int updateRole(Role role);
    public Role getRole(Long id);
    public List<Role> findRoles(String roleName);
    //多个参数
    public List<Role> findRolesByAnnotation(@Param("roleName") String rolename,
            @Param("note") String note);
    public List<Role> findRolesByMix(@Param("params") RoleParams roleParams,
            @Param("page") PageParams pageParams);
}

RoleMapper2.java

package com.learn.ssm.chapter3.mapper;

import org.apache.ibatis.annotations.Select;

import com.learn.ssm.chapter3.pojo.Role;

public interface RoleMapper2 {
    
    @Select("select id, role_name as roleName, note from t_role where id=#{id}")
    public Role getRole(Long id);
}

RoleMapper.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.learn.ssm.chapter3.mapper.RoleMapper">

    <insert id="insertRole" parameterType="role">
        insert into t_role(role_name, note) values(#{roleName}, #{note})
    </insert>

    <delete id="deleteRole" parameterType="long">
        delete from t_role where id= #{id}
    </delete>

    <update id="updateRole" parameterType="role">
        update t_role set role_name = #{roleName}, note = #{note} where id= #{id}
    </update>

    <select id="getRole" parameterType="long" resultType="role">
        select id,
        role_name as roleName, note from t_role where id = #{id}
    </select>

    <select id="findRoles" parameterType="string" resultType="role">
        select id, role_name as roleName, note from t_role
        where role_name like concat('%', #{roleName}, '%')
    </select>
    
    
    <select id="findRolesByAnnotation" resultType="role">
    select id, role_name as roleName, note from t_role
    where role_name like concat('%', #{roleName}, '%')
    and note like concat('%', #{note}, '%')
  </select>
  
  <select id="findRolesByBean" parameterType="com.learn.ssm.chapter3.pojo.RoleParams" resultType="role">
    select id, role_name as roleName, note from t_role
    where role_name like concat('%', #{roleName}, '%')
    and note like concat('%', #{note}, '%')
  </select>
  
  <select id="findRolesByMix" resultType="role">
    select id, role_name as roleName, note from t_role
    where role_name like concat('%', #{params.roleName}, '%')
    and note like concat('%', #{params.note}, '%')
    limit #{page.start}, #{page.limit}
  </select>
</mapper>

Role.java

package com.learn.ssm.chapter3.pojo;

/**
 * POJO对象
 * @author zc
 *
 */
public class Role {

    private Long id;
    private String roleName;
    private String note;

    /** setter and getter **/
    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getRoleName() {
        return roleName;
    }

    public void setRoleName(String roleName) {
        this.roleName = roleName;
    }

    public String getNote() {
        return note;
    }

    public void setNote(String note) {
        this.note = note;
    }

}

PageParams .java

package com.learn.ssm.chapter3.pojo;

public class PageParams {
    private int start;
    private int limit;
    
    public int getStart() {
        return start;
    }
    public void setStart(int start) {
        this.start = start;
    }
    public int getLimit() {
        return limit;
    }
    public void setLimit(int limit) {
        this.limit = limit;
    }
}

RoleParams .java

package com.learn.ssm.chapter3.pojo;

public class RoleParams {
    private String roleName;
    private String note;
    public String getRoleName() {
        return roleName;
    }
    public void setRoleName(String roleName) {
        this.roleName = roleName;
    }
    public String getNote() {
        return note;
    }
    public void setNote(String note) {
        this.note = note;
    }
}

SqlSessionFactoryUtils.java

package com.learn.ssm.chapter3.utils;

import java.io.IOException;
import java.io.InputStream;

import org.apache.ibatis.datasource.pooled.PooledDataSource;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.mapping.Environment;
import org.apache.ibatis.session.Configuration;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.apache.ibatis.transaction.TransactionFactory;
import org.apache.ibatis.transaction.jdbc.JdbcTransactionFactory;

import com.learn.ssm.chapter3.mapper.RoleMapper;
import com.learn.ssm.chapter3.mapper.RoleMapper2;
import com.learn.ssm.chapter3.pojo.Role;

/**
 * 一个工具类，用于创建SqlSessionFactory和获取SqlSession对象
 * @author zc
 *
 */
public class SqlSessionFactoryUtils {

    private final static Class<SqlSessionFactoryUtils> LOCK = SqlSessionFactoryUtils.class;

    private static SqlSessionFactory sqlSessionFactory = null;

    private SqlSessionFactoryUtils() {
    }

    public static SqlSessionFactory getSqlSessionFactory() {
        synchronized (LOCK) {
            if (sqlSessionFactory != null) {
                return sqlSessionFactory;
            }
            String resource = "mybatis-config.xml";
            InputStream inputStream;
            try {
                inputStream = Resources.getResourceAsStream(resource);
                sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
            } catch (IOException e) {
                e.printStackTrace();
                return null;
            }
            return sqlSessionFactory;
        }
    }
    
    
    //��������SqlSessionFactory
    public static SqlSessionFactory getSqlSessionFactory2() {
        synchronized (LOCK) {
            //���ݿ����ӳ���Ϣ
            PooledDataSource dataSource = new PooledDataSource();
            dataSource.setDriver("com.mysql.jdbc.Driver");
            dataSource.setUsername("root");
            dataSource.setPassword("123456");
            dataSource.setUrl("jdbc:mysql://localhost:3306/chapter3");
            dataSource.setDefaultAutoCommit(false);
            //����MyBatis��JDBC����ʽ
            TransactionFactory transactionFactory = new JdbcTransactionFactory();
            Environment environment = new Environment("development", transactionFactory, dataSource);
            //����Configuration����
            Configuration configuration = new Configuration(environment);
            //ע��һ��MyBatis�����ı���
            configuration.getTypeAliasRegistry().registerAlias("role", Role.class);
            //����һ��ӳ����
            configuration.addMapper(RoleMapper.class);
            configuration.addMapper(RoleMapper2.class);
            //ʹ��SqlSessionFactoryBuilder����SqlSessionFactory
            sqlSessionFactory = 
                new SqlSessionFactoryBuilder().build(configuration);
            return sqlSessionFactory;     
        }
    }

    public static SqlSession openSqlSession() {
        if (sqlSessionFactory == null) {
            getSqlSessionFactory();
        }
        return sqlSessionFactory.openSession();
    }
}

1. 先引入mybatis和mysql相关jar包

2. 然后将mysql.sql导入到mysql中

3.运行