MyBatis的经典案例

    1.首先我们先了解Mybatis的一些jar包

    ---和项目框架

     

    2.接下来就看看mybatis的配置文件(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>
     <!-- 别名 -->
     <typeAliases >
     <package name="cn.happy.entity"/>
     </typeAliases>
     
    <environments default="development">
        <environment id="development">
            <!-- 使用jdbc的事务 -->
            <transactionManager type="JDBC" />
            <!-- 使用自带的连接池 -->
            <dataSource type="POOLED">
                <property name="driver" value="oracle.jdbc.OracleDriver" />
                <property name="url" value="jdbc:oracle:thin:@localhost:1521:orcl" />
                <property name="username" value="happy" />
                <property name="password" value="1" />
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <!-- 连接小配置 -->
        <mapper resource="cn/happy/dao/StudentDAO.xml" />
    </mappers>
</configuration>

 

    3.在dao层的小配置(StudentDAO.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="cn.happy.dao">

    <!-- 添加 -->
    <insert id="insertStudent"> insert into student(stuno,stuname,stuage,studate) values(ssm.nextval,#{stuname},#{stuage},#{studate}) <selectKey keyProperty="stuno" resultType="int"> select SSM.CURRVAL from dual </selectKey>
    </insert>
    <!-- 查询所有 -->
    <select id="findAll" resultType="Student"> select * from student </select>

    <!-- 模糊查询 -->
    <select id="findAllLike" resultType="Student">
        <!-- 不管参数为什么都可以 -->
         <!--select * from student where stuname like concat('%',#{stuname},'%')--> 
          <!-- 字符串 -->
         <!--  select * from student where  stuname like '%${value}%' -->
         <!-- 对象 --> select * from student where  stuname like '%${stuname}%'
    </select>

    <!--删除学生 -->

    <delete id="delStudent"> delete from student where stuno=#{id}<!-- #{id}随便写，起到一个占位的作用 -->
    </delete>

</mapper>

 

 

     4.entity层实体类(Student)

 

package cn.happy.entity; import java.util.Date; public class Student { private int stuno; private String stuname; private int stuage; private Date studate; public String toString() { return "Student [stuno=" + stuno + ", stuname=" + stuname + ", stuage="
                + stuage + ", studate=" + studate + "]"; } public int getStuno() { return stuno; } public void setStuno(int stuno) { this.stuno = stuno; } public String getStuname() { return stuname; } public void setStuname(String stuname) { this.stuname = stuname; } public int getStuage() { return stuage; } public void setStuage(int stuage) { this.stuage = stuage; } public Date getStudate() { return studate; } public void setStudate(Date studate) { this.studate = studate; } }

 

 

   5.dao层(IStudentDAO)

 

package cn.happy.dao;

import java.io.IOException;
import java.util.List;

import cn.happy.entity.Student;

public interface IStudentDAO {

    /*
     * 添加学生信息
     */
    public int addStu(Student stu) throws IOException;
    
    /*
     * 查询所有
     */
    public List<Student> findAll() throws IOException;
    
    /*
     * 模糊查询
     */
    public List<Student> findAlllike(Student stu) throws IOException;
    
    /*
     * 模糊查询字符串
     */
    public List<Student> findAlllikebstuname(String stuname) throws IOException;
    
    /*
     * 删除
     */
    public int delStudent(int id) throws IOException;
}

 

 

   6.dao层下的impl层(IStudentDAOImpl)

 

package cn.happy.dao.impl; import java.io.IOException; import java.util.List; import org.apache.ibatis.session.SqlSession; import cn.happy.dao.IStudentDAO; import cn.happy.entity.Student; import cn.happy.util.MybatisUtil; public class IStudentDAOImpl implements IStudentDAO{ /* * session成员变量 */ SqlSession session; /* * 添加 * (non-Javadoc) * @see cn.happy.dao.IStudentDAO#addStu(cn.happy.entity.Student) */
    public int addStu(Student stu) throws IOException { //获取session 
        session = MybatisUtil.getSession(); //添加insert
        int result = session.insert("insertStudent", stu); //添加事物
 session.commit(); //关闭session
 session.close(); return result; } /* * 查询所有 * (non-Javadoc) * @see cn.happy.dao.IStudentDAO#fandAll() */
    public List<Student> findAll() throws IOException { //获取session
         session = MybatisUtil.getSession(); List<Student> list = session.selectList("findAll"); //关闭session
 session.close(); return list; } /* * 模糊查询 * 1.参数为对象 * (non-Javadoc) * @see cn.happy.dao.IStudentDAO#findAll(cn.happy.entity.Student) */
    public List<Student> findAlllike(Student stu) throws IOException { //获取session
         session = MybatisUtil.getSession(); List<Student> list = session.selectList("findAllLike",stu); //关闭session
 session.close(); return list; } /* * 模糊查询 * 2.参数为字符串 * (non-Javadoc) * @see cn.happy.dao.IStudentDAO#findAll(cn.happy.entity.Student) */
    public List<Student> findAlllikebstuname(String stuname) throws IOException { //获取session
         session = MybatisUtil.getSession(); System.out.println("222"); List<Student> list = session.selectList("findAllLike",stuname); System.out.println("333"); //关闭session
 session.close(); return list; } /* * 删除 */
    public int delStudent(int id) throws IOException { //获取session
         session = MybatisUtil.getSession(); int result = session.delete("delStudent", id); session.commit(); return result; } }

 

 

      7.util层的工具类(MybatisUtil )

 

package cn.happy.util; import java.io.IOException; import java.io.Reader; import org.apache.ibatis.io.Resources; import org.apache.ibatis.session.SqlSession; import org.apache.ibatis.session.SqlSessionFactory; import org.apache.ibatis.session.SqlSessionFactoryBuilder; /** * 工具类 * @author Happy * */
public class MybatisUtil { private static String config="mybatis-config.xml"; static Reader reader; static{ try { reader= Resources.getResourceAsReader(config); } catch (IOException e) { e.printStackTrace(); } } private static SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(reader); //提供一个可以获取到session的方法
    public static SqlSession getSession() throws IOException{ // 1.1 openSession到底做了什么
           SqlSession session = factory.openSession(); System.out.println("3333"); return session; } }

 

 

   8. 日志信息配置文件(log4j.properties)

 

### direct log messages to stdout ### log4j.appender.stdout=org.apache.log4j.ConsoleAppender log4j.appender.stdout.Target=System.out log4j.appender.stdout.layout=org.apache.log4j.PatternLayout log4j.appender.stdout.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L - %m%n ### direct messages to file mylog.log ### log4j.appender.file=org.apache.log4j.FileAppender log4j.appender.file.File=c\:mylog.log log4j.appender.file.layout=org.apache.log4j.PatternLayout log4j.appender.file.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L - %m%n ### set log levels - for more verbose logging change 'info' to 'debug' ### 
//记录cn.happy.dao包下的信息 log4j.logger.cn.happy.dao=trace, stdout

 

 

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