今天在做的事情：

4.Interface和ServiceImpl分开

之前逻辑一直都写在 DAO 里面，也曾感觉到修改起来很麻烦，搜索了一下这个步骤的关键词之后终于明白了。

DAO：负责直接操作数据库，里面只做原子级别的操作（增删改查）

Service：负责编写业务逻辑，使用 DAO 里面编写好的接口。

这样终于把业务逻辑剥离开了。

DAO 层的接口如下：

public interface DiscipleDao {
    List<Disciple> query(Disciple disciple);
    int insert(Disciple disciple);
    int update(Disciple disciple);
    int delete(int id);
}

DAO 的实现：

public class DiscipleDaoImpl extends SqlSessionDaoSupport implements DiscipleDao {


    @Override
    public List<Disciple> query(Disciple disciple){
        SqlSession sqlSession = this.getSqlSession();
        List<Disciple> discipleList = null;
        try {
            discipleList = sqlSession.selectList("mapper.DiscipleDao.query", disciple);
        }catch (DataAccessException e){
            System.out.println(e);
        }
        return discipleList;
    }

    @Override
    public int insert(Disciple disciple){
        SqlSession sqlSession = this.getSqlSession();
        int result = -1;
        try {
            result = sqlSession.insert("mapper.DiscipleDao.insert", disciple);
        }catch (DataAccessException e){
            System.out.println(e);
        }
        return result;
    }

    @Override
    public int update(Disciple disciple){
        SqlSession sqlSession = this.getSqlSession();
        int result = -1;
        try {
            result = sqlSession.update("mapper.DiscipleDao.update", disciple);
        }catch (DataAccessException e){
            System.out.println(e);
        }
        return result;
    }

    @Override
    public int delete(int id){
        SqlSession sqlSession = this.getSqlSession();
        int result = -1;
        try {
            result = sqlSession.delete("mapper.DiscipleDao.delete", id);
        }catch (DataAccessException e){
            System.out.println(e);
        }
        return result;
    }

}

业务代码（Service）我定为以下操作：

（a）报名弟子的增删改查

（b）根据名字或者学号查找日报链接

这里满足的步骤 8.添加数据返回ID，删除或更新数据返回True/False

public interface Service {
    List<Disciple> query(Disciple disciple);
    int insert(Disciple disciple);
    boolean update(Disciple disciple);
    boolean delete(int id);
    String queryForLink(Map<String,String> name_OR_id);
}

service 的实现：

public class ServiceImpl implements Service {

    private DiscipleDao discipleDao = new DiscipleDaoImpl();

    @Override
    public List<Disciple> query(Disciple disciple){
        return discipleDao.query(disciple);
    }

    @Override
    public int insert(Disciple disciple){
        return discipleDao.insert(disciple);
    }

    @Override
    public boolean update(Disciple disciple){
        return discipleDao.update(disciple) == 1 ? true: false;
    }

    @Override
    public boolean delete(int id){
        return discipleDao.delete(id) == 1 ? true: false;
    }


    @Override
    public String queryForLink(Map<String, String> name_OR_id){
        Disciple disciple = new Disciple();

        if (!name_OR_id.isEmpty()){
            disciple.setStudent_name(name_OR_id.get("name"));

            if (name_OR_id.containsKey("id")){
                int id = 0;

                try {
                    id = Integer.parseInt(name_OR_id.get("id"));
                }catch (NumberFormatException e){
                    return "The value of 'id' is not Integer.";
                }
                disciple.setStudent_id(id);
            }

            List<Disciple> discipleList = discipleDao.query(disciple);
            if (discipleList.size() == 1){
                return discipleList.get(1).getDaily_report();
            }
            else {
                return "Too many context.";
            }

        }
        else {
            return "Empty Map.";
        }
    }
}

spring 的配置：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:p="http://www.springframework.org/schema/p"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/context
       http://www.springframework.org/schema/context/spring-context.xsd
       http://www.springframework.org/schema/aop
       http://www.springframework.org/schema/aop/spring-aop.xsd
       http://www.springframework.org/schema/cache
       http://www.springframework.org/schema/cache/spring-cache.xsd
       http://www.springframework.org/schema/tx
       http://www.springframework.org/schema/tx/spring-tx.xsd">

    <!-- 配置数据库相关参数properties的属性：${url} -->
    <context:property-placeholder location="classpath:db.properties" />
    <!--配置c3p0连接池-->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="${jdbc.driver}"></property>
        <property name="jdbcUrl" value="${jdbc.url}"></property>
        <property name="user" value="${jdbc.username}"></property>
        <property name="password" value="${jdbc.password}"></property>
    </bean>
    <!--配置sqlSqlSessionFactory-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <!--注入mybatis核心配置文件-->
        <property name="configLocation" value="mybatis-config.xml"></property>
        <!--注入数据源-->
        <property name="dataSource" ref="dataSource"></property>
    </bean>
    <!--配置DiscipleDaoImpl，注入sqlSessionFactory-->
    <bean id="discipleDao" class="cn.mogeek.dao.DiscipleDaoImpl">
        <property name="sqlSessionFactory" ref="sqlSessionFactory"></property>
    </bean>
</beans>

测试的时候一直跑不通，打印出来的 sqlsession 一直是空的，暂时还没找出原因来，今天一直卡在这里。

感觉是 bean 里面给 DaoImpl 注入 sqlSessionFactory 出问题了，也说不准，先提交了日报，慢慢排查····