当我们使用spring mybatis Mapper 自动扫描接口机制，生成Dao ，Mybatis 可以映射自动生成Mapper ，和Bean,XMl 文件。Service实现类可以通过注入相应的Mapper 即可调用Mapper中的方法，但是如果在controller 层或者其他Service类引入其他Service类，想调用自动生成的Mapper方法时，需要在Service 重新封装方法，才可以调用基础Mapper 方法，这就很麻烦。所以在此，构造公用的Service 父类，所有子类继承，即可调用Mapper 原生生成的方法，从而达到在Service中控制事务，并且不用ServiceImpl 实现类，重新封装方法
BaseService 接口，接口的方法和自动生成的Mapper 相对应
package com.ancoin.offical.service.base;
import java.util.List;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.session.RowBounds;
public interface BaseService<T> {
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_coin_info
*
* @mbg.generated
*/
long countByExample(Object ex);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_coin_info
*
* @mbg.generated
*/
int deleteByExample(Object ex);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_coin_info
*
* @mbg.generated
*/
int deleteByPrimaryKey(Object Id);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_coin_info
*
* @mbg.generated
*/
int insert(T entity);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_coin_info
*
* @mbg.generated
*/
int insertSelective(T entity);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_coin_info
*
* @mbg.generated
*/
List<T> selectByExampleWithRowbounds(Object ex, RowBounds rowBounds);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_coin_info
*
* @mbg.generated
*/
List<T> selectByExample(Object ex);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_coin_info
*
* @mbg.generated
*/
T selectByPrimaryKey(Object Id);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_coin_info
*
* @mbg.generated
*/
int updateByExampleSelective(T record, Object example);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_coin_info
*
* @mbg.generated
*/
int updateByExample(T record, Object example);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_coin_info
*
* @mbg.generated
*/
int updateByPrimaryKeySelective(T record);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_coin_info
*
* @mbg.generated
*/
int updateByPrimaryKey(T entity);
}
BaseServiceImpl 实现类
package com.ancoin.offical.service.base.impl;
import java.lang.reflect.ParameterizedType;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.apache.ibatis.session.RowBounds;
import org.apache.ibatis.session.SqlSession;
import org.mybatis.spring.mapper.MapperFactoryBean;
import org.springframework.util.StringUtils;
import com.ancoin.offical.config.SpringContextAware;
import com.ancoin.offical.service.base.BaseService;
/**
*
* @author LZH 2018-02-24
*
* @param <T>
*/
public abstract class BaseServiceImpl<T> implements BaseService<T>{
private Class<T> entityclass;
private String NameSpace;
private SqlSession sqlSession;
public BaseServiceImpl() {
entityclass =(Class<T>)((ParameterizedType)this.getClass().getGenericSuperclass()).getActualTypeArguments()[0];
try {
NameSpace = "com.ancoin.offical.dao.def."+entityclass.getSimpleName()+"Mapper.";
String beanName = StringUtils.uncapitalize(entityclass.getSimpleName()+"MapperEx");
System.out.println(beanName);
MapperFactoryBean mapperFactoryBean = SpringContextAware.getBean("&"+beanName);
sqlSession = mapperFactoryBean.getSqlSession();
} catch (Exception e) {
e.printStackTrace();
}
}
@Override
public long countByExample(Object ex) {
Object obj = sqlSession.selectOne(NameSpace+"countByExample", ex);
if(obj==null)return 0;
else {
return (long) obj;
}
}
@Override
public int deleteByExample(Object ex) {
return sqlSession.delete(NameSpace+"deleteByExample", ex);
}
@Override
public int deleteByPrimaryKey(Object Id) {
return sqlSession.delete(NameSpace+"deleteByPrimaryKey", Id);
}
@Override
public int insert(Object entity) {
return sqlSession.insert(NameSpace+"insert", entity);
}
@Override
public int insertSelective(Object entity) {
return sqlSession.insert(NameSpace+"insertSelective", entity);
}
@Override
public List selectByExampleWithRowbounds(Object ex, RowBounds rowBounds) {
return sqlSession.selectList(NameSpace+"selectByExampleWithRowbounds", ex, rowBounds);
}
@Override
public List<T> selectByExample(Object ex) {
return sqlSession.selectList(NameSpace+"selectByExample", ex);
}
@Override
public T selectByPrimaryKey(Object Id) {
return sqlSession.selectOne(NameSpace+"selectByPrimaryKey",Id);
}
@Override
public int updateByExampleSelective(Object record, Object example) {
Map params = new HashMap();
params.put("record", record);
params.put("example", example);
return sqlSession.update(NameSpace+"updateByExampleSelective", params);
}
@Override
public int updateByExample(Object record, Object example) {
Map params = new HashMap();
params.put("record", record);
params.put("example", example);
return sqlSession.update(NameSpace+"updateByExample", params);
}
@Override
public int updateByPrimaryKeySelective(Object record) {
return sqlSession.update(NameSpace+"updateByPrimaryKeySelective", record);
}
@Override
public int updateByPrimaryKey(Object entity) {
return sqlSession.update(NameSpace+"updateByPrimaryKey", entity);
}
}
这里的NameSpace 是相应类下面的xml 文件配置的NameSpace ,配置不一样，这里的值不一样，哟有一定的规律。beanName这里表示MapperFactoryBean 给每个Mapper生成的动态代理实现，Mapper 在扫描实例化时，会给每个Mapper生成一个MapperFactoryBean 代理实现类，如果不知道，可以 改一下 ，改成MapperFactoryBean mapperFactoryBean = SpringContextAware.getBean(MapperFactoryBean .class); 让它报错，就可以知道当前有多少个Mapper 代理实现类。
我这里在前面加“&”是因为报错时有带&。上面写法注意是为了拿到当前的sqlSession，只要拿到sqlSession 下面一切都好办
