MyBatis 3.4.5及以上涕刚，支持向@SelectProvider對(duì)象方法傳遞泛型,通過ProviderContext對(duì)象

一、通用Mapper

通過@InsertProvider,@UpdateProvider,@DeleteProvider 和@SelectProvider等注解實(shí)現(xiàn)

@SelectProvider示例

package com.my.world.common.mybatis.mapper;

import com.my.world.common.mybatis.provider.CommonSqlProvider;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.SelectProvider;

public interface CommonBaseMapper<T> {

    @SelectProvider(type = CommonSqlProvider.class, method = "selectById")
    T selectById(@Param("id") String id);

}

public class CommonSqlProvider {

    private Class getPoClass(ProviderContext providerContext) {
        Class mapperType = providerContext.getMapperType();
        ParameterizedType genericSuperclass = (ParameterizedType) mapperType.getGenericInterfaces()[0];
        return (Class) genericSuperclass.getActualTypeArguments()[0];
    }

    public String selectById(Map<String, Object> para, ProviderContext providerContext) {
        Class poClass = getPoClass(providerContext);
        Annotation annotation = poClass.getAnnotation(TableName.class);
        String tableName = annotation == null ? poClass.getName().toLowerCase() : ((TableName) annotation).value();
        String idName = null;
        SQL sql = new SQL();
        for (Field field : poClass.getDeclaredFields()) {
            String fieldName = DBUtil.humpToLine(field.getName());
            sql.SELECT(fieldName + " as "+field.getName());
            if (field.getAnnotation(ID.class) != null) {
                idName = fieldName;
            }
        }
        sql.FROM(tableName);
        sql.WHERE(idName+"=#{id}");

        return sql.toString();
    }
}

使用：

@Repository
public interface UserMapper extends CommonBaseMapper<User> {
}

二乙帮、通用Service

public abstract class CommonBaseService<T> {

    @Autowired
    private CommonBaseMapper<T> commonBaseMapper;

    public T selectById(String id) {
        return commonBaseMapper.selectById(id);
    }
}

三杜漠、通用Controller

public abstract class CommonBaseController<T> {
    @Autowired
    private CommonBaseMapper<T> commonBaseMapper;

    @RequestMapping(value = {"/{id}"}, method = RequestMethod.GET)
    public Object getUserById(@PathVariable("id") String id) {
        T po = commonBaseMapper.selectById(id);
        HashMap<String, Object> data = new HashMap<String, Object>(20);
        ObjectData objectData = new ObjectData();
        objectData.setData(po);
        return objectData;
    }
}