mboog.support.mapper.ReadMapper Maven / Gradle / Ivy

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package mboog.support.mapper;

import mboog.support.bean.Page;
import mboog.support.example.PaginationAble;
import mboog.support.exceptions.ExampleException;
import mboog.support.exceptions.MapperException;

import java.util.Collections;
import java.util.List;
import java.util.Objects;

/**
 * @param  PrimaryKey
 * @param       Model
 * @param     Example
 * @author LiYi
 */
public interface ReadMapper
        extends BaseMapper {

    long countByExample(Example example);

    List selectByExample(Example example);

    default Model selectByExampleSingleResult(Example example) {
        List results = selectByExample(example);
        int size = (results != null ? results.size() : 0);
        if (size == 0) {
            return null;
        }
        if (results.size() > 1) {
            throw new MapperException("data results must single result");
        }
        return results.iterator().next();
    }

    Model selectByPrimaryKey(PrimaryKey id);

    default List selectByExample(Example example, long page, long size) {
        if (Objects.isNull(example)) {
            throw new ExampleException("Example can't null");
        }
        if (example instanceof PaginationAble) {
            PaginationAble temp = (PaginationAble) example;
            if ("Oracle".equalsIgnoreCase(temp.getDatabaseType())) {
                temp.setLimitStart((page - 1) * size);
                temp.setLimitEnd(page * size);
            } else {
                temp.setLimitStart((page - 1) * size);
                temp.setLimitEnd(size);
            }

            return selectByExample(example);
        } else {
            throw new ExampleException("Example must PaginationAble");
        }

    }

    /**
     * Pagination selectByExample
     *
     * @param example NOT NULL
     * @param page    page_no
     * @param size    page_size
     * @return Page
     */
    default Page selectPageByExample(Example example, long page, long size) {
        if (Objects.isNull(example)) {
            throw new ExampleException("Example can't null");
        }
        if (example instanceof PaginationAble) {
            PaginationAble temp = (PaginationAble) example;
            String orderByClause = temp.getOrderByClause();
            temp.setOrderByClause(null);
            long count = countByExample(example);
            List list = null;
            if (count > 0) {
                temp.setOrderByClause(orderByClause);
                list = selectByExample(example, page, size);
            } else {
                list = Collections.emptyList();
            }
            return new Page(list, count, page, size);
        } else {
            throw new ExampleException("Example must PaginationAble");
        }

    }

}