org.springframework.data.jpa.support.PageableUtils Maven / Gradle / Ivy

package org.springframework.data.jpa.support;

import java.lang.reflect.Field;
import java.util.Map;

import org.springframework.data.domain.Pageable;
import org.springframework.data.domain.Sort;
import org.springframework.data.domain.Sort.Order;
import org.springframework.data.querydsl.QSort;
import org.springframework.util.CollectionUtils;
import org.springframework.util.LinkedCaseInsensitiveMap;
import org.springframework.util.ReflectionUtils;
import org.springframework.util.StringUtils;

import com.querydsl.core.types.OrderSpecifier;
import com.querydsl.core.types.dsl.ComparableExpressionBase;

public class PageableUtils {
  public static boolean pageable(Pageable pageable, String property) {
    if (pageable != null && pageable.getSort() != null && StringUtils.hasText(property)) {
      for (Order order : pageable.getSort()) {
        if (property.equalsIgnoreCase(order.getProperty())) {
          return true;
        }
      }
    }
    return false;
  }

  public static Pageable pageable(Pageable pageable, Map> expressions) {
    if (pageable != null && pageable.getSort() != null && !CollectionUtils.isEmpty(expressions)) {
      Sort sort = null;
      for (Order order : pageable.getSort()) {
        if (expressions.containsKey(order.getProperty())) {
          OrderSpecifier orderSpecifier;
          switch (order.getDirection()) {
          case ASC:
            orderSpecifier = expressions.get(order.getProperty()).asc();
            break;
          case DESC:
            orderSpecifier = expressions.get(order.getProperty()).desc();
            break;
          default:
            throw new UnsupportedOperationException();
          }
          switch (order.getNullHandling()) {
          case NATIVE:
            break;
          case NULLS_FIRST:
            orderSpecifier = orderSpecifier.nullsFirst();
            break;
          case NULLS_LAST:
            orderSpecifier = orderSpecifier.nullsLast();
            break;
          default:
            throw new UnsupportedOperationException();
          }
          sort = sort == null ? new QSort(orderSpecifier) : sort.and(new QSort(orderSpecifier));
        }
      }
      if (sort != null) {
        Field field = ReflectionUtils.findField(pageable.getClass(), "sort");
        ReflectionUtils.makeAccessible(field);
        ReflectionUtils.setField(field, pageable, sort);
      }
    }
    return pageable;
  }

  /**
   * @see java.util.TreeMap
   * @see java.lang.String#CASE_INSENSITIVE_ORDER
   */
  public static Pageable pageable(Pageable pageable, ComparableExpressionBase... expressions) {
    Map> map = new LinkedCaseInsensitiveMap>();
    for (ComparableExpressionBase expression : expressions) {
      map.put(String.valueOf(expression), expression);
    }
    return pageable(pageable, map);
  }

  public static Pageable pageable(Pageable pageable, Sort sort) {
    if (pageable != null && sort != null) {
      Field field = ReflectionUtils.findField(pageable.getClass(), "sort");
      ReflectionUtils.makeAccessible(field);
      ReflectionUtils.setField(field, pageable, sort);
    }
    return pageable;
  }
}