MongoDB中关于Criteria的各种查询实例(is、in、regex、gte、lte、elemMatch)

例如：实体中有一集合，包含三个元素，A、B、C，实现至少含有其中一个元素就可以查询到此实体的时候就需要使用elemMatch来进行查询

package cn.com.qiyitech.qiyibiz.model.item;

import cn.com.qiyitech.pfw.entity.PlatformAsset;
import cn.com.qiyitech.pfw.model.PlatformBaseFilter;
import cn.com.qiyitech.qiyibiz.entity.Item;
import cn.com.qiyitech.qiyibiz.entity.ItemFabric;
import cn.com.qiyitech.qiyibiz.entity.ItemOrder;
import cn.com.qiyitech.qiyibiz.entity.Shop;
import io.swagger.annotations.ApiModelProperty;
import lombok.Getter;
import lombok.Setter;
import org.springframework.data.mongodb.core.query.Criteria;

import java.util.Set;
@Setter
@Getter
public class ItemListFilter extends PlatformBaseFilter {

    @ApiModelProperty(value = "商品名称")
    private String name;

    @ApiModelProperty(value = "所属店铺ID")
    private Set owner;

    @ApiModelProperty(value = "幅宽最大值")
    private Integer maxWidthCloth;

    @ApiModelProperty(value = "幅宽最小值")
    private Integer minWidthCloth;

    @ApiModelProperty(value = "克重单位")
    private String weightUnit;

    @ApiModelProperty(value = "产品规格")
    private String[] specification;


    @Override
    public Criteria genCriteria() {
        Criteria criteria = new Criteria();
        if (specification != null && specification.length > 0)
            criteria = criteria.and(Item.FIELD_SPECIFICATION).elemMatch(new Criteria().in(specification));
        if (owner != null) 
            criteria = criteria.and(PlatformAsset.FIELD_OWNER).in(owner);
        if (name != null)
            criteria = criteria.and(PlatformAsset.FIELD_NAME).regex(".*" + name + ".*");
        if (minWidthCloth != null || maxWidthCloth != null) {
            if (minWidthCloth == null) {
                minWidthCloth = 0;
            }
            if (maxWidthCloth == null) {
                maxWidthCloth = Integer.MAX_VALUE;
            }
            criteria = criteria.and(Item.FIELD_WIDTH_CLOTH).gte(minWidthCloth).lte(maxWidthCloth);
        }
        if (weightUnit != null) 
            criteria = criteria.and(Item.FIELD_WEIGHT_UNIT).is(weightUnit);
        return criteria;
    }
}