mongo判断某些字段上有没有索引，进行动态创建

IndexOptions:
 private boolean background;
    private boolean unique;
    private String name;
    private boolean sparse;
    private Long expireAfterSeconds;
    private Integer version;
    private Bson weights;
    private String defaultLanguage;
    private String languageOverride;
    private Integer textVersion;
    private Integer sphereVersion;
    private Integer bits;
    private Double min;
    private Double max;
    private Double bucketSize;
    private Bson storageEngine;
    private Bson partialFilterExpression;
    private Collation collation;
    private Bson wildcardProjection;
    private boolean hidden;