如何在Morphia / MongoDB Java中创建复合唯一索引？

Question

假设我有一个MongoDB实体，如下所示：

@Entity(value = "car")
public class Car {
   public String manufacturer;
   public String model;
   public String year;
   public Double price;
}

我想添加一个索引，使得对manufacturer,model,year是独一无二的。

当我尝试以下注释 - @Indexes(@Index(value="manufacturer,model,year, unique=true)) - 它可以工作。但它会引发以下错误：

[WARN] (main) : DatastoreImpl - This index on 'Car' is using deprecated configuration options.  Please update to use the fields value on @Index: @org.mongodb.morphia.annotations.Index(unique=true, dropDups=false, background=false, name=, value=manufacturer, model, year, expireAfterSeconds=-1, disableValidation=false, sparse=false, fields=[], options=@org.mongodb.morphia.annotations.IndexOptions(unique=false, dropDups=false, background=false, name=, expireAfterSeconds=-1, disableValidation=false, language=, languageOverride=, sparse=false))

如何正确配置索引？

Answer 1

请尝试以下注释

@Entity(value = "car")
@Indexes(@Index(fields = { @Field("manufacturer"), @Field("model"), @Field("year") }, options = @IndexOptions(unique = true)))
public class Car {
   public String manufacturer;
   public String model;
   public String year;
   public Double price;
}