JPA Criteria API:LEFT JOIN上的多个条件

我有一个类似于以下的联接引用，其第一个联接表达式是由JPA API自动构造的.

I have a join reference like following for which the first join expression is constructed by the JPA API automatically.

CriteriaBuilder cb = entityManager.getCriteriaBuilder();
CriteriaQuery<Tuple> c = cb.createTupleQuery();
Root<Demand> demands = c.from(Demand.class);
Join<Demand, Metadata> joinMetadata = demands.join("metadatas", JoinType.LEFT);

但是，我想向我的joinMetadata添加一个附加条件，例如Metadata.type ="AFFECTATION_KEY"，但我不知道如何.

but, I would like to add an aditional condition to my joinMetadata like Metadata.type="AFFECTATION_KEY" but I don't know how.

非常感谢您的帮助