在Spring Mongo中作为嵌套文档进行项目

您可以使用以下聚合。

AggregationOperation project = Aggregation.project().         and("Contrat").nested(Fields.fields("Field1","Field2")).         and("Formule").nested(Fields.fields("Field3","Field4"));AggregationOperation project2 = Aggregation.project().         and("Contrats").nested(Fields.fields("Contrat","Formule")).AggregationOperation out = Aggregation.out("test");Aggregation aggregation = Aggregation.newAggregation(project, project2, out);mongoTemplate.aggregate(aggregation, "<nameOfInitialCollection>", Class.class);