Reactor，布尔值返回对象

Question

我想根据模型名称创建一个新的集合。如果存在同名集合，则返回现有集合。如果没有，新创建的集合returns。我正在使用 ReactiveCrudRepository。我是反应新手。我在底层代码中收到此错误。我该怎么办？

public Mono<MongoCollection<Document>> constructDBCollection(String modelName) {
        return reactiveMongoOperations.collectionExists(modelName)
                .flatMap(exists -> exists ? reactiveMongoOperations.getCollection(modelName) : reactiveMongoOperations.createCollection(modelName, CollectionOptions.empty()
                .size(1024 * 1024)
                .capped()));
    }

Error The type of flatMap(java.util.function.Function>) is erroneous DBCollectionFactory.java /src/main/java/com/jagger/obls/factory/DBCollectionFactory.java:26

Error incompatible types: cannot infer type-variable(s) R
(argument mismatch; bad return type in lambda expression bad type in conditional expression
com.mongodb.reactivestreams.client.MongoCollection cannot be converted to reactor.core.publisher.Mono) DBCollectionFactory.java /src/main/java/com/jagger/obls/factory/DBCollectionFactory.java:26

Answer 1

根据 javadoc，getCollection 实际上是 returns MongoCollection<Document>，而不是它的 Mono。因此，将此调用包装在 Mono.just(reactiveMongoOperations.getCollection(modelName)) 中应该可以做到。

Reactor，布尔值返回对象

Reactor, Boolean by value Returned object

spring-data

spring-data-mongodb

spring-boot

project-reactor