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#54 - Added a project for MongoDB examples using Java 8 features.

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This initial version of the example projects demonstrates the usage and mapping behavior of Java 8 Streams in repositories. The test cases oppose a plain List based query method with one that uses a Stream and shows how the former pulls all data into memory first and the iteration is done over the pre-populated list. The execution of the Stream based method in contrast shows that the individual elements are read and converted while iterating the stream.
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Thomas Darimont
2015-03-02 18:06:31 +01:00
committed by Oliver Gierke
parent 6597d7ca95
commit 73be2fcddb
8 changed files with 237 additions and 1 deletions
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# Spring Data MongoDB - Java 8 examples
This project contains samples of Java 8 specific features of Spring Data (MongoDB).
## Support for JDK 8's `Stream` for repository methods
Repository methods can use a Java 8 `Stream` as a return type which will cause the reading of the results and the to-object-conversion of the `DBObject` to happen while iterating over the stream.
```java
public interface PersonRepository extends CrudRepository<Person, String> {
@Override
List<Person> findAll();
//Custom Query method returning a Java 8 Stream
@Query("{}")
Stream<Person> findAllByCustomQueryWithStream();
}
```
The test cases in `PersonRepositoryIntegrationTest` oppose a plain `List` based query method with one that uses a `Stream` and shows how the former pulls all data into memory first and the iteration is done over the pre-populated list. The execution of the `Stream`-based method in contrast shows that the individual elements are read and converted while iterating the stream.