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We now check whether an external Apache Cassandra instance is available at localhost:9042 and use it to run the examples. Otherwise, if no external Apache Cassandra instance is available, we start an embedded Cassandra instance.
22 lines
1014 B
Markdown
22 lines
1014 B
Markdown
# Spring Data Cassandra - Java 8 examples
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This project contains samples of Java 8 specific features of Spring Data (Cassandra).
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## Support for JDK 8's `Stream` for repository methods
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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 rows to happen while iterating over the stream.
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```java
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public interface PersonRepository extends CrudRepository<Person, String> {
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@Override
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List<Person> findAll();
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//Custom Query method returning a Java 8 Stream
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@Query("SELECT * FROM person")
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Stream<Person> findAllByCustomQueryWithStream();
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}
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```
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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.
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