sercoll

Java Collections declared Serializable

This Java library provides one way to deal with the problem that Java collection interfaces are not declared serializable. Without sercoll, the following code will cause the FindBugs warning Non-transient non-serializable instance field in serializable class (SE_BAD_FIELD):

public class MyObject implements Serializable {
  private static final long serialVersionUID = 1L;
  private String foo;
  private List<String> strings;  // FindBugs error
  // ... snip ...
}

This is correct, because List, Set, Map, and other standard Java collection classes do not implement Serializable, as they cannot know whether their elements are serializable or not.

So, while other solutions exist, such as using the concrete collection type, tricking the detector into not working for your class, or ignoring the warning, I believe the cleanest way is to make the declaration:

public class MyObject implements Serializable {
  private static final long serialVersionUID = 1L;
  private String foo;
  private SerializableList<String> strings;  // OK!
  // ... snip ...
}

Sercoll provides the interfaces such as SerializableList that are directly derived from the JDK classes, but add the serializability declaration. In addition to that, the required supplementary code is provided to successfully use the new interfaces in practice with little to no refactoring effort.

Prerequisites

Sercoll requires at least JDK 6. It has no dependencies on other libraries.

Status

This is work in progress. Sercoll is not yet complete (some classes are missing), and also poorly tested as yet. This notice will be updated once sercoll has stabilized sufficiently to be ready for production use.

Integration

Sercoll is distributed through Maven Central, so you can just use it in your build. Sercoll uses semantic versioning, so you can safely include the latest of a major version.

Gradle:

dependencies {
    compile group: 'com.thomasjensen.sercoll', name: 'sercoll', version: '0.+'
}

Maven:

<dependencies>
  <dependency>
    <groupId>com.thomasjensen.sercoll</groupId>
    <artifactId>sercoll</artifactId>
    <version>0.7.0</version>
  </dependency>
</dependencies>

Download: You can also download the JAR manually, of course.

Resources

Javadoc