Overview
Version is a simple immutable record that encapsulates a version number as a long value. It’s commonly used for optimistic locking and version tracking in domain entities.
Package: com.softwarearchetypes.common
Source: /common/src/main/java/com/softwarearchetypes/common/Version.java:3
Constructor
public record Version(long value)
The version number. Can be any valid long value including negative numbers.
Static Factory Methods
initial
public static Version initial()
A Version instance with value 0
Version version = Version.initial();
assert version.value() == 0L;
public static Version of(long value)
A Version instance with the specified value
Version version = Version.of(42L);
assert version.value() == 42L;
// Works with any long value
Version maxVersion = Version.of(Long.MAX_VALUE);
Version minVersion = Version.of(Long.MIN_VALUE);
Version negativeVersion = Version.of(-1L);
Methods
Returns the version number.
Example:
Version version = Version.of(123L);
long value = version.value();
assert value == 123L;
Record Methods
As a Java record, Version automatically provides:
equals(Object) - Two Versions are equal if they have the same valuehashCode() - Consistent with equalstoString() - Returns a string representation like "Version[value=123]"
Example:
Version v1 = Version.of(10L);
Version v2 = Version.of(10L);
Version v3 = Version.of(20L);
assert v1.equals(v2); // true
assert v1.hashCode() == v2.hashCode(); // true
assert !v1.equals(v3); // false
assert v1.toString().equals("Version[value=10]");
Usage Examples
Initial Version
Version version = Version.initial();
assert version.value() == 0L;
// Equivalent to
Version sameVersion = Version.of(0L);
assert version.equals(sameVersion);
Version Comparison
Version current = Version.of(5L);
Version expected = Version.of(5L);
if (current.equals(expected)) {
// Versions match - proceed with update
}
Incrementing Version
Version current = Version.of(10L);
Version next = Version.of(current.value() + 1);
assert next.value() == 11L;
Optimistic Locking Pattern
public void updateEntity(Entity entity, Version expectedVersion) {
if (!entity.getVersion().equals(expectedVersion)) {
throw new OptimisticLockException(
"Version mismatch: expected " + expectedVersion.value() +
" but was " + entity.getVersion().value()
);
}
// Perform update
entity.setVersion(Version.of(expectedVersion.value() + 1));
repository.save(entity);
}
