Modernize date handling with Java 21 pattern matching

[robfrank]

Overview

Modernize date handling code in DateUtils.java and BinaryTypes.java using Java 21 pattern matching switch expressions.

Part of Epic #2968

Goals

• 43% reduction in cyclomatic complexity
• 23% code reduction with improved clarity
• 100% explicit null safety with pattern matching
• Replace verbose if-else chains with exhaustive switch expressions
• Migrate from wildcard to explicit imports

Files to Change

DateUtils.java

Location: engine/src/main/java/com/arcadedb/utility/DateUtils.java

Methods to modernize:

• getNanos(Object obj)
• getMicros(Object obj)
• getMillis(Object obj)
• getSeconds(Object obj)
• precisionFromDateType(byte type)
• dateTypeToPrecision(ChronoUnit precision)

BinaryTypes.java

Location: engine/src/main/java/com/arcadedb/serializer/BinaryTypes.java

Methods to modernize:

• precisionFromDateType(byte type)

Implementation Pattern

// Before: verbose if-else chain
public static int getNanos(final Object obj) {
  if (obj == null)
    throw new IllegalArgumentException("Object is null");
  else if (obj instanceof LocalDateTime time)
    return time.getNano();
  else if (obj instanceof ZonedDateTime time)
    return time.getNano();
  // ...
}

// After: clean pattern-matching switch
public static int getNanos(final Object obj) {
  return switch (obj) {
    case null -> throw new IllegalArgumentException("Object is null");
    case LocalDateTime time -> time.getNano();
    case ZonedDateTime time -> time.getNano();
    case Instant instant -> instant.getNano();
    default -> throw new IllegalArgumentException("Cannot extract nanos from object of type '" + obj.getClass() + "'");
  };
}

Validation

# Compile
mvn compile -pl engine

# Run unit tests
mvn test -pl engine -Dtest=*DateUtils*
mvn test -pl engine -Dtest=*Binary*

# Run integration test that depends on these changes
mvn test -pl server -Dtest=RemoteDateIT

Success Criteria

• No compilation errors
• All DateUtils unit tests pass
• All BinaryTypes tests pass
• RemoteDateIT passes (after bug fix in separate issue)
• Code follows Java 21 patterns
• Explicit imports replace wildcards

Time Estimate

50 minutes total

• DateUtils.java: 30 minutes
• BinaryTypes.java: 20 minutes

Risk Level

LOW - Straightforward refactoring with good test coverage

Documentation

See PORTING_PLAN_IT_TEST_IMPROVEMENTS.md - Phase 2 for detailed instructions.

Related Issues

Part of Epic: #2968