[SPARK-51557][SQL][TESTS] Add tests for TIME data type in Java API

### What changes were proposed in this pull request?

This PR adds tests for the TIME data type in Spark's Java API, covering Dataset and UDF functionality with `java.time.LocalTime`:
  - Adding a dataset filter operations with `java.time.LocalTime` (there is not a similar one for `TimestampType`).
  - UDF registration and execution with TimeType in udf8Test - the same as the `udf7Test()` for `TimestampType`.
  - `testLocalTimeEncoder()` already existed for `TimestampType` parity.

### Why are the changes needed?

As part of the TIME data type SPIP (SPARK-51162), we need test coverage in the Java API for Datasets and UDFs.

### Does this PR introduce _any_ user-facing change?

No

### How was this patch tested?

  Added new test methods:
  - `JavaDatasetSuite.testLocalTimeFilter` - Tests Dataset filter with `LocalTime`
  - `JavaUDFSuite.udf8Test` - Tests UDF registration and execution with `LocalTime`

![Screenshot 2025-07-07 at 4 00 58 AM](https://github.com/user-attachments/assets/160f207e-e3e5-45a2-ac5d-35b55a76215e)
![Screenshot 2025-07-07 at 3 59 24 AM](https://github.com/user-attachments/assets/c18bf26d-a6ef-4445-95b0-a67566ac9fa0)

  I executed the tests themselves locally and also ran `./build/mvn test-compile -pl sql/core` to test compilation.

### Was this patch authored or co-authored using generative AI tooling?

No

Closes apache#51387 from fartzy/SPARK-51557_Add_tests_for_TIME_data_type_in_Java_API.

Authored-by: Mike Artz <fartzy@hotmail.com>
Signed-off-by: Max Gekk <max.gekk@gmail.com>

Author: Mike Artz

sql/core/src/test/java/test/org/apache/spark/sql/JavaDatasetSuite.java

@@ -812,6 +812,26 @@ public void testLocalTimeEncoder() {
     Assertions.assertEquals(data, ds.collectAsList());
   }
 
+  @Test
+  public void testLocalTimeFilter() {
+    Encoder<LocalTime> encoder = Encoders.LOCALTIME();
+    List<LocalTime> data = Arrays.asList(
+      LocalTime.of(9, 30, 45),
+      LocalTime.of(14, 10, 10),
+      LocalTime.of(22, 10, 10)
+    );
+    Dataset<LocalTime> ds = spark.createDataset(data, encoder);
+
+    Dataset<LocalTime> filtered = ds.filter(
+      (FilterFunction<LocalTime>) time -> time.isAfter(LocalTime.of(12, 0, 0))
+    );
+    List<LocalTime> expectedFiltered = Arrays.asList(
+      LocalTime.of(14, 10, 10),
+      LocalTime.of(22, 10, 10)
+    );
+    Assertions.assertEquals(expectedFiltered, filtered.collectAsList());
+  }
+
   public static class KryoSerializable {
     String value;
 

sql/core/src/test/java/test/org/apache/spark/sql/JavaUDFSuite.java

@@ -19,6 +19,7 @@
 
 import java.io.Serializable;
 import java.time.LocalDate;
+import java.time.LocalTime;
 import java.util.List;
 
 import org.apache.spark.sql.catalyst.FunctionIdentifier;
@@ -34,6 +35,7 @@
 import org.apache.spark.sql.classic.SparkSession;
 import org.apache.spark.sql.api.java.UDF2;
 import org.apache.spark.sql.types.DataTypes;
+import org.apache.spark.sql.types.TimeType;
 
 // The test suite itself is Serializable so that anonymous Function implementations can be
 // serialized, as an alternative to converting these anonymous classes to static inner classes;
@@ -136,6 +138,15 @@ public void udf7Test() {
     }
   }
 
+  @Test
+  public void udf8Test() {
+    spark.udf().register(
+        "plusTwoHours",
+        (java.time.LocalTime lt) -> lt.plusHours(2), new TimeType(6));
+    Row result = spark.sql("SELECT plusTwoHours(TIME '09:10:10')").head();
+    Assertions.assertEquals(LocalTime.of(11, 10, 10), result.get(0));
+  }
+
   @Test
   public void sourceTest() {
     spark.udf().register("stringLengthTest", (String str) -> str.length(), DataTypes.IntegerType);