GH-38511: [Java] Add getTransferPair(Field, BufferAllocator, CallBack…

…) for StructVector and MapVector (#38512)

### Rationale for this change
Missed impl of getTransferPair(Field, BufferAllocator, CallBack) for StructVector and MapVector

### What changes are included in this PR?

### Are these changes tested?
yes, added unit test.

### Are there any user-facing changes?

* Closes: #38511

Authored-by: Ivan Chesnov <ivan.chesnov@dremio.com>
Signed-off-by: David Li <li.davidm96@gmail.com>

java/vector/src/main/java/org/apache/arrow/vector/complex/MapVector.java

@@ -146,6 +146,11 @@ public TransferPair getTransferPair(String ref, BufferAllocator allocator, CallB
  return new TransferImpl(ref, allocator, callBack);
  }
 
+ @Override
+ public TransferPair getTransferPair(Field field, BufferAllocator allocator, CallBack callBack) {
+ return new TransferImpl(field, allocator, callBack);
+ }
+
  @Override
  public TransferPair makeTransferPair(ValueVector target) {
  return new MapVector.TransferImpl((MapVector) target);

java/vector/src/main/java/org/apache/arrow/vector/complex/StructVector.java

@@ -246,6 +246,15 @@ public TransferPair getTransferPair(Field field, BufferAllocator allocator) {
  allowConflictPolicyChanges), false);
  }
 
+ @Override
+ public TransferPair getTransferPair(Field field, BufferAllocator allocator, CallBack callBack) {
+ return new NullableStructTransferPair(this, new StructVector(field,
+ allocator,
+ callBack,
+ getConflictPolicy(),
+ allowConflictPolicyChanges), false);
+ }
+
  /**
  * {@link TransferPair} for this (nullable) {@link StructVector}.
  */

java/vector/src/test/java/org/apache/arrow/vector/TestMapVector.java

@@ -1155,4 +1155,27 @@ public void testGetTransferPairWithField() {
  toVector.clear();
  }
  }
+
+ @Test
+ public void testGetTransferPairWithFieldAndCallBack() {
+ SchemaChangeCallBack callBack = new SchemaChangeCallBack();
+ try (MapVector mapVector = MapVector.empty("mapVector", allocator, false)) {
+
+ FieldType type = new FieldType(false, ArrowType.Struct.INSTANCE, null, null);
+ AddOrGetResult<StructVector> addResult = mapVector.addOrGetVector(type);
+ FieldType keyType = new FieldType(false, MinorType.BIGINT.getType(), null, null);
+ FieldType valueType = FieldType.nullable(MinorType.FLOAT8.getType());
+ addResult.getVector().addOrGet(MapVector.KEY_NAME, keyType, BigIntVector.class);
+ addResult.getVector().addOrGet(MapVector.VALUE_NAME, valueType, Float8Vector.class);
+ mapVector.allocateNew();
+ mapVector.setValueCount(0);
+
+ assertEquals(-1, mapVector.getLastSet());
+ TransferPair tp = mapVector.getTransferPair(mapVector.getField(), allocator, callBack);
+ tp.transfer();
+ MapVector toVector = (MapVector) tp.getTo();
+ assertSame(toVector.getField(), mapVector.getField());
+ toVector.clear();
+ }
+ }
 }

java/vector/src/test/java/org/apache/arrow/vector/TestStructVector.java

@@ -307,6 +307,18 @@ public void testGetTransferPair() {
  }
  }
 
+ @Test
+ public void testGetTransferPairWithFieldAndCallBack() {
+ SchemaChangeCallBack callBack = new SchemaChangeCallBack();
+ try (final StructVector fromVector = simpleStructVector("s1", allocator)) {
+ TransferPair tp = fromVector.getTransferPair(fromVector.getField(), allocator, callBack);
+ final StructVector toVector = (StructVector) tp.getTo();
+ // Field inside a new vector created by reusing a field should be the same in memory as the original field.
+ assertSame(toVector.getField(), fromVector.getField());
+ toVector.clear();
+ }
+ }
+
  private StructVector simpleStructVector(String name, BufferAllocator allocator) {
  final String INT_COL = "struct_int_child";
  final String FLT_COL = "struct_flt_child";