Flink: Add null check to writers to prevent resurrecting null values

data/src/test/java/org/apache/iceberg/data/DataTest.java

@@ -27,10 +27,12 @@
 import java.math.BigDecimal;
 import java.nio.ByteBuffer;
 import java.nio.file.Path;
+import java.util.List;
 import java.util.UUID;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.stream.Stream;
 import org.apache.iceberg.Schema;
+import org.apache.iceberg.relocated.com.google.common.collect.ImmutableList;
 import org.apache.iceberg.types.Type;
 import org.apache.iceberg.types.TypeUtil;
 import org.apache.iceberg.types.Types;
@@ -50,6 +52,8 @@ public abstract class DataTest {
 
   protected abstract void writeAndValidate(Schema schema) throws IOException;
 
+  protected abstract void writeAndValidate(Schema schema, List<Record> data) throws IOException;
+
   protected void writeAndValidate(Schema writeSchema, Schema expectedSchema) throws IOException {
     throw new UnsupportedEncodingException(
         "Cannot run test, writeAndValidate(Schema, Schema) is not implemented");
@@ -486,4 +490,22 @@ public void testPrimitiveTypeDefaultValues(Type.PrimitiveType type, Object defau
 
     writeAndValidate(writeSchema, readSchema);
   }
+
+  @Test
+  public void testWriteNullValueForRequiredType() {
+    Assumptions.assumeThat(supportsDefaultValues()).isTrue();
+
+    Schema schema =
+        new Schema(
+            required(0, "id", LongType.get()), required(1, "string", Types.StringType.get()));
+
+    GenericRecord genericRecord = GenericRecord.create(schema);
+    genericRecord.set(0, 42L);
+    genericRecord.set(1, null);
+
+    assertThatThrownBy(
+        // The actual exception depends on the implementation, e.g.
+        // NullPointerException or IllegalArgumentException.
+        () -> writeAndValidate(schema, ImmutableList.of(genericRecord)));
+  }
 }

data/src/test/java/org/apache/iceberg/data/avro/TestGenericData.java

@@ -35,14 +35,26 @@
 import org.apache.iceberg.relocated.com.google.common.collect.Lists;
 
 public class TestGenericData extends DataTest {
+
   @Override
   protected void writeAndValidate(Schema schema) throws IOException {
     writeAndValidate(schema, schema);
   }
 
+  @Override
+  protected void writeAndValidate(Schema writeSchema, List<Record> expectedData)
+      throws IOException {
+    writeAndValidate(writeSchema, writeSchema, expectedData);
+  }
+
   @Override
   protected void writeAndValidate(Schema writeSchema, Schema expectedSchema) throws IOException {
-    List<Record> expected = RandomGenericData.generate(writeSchema, 100, 0L);
+    List<Record> data = RandomGenericData.generate(writeSchema, 100, 0L);
+    writeAndValidate(writeSchema, expectedSchema, data);
+  }
+
+  private void writeAndValidate(Schema writeSchema, Schema expectedSchema, List<Record> expected)
+      throws IOException {
 
     File testFile = File.createTempFile("junit", null, temp.toFile());
     assertThat(testFile.delete()).isTrue();

data/src/test/java/org/apache/iceberg/data/orc/TestGenericData.java

@@ -61,6 +61,11 @@ protected void writeAndValidate(Schema schema) throws IOException {
     writeAndValidateRecords(schema, expected);
   }
 
+  @Override
+  protected void writeAndValidate(Schema schema, List<Record> expectedData) throws IOException {
+    writeAndValidateRecords(schema, expectedData);
+  }
+
   @Test
   public void writeAndValidateRepeatingRecords() throws IOException {
     Schema structSchema =

data/src/test/java/org/apache/iceberg/data/parquet/TestGenericData.java

@@ -46,14 +46,25 @@
 import org.junit.jupiter.api.Test;
 
 public class TestGenericData extends DataTest {
+
   @Override
   protected void writeAndValidate(Schema schema) throws IOException {
     writeAndValidate(schema, schema);
   }
 
+  @Override
+  protected void writeAndValidate(Schema schema, List<Record> expected) throws IOException {
+    writeAndValidate(schema, schema, expected);
+  }
+
   @Override
   protected void writeAndValidate(Schema writeSchema, Schema expectedSchema) throws IOException {
-    List<Record> expected = RandomGenericData.generate(writeSchema, 100, 12228L);
+    List<Record> data = RandomGenericData.generate(writeSchema, 100, 12228L);
+    writeAndValidate(writeSchema, expectedSchema, data);
+  }
+
+  private void writeAndValidate(Schema writeSchema, Schema expectedSchema, List<Record> expected)
+      throws IOException {
 
     File testFile = File.createTempFile("junit", null, temp.toFile());
     assertThat(testFile.delete()).isTrue();

data/src/test/java/org/apache/iceberg/data/parquet/TestParquetEncryptionWithWriteSupport.java

@@ -59,6 +59,11 @@ public class TestParquetEncryptionWithWriteSupport extends DataTest {
   @Override
   protected void writeAndValidate(Schema schema) throws IOException {
     List<Record> expected = RandomGenericData.generate(schema, 100, 0L);
+    writeAndValidate(schema, expected);
+  }
+
+  @Override
+  protected void writeAndValidate(Schema schema, List<Record> expected) throws IOException {
 
     File testFile = File.createTempFile("junit", null, temp.toFile());
     assertThat(testFile.delete()).isTrue();

flink/v1.18/flink/src/main/java/org/apache/iceberg/flink/FlinkRowData.java

@@ -0,0 +1,42 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.iceberg.flink;
+
+import org.apache.flink.table.data.RowData;
+import org.apache.flink.table.types.logical.LogicalType;
+
+public class FlinkRowData {
+
+  private FlinkRowData() {}
+
+  public static RowData.FieldGetter createFieldGetter(LogicalType fieldType, int fieldPos) {
+    RowData.FieldGetter flinkFieldGetter = RowData.createFieldGetter(fieldType, fieldPos);
+    return rowData -> {
+      // Be sure to check for null values, even if the field is required. Flink
+      // RowData.createFieldGetter(..) does not null-check optional / nullable types. Without this
+      // explicit null check, the null flag of BinaryRowData will be ignored and random bytes will
+      // be parsed as actual values. This will produce incorrect writes instead of failing with a
+      // NullPointerException.
+      if (!fieldType.isNullable() && rowData.isNullAt(fieldPos)) {
+        return null;
+      }
+      return flinkFieldGetter.getFieldOrNull(rowData);
+    };
+  }
+}

flink/v1.18/flink/src/main/java/org/apache/iceberg/flink/RowDataWrapper.java

@@ -70,7 +70,7 @@ public <T> T get(int pos, Class<T> javaClass) {
       return javaClass.cast(getters[pos].get(rowData, pos));
     }
 
-    Object value = RowData.createFieldGetter(types[pos], pos).getFieldOrNull(rowData);
+    Object value = FlinkRowData.createFieldGetter(types[pos], pos).getFieldOrNull(rowData);
     return javaClass.cast(value);
   }
 

flink/v1.18/flink/src/main/java/org/apache/iceberg/flink/data/FlinkOrcWriters.java

@@ -32,6 +32,7 @@
 import org.apache.flink.table.types.logical.LogicalType;
 import org.apache.iceberg.FieldMetrics;
 import org.apache.iceberg.data.orc.GenericOrcWriters;
+import org.apache.iceberg.flink.FlinkRowData;
 import org.apache.iceberg.orc.OrcValueWriter;
 import org.apache.iceberg.relocated.com.google.common.base.Preconditions;
 import org.apache.iceberg.relocated.com.google.common.collect.Lists;
@@ -298,7 +299,7 @@ static class RowDataWriter extends GenericOrcWriters.StructWriter<RowData> {
 
       this.fieldGetters = Lists.newArrayListWithExpectedSize(types.size());
       for (int i = 0; i < types.size(); i++) {
-        fieldGetters.add(RowData.createFieldGetter(types.get(i), i));
+        fieldGetters.add(FlinkRowData.createFieldGetter(types.get(i), i));
       }
     }
 

flink/v1.18/flink/src/main/java/org/apache/iceberg/flink/data/FlinkParquetWriters.java

@@ -35,6 +35,7 @@
 import org.apache.flink.table.types.logical.RowType.RowField;
 import org.apache.flink.table.types.logical.SmallIntType;
 import org.apache.flink.table.types.logical.TinyIntType;
+import org.apache.iceberg.flink.FlinkRowData;
 import org.apache.iceberg.parquet.ParquetValueReaders;
 import org.apache.iceberg.parquet.ParquetValueWriter;
 import org.apache.iceberg.parquet.ParquetValueWriters;
@@ -492,7 +493,7 @@ private static class RowDataWriter extends ParquetValueWriters.StructWriter<RowD
       super(writers);
       fieldGetter = new RowData.FieldGetter[types.size()];
       for (int i = 0; i < types.size(); i += 1) {
-        fieldGetter[i] = RowData.createFieldGetter(types.get(i), i);
+        fieldGetter[i] = FlinkRowData.createFieldGetter(types.get(i), i);
       }
     }
 

flink/v1.18/flink/src/main/java/org/apache/iceberg/flink/data/FlinkValueWriters.java

@@ -31,6 +31,7 @@
 import org.apache.flink.table.data.TimestampData;
 import org.apache.flink.table.types.logical.LogicalType;
 import org.apache.iceberg.avro.ValueWriter;
+import org.apache.iceberg.flink.FlinkRowData;
 import org.apache.iceberg.types.TypeUtil;
 import org.apache.iceberg.util.DecimalUtil;
 
@@ -229,7 +230,7 @@ private RowWriter(List<ValueWriter<?>> writers, List<LogicalType> types) {
       this.getters = new RowData.FieldGetter[writers.size()];
       for (int i = 0; i < writers.size(); i += 1) {
         this.writers[i] = writers.get(i);
-        this.getters[i] = RowData.createFieldGetter(types.get(i), i);
+        this.getters[i] = FlinkRowData.createFieldGetter(types.get(i), i);
       }
     }
 

flink/v1.18/flink/src/main/java/org/apache/iceberg/flink/data/RowDataProjection.java

@@ -32,6 +32,7 @@
 import org.apache.flink.types.RowKind;
 import org.apache.flink.util.StringUtils;
 import org.apache.iceberg.Schema;
+import org.apache.iceberg.flink.FlinkRowData;
 import org.apache.iceberg.flink.FlinkSchemaUtil;
 import org.apache.iceberg.relocated.com.google.common.base.Preconditions;
 import org.apache.iceberg.relocated.com.google.common.collect.Maps;
@@ -135,7 +136,7 @@ private static RowData.FieldGetter createFieldGetter(
             projectField,
             rowField);
 
-        return RowData.createFieldGetter(rowType.getTypeAt(position), position);
+        return FlinkRowData.createFieldGetter(rowType.getTypeAt(position), position);
 
       case LIST:
         Types.ListType projectedList = projectField.type().asListType();
@@ -150,10 +151,10 @@ private static RowData.FieldGetter createFieldGetter(
             projectField,
             rowField);
 
-        return RowData.createFieldGetter(rowType.getTypeAt(position), position);
+        return FlinkRowData.createFieldGetter(rowType.getTypeAt(position), position);
 
       default:
-        return RowData.createFieldGetter(rowType.getTypeAt(position), position);
+        return FlinkRowData.createFieldGetter(rowType.getTypeAt(position), position);
     }
   }
 

flink/v1.18/flink/src/main/java/org/apache/iceberg/flink/source/reader/RowDataRecordFactory.java

@@ -23,6 +23,7 @@
 import org.apache.flink.table.data.RowData;
 import org.apache.flink.table.runtime.typeutils.InternalSerializers;
 import org.apache.flink.table.types.logical.RowType;
+import org.apache.iceberg.flink.FlinkRowData;
 import org.apache.iceberg.flink.data.RowDataUtil;
 
 class RowDataRecordFactory implements RecordFactory<RowData> {
@@ -45,7 +46,7 @@ static TypeSerializer[] createFieldSerializers(RowType rowType) {
   static RowData.FieldGetter[] createFieldGetters(RowType rowType) {
     RowData.FieldGetter[] fieldGetters = new RowData.FieldGetter[rowType.getFieldCount()];
     for (int i = 0; i < rowType.getFieldCount(); ++i) {
-      fieldGetters[i] = RowData.createFieldGetter(rowType.getTypeAt(i), i);
+      fieldGetters[i] = FlinkRowData.createFieldGetter(rowType.getTypeAt(i), i);
     }
 
     return fieldGetters;

flink/v1.18/flink/src/test/java/org/apache/iceberg/flink/TestHelpers.java

@@ -89,7 +89,7 @@ public static RowData copyRowData(RowData from, RowType rowType) {
             .toArray(TypeSerializer[]::new);
     RowData.FieldGetter[] fieldGetters = new RowData.FieldGetter[rowType.getFieldCount()];
     for (int i = 0; i < rowType.getFieldCount(); ++i) {
-      fieldGetters[i] = RowData.createFieldGetter(rowType.getTypeAt(i), i);
+      fieldGetters[i] = FlinkRowData.createFieldGetter(rowType.getTypeAt(i), i);
     }
 
     return RowDataUtil.clone(from, null, rowType, fieldSerializers, fieldGetters);
@@ -200,7 +200,7 @@ public static void assertRowData(
       Object actual =
           actualRowData.isNullAt(i)
               ? null
-              : RowData.createFieldGetter(logicalType, i).getFieldOrNull(actualRowData);
+              : FlinkRowData.createFieldGetter(logicalType, i).getFieldOrNull(actualRowData);
       assertEquals(types.get(i), logicalType, expected, actual);
     }
   }

flink/v1.18/flink/src/test/java/org/apache/iceberg/flink/data/AbstractTestFlinkAvroReaderWriter.java

@@ -67,13 +67,13 @@ public abstract class AbstractTestFlinkAvroReaderWriter extends DataTest {
   @Override
   protected void writeAndValidate(Schema schema) throws IOException {
     List<Record> expectedRecords = RandomGenericData.generate(schema, NUM_RECORDS, 1991L);
-    writeAndValidate(schema, expectedRecords, NUM_RECORDS);
+    writeAndValidate(schema, expectedRecords);
   }
 
   protected abstract Avro.ReadBuilder createAvroReadBuilder(File recordsFile, Schema schema);
 
-  private void writeAndValidate(Schema schema, List<Record> expectedRecords, int numRecord)
-      throws IOException {
+  @Override
+  protected void writeAndValidate(Schema schema, List<Record> expectedRecords) throws IOException {
     RowType flinkSchema = FlinkSchemaUtil.convert(schema);
     List<RowData> expectedRows = Lists.newArrayList(RandomRowData.convert(schema, expectedRecords));
 
@@ -93,7 +93,7 @@ private void writeAndValidate(Schema schema, List<Record> expectedRecords, int n
     try (CloseableIterable<RowData> reader = createAvroReadBuilder(recordsFile, schema).build()) {
       Iterator<Record> expected = expectedRecords.iterator();
       Iterator<RowData> rows = reader.iterator();
-      for (int i = 0; i < numRecord; i++) {
+      for (int i = 0; i < expectedRecords.size(); i++) {
         assertThat(rows).hasNext();
         TestHelpers.assertRowData(schema.asStruct(), flinkSchema, expected.next(), rows.next());
       }
@@ -120,7 +120,7 @@ private void writeAndValidate(Schema schema, List<Record> expectedRecords, int n
             .build()) {
       Iterator<RowData> expected = expectedRows.iterator();
       Iterator<Record> records = reader.iterator();
-      for (int i = 0; i < numRecord; i += 1) {
+      for (int i = 0; i < expectedRecords.size(); i += 1) {
         assertThat(records).hasNext();
         TestHelpers.assertRowData(schema.asStruct(), flinkSchema, records.next(), expected.next());
       }
@@ -177,6 +177,6 @@ public void testNumericTypes() throws IOException {
                 1643811742000L,
                 10.24d));
 
-    writeAndValidate(SCHEMA_NUM_TYPE, expected, 2);
+    writeAndValidate(SCHEMA_NUM_TYPE, expected);
   }
 }

flink/v1.18/flink/src/test/java/org/apache/iceberg/flink/data/TestFlinkOrcReaderWriter.java

@@ -45,8 +45,13 @@ public class TestFlinkOrcReaderWriter extends DataTest {
 
   @Override
   protected void writeAndValidate(Schema schema) throws IOException {
-    RowType flinkSchema = FlinkSchemaUtil.convert(schema);
     List<Record> expectedRecords = RandomGenericData.generate(schema, NUM_RECORDS, 1990L);
+    writeAndValidate(schema, expectedRecords);
+  }
+
+  @Override
+  protected void writeAndValidate(Schema schema, List<Record> expectedRecords) throws IOException {
+    RowType flinkSchema = FlinkSchemaUtil.convert(schema);
     List<RowData> expectedRows = Lists.newArrayList(RandomRowData.convert(schema, expectedRecords));
 
     File recordsFile = File.createTempFile("junit", null, temp.toFile());

flink/v1.18/flink/src/test/java/org/apache/iceberg/flink/data/TestFlinkParquetReader.java

@@ -250,4 +250,9 @@ protected void writeAndValidate(Schema schema) throws IOException {
   protected void writeAndValidate(Schema writeSchema, Schema expectedSchema) throws IOException {
     writeAndValidate(RandomGenericData.generate(writeSchema, 100, 0L), writeSchema, expectedSchema);
   }
+
+  @Override
+  protected void writeAndValidate(Schema schema, List<Record> expectedData) throws IOException {
+    writeAndValidate(expectedData, schema, schema);
+  }
 }