Fix BLOB reading and writing.

We now correctly consider ByteBuffer, Clob, and Blob types as additional types to read and write blob data.

Closes #809

Author: mp911de

src/main/java/org/springframework/data/r2dbc/convert/MappingR2dbcConverter.java

@@ -15,6 +15,8 @@
  */
 package org.springframework.data.r2dbc.convert;
 
+import io.r2dbc.spi.Blob;
+import io.r2dbc.spi.Clob;
 import io.r2dbc.spi.ColumnMetadata;
 import io.r2dbc.spi.Row;
 import io.r2dbc.spi.RowMetadata;
@@ -167,7 +169,14 @@ private Object readFrom(Row row, @Nullable RowMetadata metadata, RelationalPersi
 
 			Object value = null;
 			if (metadata == null || RowMetadataUtils.containsColumn(metadata, identifier)) {
-				value = row.get(identifier);
+
+				if (property.getType().equals(Clob.class)) {
+					value = row.get(identifier, Clob.class);
+				} else if (property.getType().equals(Blob.class)) {
+					value = row.get(identifier, Blob.class);
+				} else {
+					value = row.get(identifier);
+				}
 			}
 
 			if (value == null) {

src/main/java/org/springframework/data/r2dbc/mapping/R2dbcSimpleTypeHolder.java

@@ -15,10 +15,13 @@
  */
 package org.springframework.data.r2dbc.mapping;
 
+import io.r2dbc.spi.Blob;
+import io.r2dbc.spi.Clob;
 import io.r2dbc.spi.Row;
 
 import java.math.BigDecimal;
 import java.math.BigInteger;
+import java.nio.ByteBuffer;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashSet;
@@ -37,8 +40,9 @@ public class R2dbcSimpleTypeHolder extends SimpleTypeHolder {
 	/**
 	 * Set of R2DBC simple types.
 	 */
-	public static final Set<Class<?>> R2DBC_SIMPLE_TYPES = Collections.unmodifiableSet(
-			new HashSet<>(Arrays.asList(OutboundRow.class, Row.class, BigInteger.class, BigDecimal.class, UUID.class)));
+	public static final Set<Class<?>> R2DBC_SIMPLE_TYPES = Collections
+			.unmodifiableSet(new HashSet<>(Arrays.asList(OutboundRow.class, Row.class, BigInteger.class, BigDecimal.class,
+					UUID.class, Blob.class, Clob.class, ByteBuffer.class)));
 
 	public static final SimpleTypeHolder HOLDER = new R2dbcSimpleTypeHolder();
 

src/test/java/org/springframework/data/r2dbc/core/PostgresIntegrationTests.java

@@ -15,9 +15,12 @@
  */
 package org.springframework.data.r2dbc.core;
 
+import static io.netty.buffer.ByteBufUtil.*;
 import static org.assertj.core.api.Assertions.*;
 import static org.springframework.data.relational.core.query.Criteria.*;
 
+import io.netty.buffer.ByteBufUtil;
+import io.netty.buffer.Unpooled;
 import io.r2dbc.postgresql.PostgresqlConnectionConfiguration;
 import io.r2dbc.postgresql.PostgresqlConnectionFactory;
 import io.r2dbc.postgresql.codec.Box;
@@ -30,23 +33,28 @@
 import io.r2dbc.postgresql.codec.Point;
 import io.r2dbc.postgresql.codec.Polygon;
 import io.r2dbc.postgresql.extension.CodecRegistrar;
+import io.r2dbc.spi.Blob;
 import io.r2dbc.spi.ConnectionFactory;
 import lombok.AllArgsConstructor;
 import lombok.Data;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
 import reactor.test.StepVerifier;
 
+import java.nio.ByteBuffer;
+import java.nio.charset.StandardCharsets;
 import java.time.Duration;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
+import java.util.concurrent.CompletableFuture;
 import java.util.function.Consumer;
 
 import javax.sql.DataSource;
 
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.RegisterExtension;
-
 import org.springframework.dao.DataAccessException;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.r2dbc.convert.EnumWriteSupport;
@@ -82,6 +90,13 @@ void before() {
 				+ "primitive_array INT[]," //
 				+ "multidimensional_array INT[]," //
 				+ "collection_array INT[][])");
+
+		template.execute("DROP TABLE IF EXISTS with_blobs");
+		template.execute("CREATE TABLE with_blobs (" //
+				+ "id serial PRIMARY KEY," //
+				+ "byte_array bytea," //
+				+ "byte_buffer bytea," //
+				+ "byte_blob bytea)");
 	}
 
 	@Test // gh-30
@@ -255,9 +270,9 @@ void shouldReadAndWriteInterval() {
 
 		template.execute("DROP TABLE IF EXISTS with_interval");
 		template.execute("CREATE TABLE with_interval (" //
-						 + "id serial PRIMARY KEY," //
-						 + "interval INTERVAL" //
-						 + ")");
+				+ "id serial PRIMARY KEY," //
+				+ "interval INTERVAL" //
+				+ ")");
 
 		R2dbcEntityTemplate template = new R2dbcEntityTemplate(client,
 				new DefaultReactiveDataAccessStrategy(PostgresDialect.INSTANCE));
@@ -289,6 +304,62 @@ private void selectAndAssert(Consumer<? super EntityWithArrays> assertion) {
 				.consumeNextWith(assertion).verifyComplete();
 	}
 
+	@Test // gh-1408
+	void shouldReadAndWriteBlobs() {
+
+		R2dbcEntityTemplate template = new R2dbcEntityTemplate(client,
+				new DefaultReactiveDataAccessStrategy(PostgresDialect.INSTANCE));
+
+		WithBlobs withBlobs = new WithBlobs();
+		byte[] content = "123ä".getBytes(StandardCharsets.UTF_8);
+
+		withBlobs.byteArray = content;
+		withBlobs.byteBuffer = ByteBuffer.wrap(content);
+		withBlobs.byteBlob = Blob.from(Mono.just(ByteBuffer.wrap(content)));
+
+		template.insert(withBlobs) //
+				.as(StepVerifier::create) //
+				.expectNextCount(1) //
+				.verifyComplete();
+
+		template.selectOne(Query.empty(), WithBlobs.class) //
+				.flatMap(it -> {
+					return Flux.from(it.byteBlob.stream()).last().map(blob -> {
+						it.byteBlob = Blob.from(Mono.just(blob));
+						return it;
+					});
+				}).as(StepVerifier::create) //
+				.consumeNextWith(actual -> {
+
+					CompletableFuture<byte[]> cf = Mono.from(actual.byteBlob.stream()).map(Unpooled::wrappedBuffer)
+							.map(ByteBufUtil::getBytes).toFuture();
+					assertThat(actual.getByteArray()).isEqualTo(content);
+					assertThat(getBytes(Unpooled.wrappedBuffer(actual.getByteBuffer()))).isEqualTo(content);
+					assertThat(cf.join()).isEqualTo(content);
+				}).verifyComplete();
+
+		template.selectOne(Query.empty(), WithBlobs.class)
+				.doOnNext(it -> it.byteArray = "foo".getBytes(StandardCharsets.UTF_8)).flatMap(template::update) //
+				.as(StepVerifier::create) //
+				.expectNextCount(1).verifyComplete();
+
+		template.selectOne(Query.empty(), WithBlobs.class) //
+				.flatMap(it -> {
+					return Flux.from(it.byteBlob.stream()).last().map(blob -> {
+						it.byteBlob = Blob.from(Mono.just(blob));
+						return it;
+					});
+				}).as(StepVerifier::create) //
+				.consumeNextWith(actual -> {
+
+					CompletableFuture<byte[]> cf = Mono.from(actual.byteBlob.stream()).map(Unpooled::wrappedBuffer)
+							.map(ByteBufUtil::getBytes).toFuture();
+					assertThat(actual.getByteArray()).isEqualTo("foo".getBytes(StandardCharsets.UTF_8));
+					assertThat(getBytes(Unpooled.wrappedBuffer(actual.getByteBuffer()))).isEqualTo(content);
+					assertThat(cf.join()).isEqualTo(content);
+				}).verifyComplete();
+	}
+
 	@Data
 	@AllArgsConstructor
 	static class EntityWithEnum {
@@ -336,4 +407,16 @@ static class EntityWithInterval {
 
 	}
 
+	@Data
+	@Table("with_blobs")
+	static class WithBlobs {
+
+		@Id Integer id;
+
+		byte[] byteArray;
+		ByteBuffer byteBuffer;
+		Blob byteBlob;
+
+	}
+
 }