Polishing

spring-core/src/main/java/org/springframework/core/io/buffer/DataBufferUtils.java

@@ -139,7 +139,6 @@ public abstract class DataBufferUtils {
 		DataBuffer dataBuffer = dataBufferFactory.allocateBuffer(bufferSize);
 		ByteBuffer byteBuffer = dataBuffer.asByteBuffer(0, bufferSize);
 
-
 		Flux<DataBuffer> result = Flux.using(channelSupplier,
 				channel -> Flux.create(sink -> {
 					AsynchronousFileChannelReadCompletionHandler completionHandler =
@@ -265,7 +264,7 @@ public abstract class DataBufferUtils {
 	 * @param channel the channel to write to
 	 * @return a flux containing the same buffers as in {@code source}, that starts the writing
 	 * process when subscribed to, and that publishes any writing errors and the completion signal
-	 * @since 5.1
+	 * @since 5.0.10
 	 */
 	public static Flux<DataBuffer> write(Publisher<DataBuffer> source, AsynchronousFileChannel channel) {
 		return write(source, channel, 0);
@@ -329,7 +328,6 @@ public abstract class DataBufferUtils {
 
 		return Flux.defer(() -> {
 			AtomicLong countDown = new AtomicLong(maxByteCount);
-
 			return Flux.from(publisher)
 					.map(buffer -> {
 						long remainder = countDown.addAndGet(-buffer.readableByteCount());
@@ -359,7 +357,6 @@ public abstract class DataBufferUtils {
 
 		return Flux.defer(() -> {
 			AtomicLong countDown = new AtomicLong(maxByteCount);
-
 			return Flux.from(publisher)
 					.skipUntil(buffer -> {
 						long remainder = countDown.addAndGet(-buffer.readableByteCount());

spring-core/src/main/java/org/springframework/core/io/buffer/NettyDataBuffer.java

@@ -26,6 +26,7 @@ import io.netty.buffer.ByteBufInputStream;
 import io.netty.buffer.ByteBufOutputStream;
 
 import org.springframework.util.Assert;
+import org.springframework.util.ObjectUtils;
 
 /**
  * Implementation of the {@code DataBuffer} interface that wraps a Netty
@@ -68,7 +69,7 @@ public class NettyDataBuffer implements PooledDataBuffer {
 
 	@Override
 	public int indexOf(IntPredicate predicate, int fromIndex) {
-		Assert.notNull(predicate, "'predicate' must not be null");
+		Assert.notNull(predicate, "IntPredicate must not be null");
 		if (fromIndex < 0) {
 			fromIndex = 0;
 		}
@@ -81,7 +82,7 @@ public class NettyDataBuffer implements PooledDataBuffer {
 
 	@Override
 	public int lastIndexOf(IntPredicate predicate, int fromIndex) {
-		Assert.notNull(predicate, "'predicate' must not be null");
+		Assert.notNull(predicate, "IntPredicate must not be null");
 		if (fromIndex < 0) {
 			return -1;
 		}
@@ -174,9 +175,7 @@ public class NettyDataBuffer implements PooledDataBuffer {
 
 	@Override
 	public NettyDataBuffer write(DataBuffer... buffers) {
-		Assert.notNull(buffers, "'buffers' must not be null");
-
-		if (buffers.length > 0) {
+		if (!ObjectUtils.isEmpty(buffers)) {
 			if (hasNettyDataBuffers(buffers)) {
 				ByteBuf[] nativeBuffers = new ByteBuf[buffers.length];
 				for (int i = 0 ; i < buffers.length; i++) {
@@ -196,9 +195,9 @@ public class NettyDataBuffer implements PooledDataBuffer {
 		return this;
 	}
 
-	private static boolean hasNettyDataBuffers(DataBuffer[] dataBuffers) {
-		for (DataBuffer dataBuffer : dataBuffers) {
-			if (!(dataBuffer instanceof NettyDataBuffer)) {
+	private static boolean hasNettyDataBuffers(DataBuffer[] buffers) {
+		for (DataBuffer buffer : buffers) {
+			if (!(buffer instanceof NettyDataBuffer)) {
 				return false;
 			}
 		}
@@ -207,25 +206,25 @@ public class NettyDataBuffer implements PooledDataBuffer {
 
 	@Override
 	public NettyDataBuffer write(ByteBuffer... buffers) {
-		Assert.notNull(buffers, "'buffers' must not be null");
-
-		for (ByteBuffer buffer : buffers) {
-			this.byteBuf.writeBytes(buffer);
+		if (!ObjectUtils.isEmpty(buffers)) {
+			for (ByteBuffer buffer : buffers) {
+				this.byteBuf.writeBytes(buffer);
+			}
 		}
 		return this;
 	}
 
 	/**
-	 * Writes one or more Netty {@link ByteBuf ByteBufs} to this buffer, starting at the current
-	 * writing position.
+	 * Writes one or more Netty {@link ByteBuf ByteBufs} to this buffer,
+	 * starting at the current writing position.
 	 * @param byteBufs the buffers to write into this buffer
 	 * @return this buffer
 	 */
 	public NettyDataBuffer write(ByteBuf... byteBufs) {
-		Assert.notNull(byteBufs, "'byteBufs' must not be null");
-
-		for (ByteBuf byteBuf : byteBufs) {
-			this.byteBuf.writeBytes(byteBuf);
+		if (!ObjectUtils.isEmpty(byteBufs)) {
+			for (ByteBuf byteBuf : byteBufs) {
+				this.byteBuf.writeBytes(byteBuf);
+			}
 		}
 		return this;
 	}

spring-web/src/main/java/org/springframework/http/CacheControl.java

@@ -253,48 +253,55 @@ public class CacheControl {
 
 
 	/**
-	 * Return the "Cache-Control" header value.
-	 * @return {@code null} if no directive was added, or the header value otherwise
+	 * Return the "Cache-Control" header value, if any.
+	 * @return the header value, or {@code null} if no directive was added
 	 */
 	@Nullable
 	public String getHeaderValue() {
-		StringBuilder ccValue = new StringBuilder();
+		String headerValue = toHeaderValue();
+		return (StringUtils.hasText(headerValue) ? headerValue : null);
+	}
+
+	/**
+	 * Return the "Cache-Control" header value.
+	 * @return the header value (potentially empty)
+	 */
+	private String toHeaderValue() {
+		StringBuilder headerValue = new StringBuilder();
 		if (this.maxAge != -1) {
-			appendDirective(ccValue, "max-age=" + Long.toString(this.maxAge));
+			appendDirective(headerValue, "max-age=" + this.maxAge);
 		}
 		if (this.noCache) {
-			appendDirective(ccValue, "no-cache");
+			appendDirective(headerValue, "no-cache");
 		}
 		if (this.noStore) {
-			appendDirective(ccValue, "no-store");
+			appendDirective(headerValue, "no-store");
 		}
 		if (this.mustRevalidate) {
-			appendDirective(ccValue, "must-revalidate");
+			appendDirective(headerValue, "must-revalidate");
 		}
 		if (this.noTransform) {
-			appendDirective(ccValue, "no-transform");
+			appendDirective(headerValue, "no-transform");
 		}
 		if (this.cachePublic) {
-			appendDirective(ccValue, "public");
+			appendDirective(headerValue, "public");
 		}
 		if (this.cachePrivate) {
-			appendDirective(ccValue, "private");
+			appendDirective(headerValue, "private");
 		}
 		if (this.proxyRevalidate) {
-			appendDirective(ccValue, "proxy-revalidate");
+			appendDirective(headerValue, "proxy-revalidate");
 		}
 		if (this.sMaxAge != -1) {
-			appendDirective(ccValue, "s-maxage=" + Long.toString(this.sMaxAge));
+			appendDirective(headerValue, "s-maxage=" + this.sMaxAge);
 		}
 		if (this.staleIfError != -1) {
-			appendDirective(ccValue, "stale-if-error=" + Long.toString(this.staleIfError));
+			appendDirective(headerValue, "stale-if-error=" + this.staleIfError);
 		}
 		if (this.staleWhileRevalidate != -1) {
-			appendDirective(ccValue, "stale-while-revalidate=" + Long.toString(this.staleWhileRevalidate));
+			appendDirective(headerValue, "stale-while-revalidate=" + this.staleWhileRevalidate);
 		}
-
-		String ccHeaderValue = ccValue.toString();
-		return (StringUtils.hasText(ccHeaderValue) ? ccHeaderValue : null);
+		return headerValue.toString();
 	}
 
 	private void appendDirective(StringBuilder builder, String value) {
@@ -304,8 +311,10 @@ public class CacheControl {
 		builder.append(value);
 	}
 
+
 	@Override
 	public String toString() {
-		return "CacheControl [" + getHeaderValue() + "]";
+		return "CacheControl [" + toHeaderValue() + "]";
 	}
+
 }