Improve usage of ByteArrayOutputStream/ByteArrayInputStream

Closes gh-24805

spring-context/src/main/java/org/springframework/cache/concurrent/ConcurrentMapCache.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2020 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -202,15 +202,10 @@ public class ConcurrentMapCache extends AbstractValueAdaptingCache {
 		}
 	}
 
-	private Object serializeValue(SerializationDelegate serialization, Object storeValue) throws IOException {
+	private static Object serializeValue(SerializationDelegate serialization, Object storeValue) throws IOException {
 		ByteArrayOutputStream out = new ByteArrayOutputStream();
-		try {
-			serialization.serialize(storeValue, out);
-			return out.toByteArray();
-		}
-		finally {
-			out.close();
-		}
+		serialization.serialize(storeValue, out);
+		return out.toByteArray();
 	}
 
 	@Override
@@ -229,14 +224,9 @@ public class ConcurrentMapCache extends AbstractValueAdaptingCache {
 
 	}
 
-	private Object deserializeValue(SerializationDelegate serialization, Object storeValue) throws IOException {
+	private static Object deserializeValue(SerializationDelegate serialization, Object storeValue) throws IOException {
 		ByteArrayInputStream in = new ByteArrayInputStream((byte[]) storeValue);
-		try {
-			return serialization.deserialize(in);
-		}
-		finally {
-			in.close();
-		}
+		return serialization.deserialize(in);
 	}
 
 }

spring-core/src/main/java/org/springframework/util/StreamUtils.java

@@ -25,6 +25,7 @@ import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.OutputStream;
 import java.io.OutputStreamWriter;
+import java.io.UnsupportedEncodingException;
 import java.io.Writer;
 import java.nio.charset.Charset;
 
@@ -238,6 +239,24 @@ public abstract class StreamUtils {
 		return new NonClosingOutputStream(out);
 	}
 
+	/**
+	 * More effective equivalent of {@code new String(baos.toByteArray(), charset)}
+	 * As far as at invocation point {@code charset} is already available,
+	 * no exception is expected to be thrown.
+	 *
+	 * @param baos    {@link ByteArrayOutputStream} to be flushed into String
+	 * @param charset applicable {@link Charset}
+	 * @return String represenation of bytes stored in {@code baos}
+	 */
+	public static String baosToString(ByteArrayOutputStream baos, Charset charset) {
+		Assert.notNull(baos, "No ByteArrayOutputStream specified");
+		Assert.notNull(charset, "No Charset specified");
+		try {
+			return baos.toString(charset.name());
+		} catch (UnsupportedEncodingException e) {
+			throw new RuntimeException(e);
+		}
+	}
 
 	private static class NonClosingInputStream extends FilterInputStream {
 

spring-core/src/main/java/org/springframework/util/StringUtils.java

@@ -774,7 +774,7 @@ public abstract class StringUtils {
 				bos.write(ch);
 			}
 		}
-		return (changed ? new String(bos.toByteArray(), charset) : source);
+		return changed ? StreamUtils.baosToString(bos, charset) : source;
 	}
 
 	/**

spring-core/src/testFixtures/java/org/springframework/core/testfixture/io/SerializationTestUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2020 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -55,7 +55,6 @@ public class SerializationTestUtils {
 			oos.writeObject(o);
 			oos.flush();
 		}
-		baos.flush();
 		byte[] bytes = baos.toByteArray();
 
 		ByteArrayInputStream is = new ByteArrayInputStream(bytes);

spring-messaging/src/main/java/org/springframework/messaging/simp/stomp/StompDecoder.java

@@ -33,6 +33,7 @@ import org.springframework.messaging.support.MessageHeaderInitializer;
 import org.springframework.messaging.support.NativeMessageHeaderAccessor;
 import org.springframework.util.InvalidMimeTypeException;
 import org.springframework.util.MultiValueMap;
+import org.springframework.util.StreamUtils;
 
 /**
  * Decodes one or more STOMP frames contained in a {@link ByteBuffer}.
@@ -216,7 +217,7 @@ public class StompDecoder {
 		while (byteBuffer.remaining() > 0 && !tryConsumeEndOfLine(byteBuffer)) {
 			command.write(byteBuffer.get());
 		}
-		return new String(command.toByteArray(), StandardCharsets.UTF_8);
+		return StreamUtils.baosToString(command, StandardCharsets.UTF_8);
 	}
 
 	private void readHeaders(ByteBuffer byteBuffer, StompHeaderAccessor headerAccessor) {
@@ -231,7 +232,7 @@ public class StompDecoder {
 				headerStream.write(byteBuffer.get());
 			}
 			if (headerStream.size() > 0 && headerComplete) {
-				String header = new String(headerStream.toByteArray(), StandardCharsets.UTF_8);
+				String header = StreamUtils.baosToString(headerStream, StandardCharsets.UTF_8);
 				int colonIndex = header.indexOf(':');
 				if (colonIndex <= 0) {
 					if (byteBuffer.remaining() > 0) {

spring-test/src/main/java/org/springframework/mock/http/MockHttpOutputMessage.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2020 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -24,6 +24,7 @@ import java.nio.charset.StandardCharsets;
 
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpOutputMessage;
+import org.springframework.util.StreamUtils;
 
 /**
  * Mock implementation of {@link HttpOutputMessage}.
@@ -75,8 +76,7 @@ public class MockHttpOutputMessage implements HttpOutputMessage {
 	 * @param charset the charset to use to turn the body content to a String
 	 */
 	public String getBodyAsString(Charset charset) {
-		byte[] bytes = getBodyAsBytes();
-		return new String(bytes, charset);
+		return StreamUtils.baosToString(this.body, charset);
 	}
 
 }

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2020 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -27,6 +27,7 @@ import java.util.List;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.ObjectUtils;
+import org.springframework.util.StreamUtils;
 
 import static java.nio.charset.StandardCharsets.ISO_8859_1;
 import static java.nio.charset.StandardCharsets.UTF_8;
@@ -419,7 +420,7 @@ public final class ContentDisposition {
 				throw new IllegalArgumentException(INVALID_HEADER_FIELD_PARAMETER_FORMAT);
 			}
 		}
-		return new String(bos.toByteArray(), charset);
+		return StreamUtils.baosToString(bos, charset);
 	}
 
 	private static boolean isRFC5987AttrChar(byte c) {

spring-web/src/main/java/org/springframework/web/util/HierarchicalUriComponents.java

@@ -36,6 +36,7 @@ import org.springframework.util.CollectionUtils;
 import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.util.MultiValueMap;
 import org.springframework.util.ObjectUtils;
+import org.springframework.util.StreamUtils;
 import org.springframework.util.StringUtils;
 
 /**
@@ -359,7 +360,7 @@ final class HierarchicalUriComponents extends UriComponents {
 				bos.write(hex2);
 			}
 		}
-		return new String(bos.toByteArray(), charset);
+		return StreamUtils.baosToString(bos, charset);
 	}
 
 	private Type getHostType() {

spring-websocket/src/main/java/org/springframework/web/socket/sockjs/client/JettyXhrTransport.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2020 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -35,6 +35,7 @@ import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
+import org.springframework.util.StreamUtils;
 import org.springframework.util.concurrent.SettableListenableFuture;
 import org.springframework.web.client.HttpServerErrorException;
 import org.springframework.web.socket.CloseStatus;
@@ -247,14 +248,13 @@ public class JettyXhrTransport extends AbstractXhrTransport implements Lifecycle
 		}
 
 		private void handleFrame() {
-			byte[] bytes = this.outputStream.toByteArray();
+			String content = StreamUtils.baosToString(this.outputStream, SockJsFrame.CHARSET);
 			this.outputStream.reset();
-			String content = new String(bytes, SockJsFrame.CHARSET);
 			if (logger.isTraceEnabled()) {
 				logger.trace("XHR content received: " + content);
 			}
 			if (!PRELUDE.equals(content)) {
-				this.sockJsSession.handleFrame(new String(bytes, SockJsFrame.CHARSET));
+				this.sockJsSession.handleFrame(content);
 			}
 		}
 

spring-websocket/src/main/java/org/springframework/web/socket/sockjs/client/UndertowXhrTransport.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2020 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -38,6 +38,7 @@ import io.undertow.util.HeaderMap;
 import io.undertow.util.HttpString;
 import io.undertow.util.Methods;
 import io.undertow.util.StringReadChannelListener;
+import org.springframework.util.StreamUtils;
 import org.xnio.ChannelListener;
 import org.xnio.ChannelListeners;
 import org.xnio.IoUtils;
@@ -405,8 +406,7 @@ public class UndertowXhrTransport extends AbstractXhrTransport {
 				throw new SockJsException("Session closed.", this.session.getId(), null);
 			}
 
-			PooledByteBuffer pooled = bufferPool.allocate();
-			try {
+			try (PooledByteBuffer pooled = bufferPool.allocate()) {
 				int r;
 				do {
 					ByteBuffer buffer = pooled.getBuffer();
@@ -436,20 +436,16 @@ public class UndertowXhrTransport extends AbstractXhrTransport {
 			catch (IOException exc) {
 				onFailure(exc);
 			}
-			finally {
-				pooled.close();
-			}
 		}
 
 		private void handleFrame() {
-			byte[] bytes = this.outputStream.toByteArray();
+			String content = StreamUtils.baosToString(this.outputStream, SockJsFrame.CHARSET);
 			this.outputStream.reset();
-			String content = new String(bytes, SockJsFrame.CHARSET);
 			if (logger.isTraceEnabled()) {
 				logger.trace("XHR content received: " + content);
 			}
 			if (!PRELUDE.equals(content)) {
-				this.session.handleFrame(new String(bytes, SockJsFrame.CHARSET));
+				this.session.handleFrame(content);
 			}
 		}