Revised ResizableByteArrayOutputStream as an actual subclass of ByteArrayOutputStream, and consistently applied appropriate ByteArrayOutputStream initial capacities across the codebase

Issue: SPR-11594

Author: jhoeller

spring-core/src/main/java/org/springframework/core/convert/support/PropertiesToStringConverter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2014 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.
@@ -34,7 +34,7 @@ final class PropertiesToStringConverter implements Converter<Properties, String>
 	@Override
 	public String convert(Properties source) {
 		try {
-			ByteArrayOutputStream os = new ByteArrayOutputStream();
+			ByteArrayOutputStream os = new ByteArrayOutputStream(256);
 			source.store(os, null);
 			return os.toString("ISO-8859-1");
 		}

spring-core/src/main/java/org/springframework/core/serializer/support/SerializingConverter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2014 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.
@@ -57,7 +57,7 @@ public SerializingConverter(Serializer<Object> serializer) {
 	 */
 	@Override
 	public byte[] convert(Object source) {
-		ByteArrayOutputStream byteStream = new ByteArrayOutputStream(128);
+		ByteArrayOutputStream byteStream = new ByteArrayOutputStream(256);
 		try  {
 			this.serializer.serialize(source, byteStream);
 			return byteStream.toByteArray();

spring-core/src/main/java/org/springframework/core/style/ToStringCreator.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2014 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.
@@ -36,11 +36,11 @@ public class ToStringCreator {
 			new DefaultToStringStyler(StylerUtils.DEFAULT_VALUE_STYLER);
 
 
-	private StringBuilder buffer = new StringBuilder(512);
+	private final StringBuilder buffer = new StringBuilder(256);
 
-	private ToStringStyler styler;
+	private final ToStringStyler styler;
 
-	private Object object;
+	private final Object object;
 
 	private boolean styledFirstField;
 

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

@@ -13,143 +13,79 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.util;
 
-import java.io.IOException;
-import java.io.OutputStream;
+import java.io.ByteArrayOutputStream;
 
 /**
- * A variation of {@link java.io.ByteArrayOutputStream} that:
+ * An extension of {@link java.io.ByteArrayOutputStream} that:
  * <ul>
- * <li>has public {@link org.springframework.util.ResizableByteArrayOutputStream#grow(int)} and
- * {@link org.springframework.util.ResizableByteArrayOutputStream#resize(int)} methods to get more control
- * over the the size of the internal buffer</li>
- * <li>does not synchronize on buffer access - so this class should not be used if concurrent access
- * to the buffer is expected</li>
+ * <li>has public {@link org.springframework.util.ResizableByteArrayOutputStream#grow(int)}
+ * and {@link org.springframework.util.ResizableByteArrayOutputStream#resize(int)} methods
+ * to get more control over the the size of the internal buffer</li>
+ * <li>has a higher initial capacity (256) by default</li>
  * </ul>
  *
  * @author Brian Clozel
+ * @author Juergen Hoeller
  * @since 4.0
  */
-public class ResizableByteArrayOutputStream extends OutputStream {
-
-	private static final int INITIAL_BUFFER_SIZE = 32;
+public class ResizableByteArrayOutputStream extends ByteArrayOutputStream {
 
-	protected byte[] buffer;
+	private static final int DEFAULT_INITIAL_CAPACITY = 256;
 
-	protected int count;
 
 	/**
-	 * Create a new <code>ByteArrayOutputStream</code> with the default buffer size of 32 bytes.
+	 * Create a new <code>ResizableByteArrayOutputStream</code>
+	 * with the default initial capacity of 128 bytes.
 	 */
 	public ResizableByteArrayOutputStream() {
-		this(INITIAL_BUFFER_SIZE);
-	}
-
-	/**
-	 * Create a new <code>ByteArrayOutputStream</code> with a specified initial buffer size.
-	 *
-	 * @param size The initial buffer size in bytes
-	 */
-	public ResizableByteArrayOutputStream(int size) {
-		buffer = new byte[size];
-		count = 0;
-	}
-
-	/**
-	 * Return the size of the internal buffer.
-	 */
-	public int size() {
-		return buffer.length;
+		super(DEFAULT_INITIAL_CAPACITY);
 	}
 
 	/**
-	 * Return the number of bytes that have been written to the buffer so far.
+	 * Create a new <code>ResizableByteArrayOutputStream</code>
+	 * with the specified initial capacity.
+	 * @param initialCapacity the initial buffer size in bytes
 	 */
-	public int count() {
-		return count;
+	public ResizableByteArrayOutputStream(int initialCapacity) {
+		super(initialCapacity);
 	}
 
-	/**
-	 * Discard all bytes written to the internal buffer by setting the <code>count</code> variable to 0.
-	 */
-	public void reset() {
-		count = 0;
-	}
 
 	/**
-	 * Grow the internal buffer size
-	 * @param add number of bytes to add to the current buffer size
+	 * Resize the internal buffer size to a specified capacity.
+	 * @param targetCapacity the desired size of the buffer
+	 * @throws IllegalArgumentException if the given capacity is smaller than
+	 * the actual size of the content stored in the buffer already
 	 * @see ResizableByteArrayOutputStream#size()
 	 */
-	public void grow(int add) {
-		if (count + add > buffer.length) {
-			int newlen = Math.max(buffer.length * 2, count + add);
-			resize(newlen);
-		}
+	public synchronized void resize(int targetCapacity) {
+		Assert.isTrue(targetCapacity >= this.count, "New capacity must not be smaller than current size");
+		byte[] resizedBuffer = new byte[targetCapacity];
+		System.arraycopy(this.buf, 0, resizedBuffer, 0, this.count);
+		this.buf = resizedBuffer;
 	}
 
 	/**
-	 * Resize the internal buffer size to a specified value
-	 * @param size the size of the buffer
-	 * @throws java.lang.IllegalArgumentException if the given size is
-	 * smaller than the actual size of the content stored in the buffer
+	 * Grow the internal buffer size.
+	 * @param additionalCapacity the number of bytes to add to the current buffer size
 	 * @see ResizableByteArrayOutputStream#size()
 	 */
-	public void resize(int size) {
-		Assert.isTrue(size >= count);
-
-		byte[] newbuf = new byte[size];
-		System.arraycopy(buffer, 0, newbuf, 0, count);
-		buffer = newbuf;
-	}
-
-	/**
-	 * Write the specified byte into the internal buffer, thus incrementing the
-	 * {{@link org.springframework.util.ResizableByteArrayOutputStream#count()}}
-	 * @param oneByte the byte to be written in the buffer
-	 * @see ResizableByteArrayOutputStream#count()
-	 */
-	public void write(int oneByte) {
-		grow(1);
-		buffer[count++] = (byte) oneByte;
-	}
-
-	/**
-	 * Write <code>add</code> bytes from the passed in array
-	 * <code>inBuffer</code> starting at index <code>offset</code> into the
-	 * internal buffer.
-	 *
-	 * @param inBuffer The byte array to write data from
-	 * @param offset The index into the buffer to start writing data from
-	 * @param add The number of bytes to write
-	 * @see ResizableByteArrayOutputStream#count()
-	 */
-	public void write(byte[] inBuffer, int offset, int add) {
-		if (add >= 0) {
-			grow(add);
+	public synchronized void grow(int additionalCapacity) {
+		Assert.isTrue(additionalCapacity >= 0, "Additional capacity must be 0 or higher");
+		if (this.count + additionalCapacity > this.buf.length) {
+			int newCapacity = Math.max(this.buf.length * 2, this.count + additionalCapacity);
+			resize(newCapacity);
 		}
-		System.arraycopy(inBuffer, offset, buffer, count, add);
-		count += add;
-	}
-
-	/**
-	 * Write all bytes that have been written to the specified <code>OutputStream</code>.
-	 *
-	 * @param out The <code>OutputStream</code> to write to
-	 * @exception IOException If an error occurs
-	 */
-	public void writeTo(OutputStream out) throws IOException {
-		out.write(buffer, 0, count);
 	}
 
 	/**
-	 * Return a byte array containing the bytes that have been written to this stream so far.
+	 * Return the current size of this stream's internal buffer.
 	 */
-	public byte[] toByteArray() {
-		byte[] ret = new byte[count];
-		System.arraycopy(buffer, 0, ret, 0, count);
-		return ret;
+	public synchronized int capacity() {
+		return this.buf.length;
 	}
 
 }

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2010 the original author or authors.
+ * Copyright 2002-2014 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.
@@ -39,7 +39,7 @@ public static byte[] serialize(Object object) {
 		if (object == null) {
 			return null;
 		}
-		ByteArrayOutputStream baos = new ByteArrayOutputStream();
+		ByteArrayOutputStream baos = new ByteArrayOutputStream(1024);
 		try {
 			ObjectOutputStream oos = new ObjectOutputStream(baos);
 			oos.writeObject(object);

spring-core/src/test/java/org/springframework/util/ResizableByteArrayOutputStreamTests.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.util;
 
 import org.junit.Before;
@@ -22,56 +23,56 @@
 
 /**
  * @author Brian Clozel
+ * @author Juergen Hoeller
  */
 public class ResizableByteArrayOutputStreamTests {
 
-	private ResizableByteArrayOutputStream baos;
+	private static final int INITIAL_CAPACITY = 256;
 
-	private String helloString;
+	private ResizableByteArrayOutputStream baos;
 
 	private byte[] helloBytes;
 
-	private static final int INITIAL_SIZE = 32;
 
 	@Before
 	public void setUp() throws Exception {
-		this.baos = new ResizableByteArrayOutputStream(INITIAL_SIZE);
-		this.helloString = "Hello World";
-		this.helloBytes = helloString.getBytes("UTF-8");
+		this.baos = new ResizableByteArrayOutputStream(INITIAL_CAPACITY);
+		this.helloBytes = "Hello World".getBytes("UTF-8");
 	}
 
+
 	@Test
 	public void resize() throws Exception {
-		assertEquals(INITIAL_SIZE, this.baos.buffer.length);
+		assertEquals(INITIAL_CAPACITY, this.baos.capacity());
 		this.baos.write(helloBytes);
 		int size = 64;
 		this.baos.resize(size);
-		assertEquals(size, this.baos.buffer.length);
-		assertByteArrayEqualsString(helloString, this.baos);
+		assertEquals(size, this.baos.capacity());
+		assertByteArrayEqualsString(this.baos);
 	}
 
 	@Test
 	public void autoGrow() {
-		assertEquals(INITIAL_SIZE, this.baos.buffer.length);
-		for(int i= 0; i < 33; i++) {
+		assertEquals(INITIAL_CAPACITY, this.baos.capacity());
+		for(int i = 0; i < 129; i++) {
 			this.baos.write(0);
 		}
-		assertEquals(64, this.baos.buffer.length);
+		assertEquals(256, this.baos.capacity());
 	}
 
 	@Test
 	public void grow() throws Exception {
-		assertEquals(INITIAL_SIZE, this.baos.buffer.length);
+		assertEquals(INITIAL_CAPACITY, this.baos.capacity());
 		this.baos.write(helloBytes);
-		this.baos.grow(100);
-		assertEquals(this.helloString.length() + 100, this.baos.buffer.length);
-		assertByteArrayEqualsString(helloString, this.baos);
+		this.baos.grow(1000);
+		assertEquals(this.helloBytes.length + 1000, this.baos.capacity());
+		assertByteArrayEqualsString(this.baos);
 	}
 
 	@Test
 	public void write() throws Exception{
 		this.baos.write(helloBytes);
-		assertByteArrayEqualsString(helloString, this.baos);
+		assertByteArrayEqualsString(this.baos);
 	}
 
 	@Test(expected = IllegalArgumentException.class)
@@ -80,9 +81,9 @@ public void failResize() throws Exception{
 		this.baos.resize(5);
 	}
 
-	private void assertByteArrayEqualsString(String expected, ResizableByteArrayOutputStream actual) {
-		String actualString = new String(actual.buffer, 0, actual.count());
-		assertEquals(expected, actualString);
+
+	private void assertByteArrayEqualsString(ResizableByteArrayOutputStream actual) {
+		assertArrayEquals(helloBytes, actual.toByteArray());
 	}
 
 }

spring-jms/src/main/java/org/springframework/jms/support/converter/MappingJackson2MessageConverter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2014 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.
@@ -218,7 +218,7 @@ protected TextMessage mapToTextMessage(Object object, Session session, ObjectMap
 	protected BytesMessage mapToBytesMessage(Object object, Session session, ObjectMapper objectMapper)
 			throws JMSException, IOException {
 
-		ByteArrayOutputStream bos = new ByteArrayOutputStream();
+		ByteArrayOutputStream bos = new ByteArrayOutputStream(1024);
 		OutputStreamWriter writer = new OutputStreamWriter(bos, this.encoding);
 		objectMapper.writeValue(writer, object);
 

spring-jms/src/main/java/org/springframework/jms/support/converter/MappingJacksonMessageConverter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2014 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.
@@ -221,7 +221,7 @@ protected TextMessage mapToTextMessage(Object object, Session session, ObjectMap
 	protected BytesMessage mapToBytesMessage(Object object, Session session, ObjectMapper objectMapper)
 			throws JMSException, IOException {
 
-		ByteArrayOutputStream bos = new ByteArrayOutputStream();
+		ByteArrayOutputStream bos = new ByteArrayOutputStream(1024);
 		OutputStreamWriter writer = new OutputStreamWriter(bos, this.encoding);
 		objectMapper.writeValue(writer, object);
 

spring-jms/src/main/java/org/springframework/jms/support/converter/MarshallingMessageConverter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2014 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.
@@ -231,7 +231,7 @@ protected TextMessage marshalToTextMessage(Object object, Session session, Marsh
 	protected BytesMessage marshalToBytesMessage(Object object, Session session, Marshaller marshaller)
 			throws JMSException, IOException, XmlMappingException {
 
-		ByteArrayOutputStream bos = new ByteArrayOutputStream();
+		ByteArrayOutputStream bos = new ByteArrayOutputStream(1024);
 		StreamResult streamResult = new StreamResult(bos);
 		marshaller.marshal(object, streamResult);
 		BytesMessage message = session.createBytesMessage();