Refactor common code, Javadoc, reuse constants, use 120 max line length.

Javadoc: Sentences end in a period.

Author: Gary Gregory

src/main/java/org/apache/commons/io/filefilter/IOFileFilter.java

@@ -43,8 +43,8 @@ public interface IOFileFilter extends FileFilter, FilenameFilter, PathFilter {
      * Defined in {@link java.io.FileFilter}.
      * </p>
      *
-     * @param file the File to check
-     * @return true if this file matches the test
+     * @param file the File to check.
+     * @return true if this file matches the test.
      */
     @Override
     boolean accept(File file);
@@ -55,18 +55,18 @@ public interface IOFileFilter extends FileFilter, FilenameFilter, PathFilter {
      * Defined in {@link java.io.FilenameFilter}.
      * </p>
      *
-     * @param dir the directory File to check
-     * @param name the file name within the directory to check
-     * @return true if this file matches the test
+     * @param dir the directory File to check.
+     * @param name the file name within the directory to check.
+     * @return true if this file matches the test.
      */
     @Override
     boolean accept(File dir, String name);
 
     /**
      * Checks to see if the Path should be accepted by this filter.
      *
-     * @param path the Path to check
-     * @return true if this path matches the test
+     * @param path the Path to check.
+     * @return true if this path matches the test.
      * @since 2.9.0
      */
     @Override
@@ -78,7 +78,7 @@ default FileVisitResult accept(final Path path, final BasicFileAttributes attrib
      * Creates a new "and" filter with this filter.
      *
      * @param fileFilter the filter to "and".
-     * @return a new filter
+     * @return a new filter.
      * @since 2.9.0
      */
     default IOFileFilter and(final IOFileFilter fileFilter) {
@@ -88,7 +88,7 @@ default IOFileFilter and(final IOFileFilter fileFilter) {
     /**
      * Creates a new "not" filter with this filter.
      *
-     * @return a new filter
+     * @return a new filter.
      * @since 2.9.0
      */
     default IOFileFilter negate() {
@@ -99,7 +99,7 @@ default IOFileFilter negate() {
      * Creates a new "or" filter with this filter.
      *
      * @param fileFilter the filter to "or".
-     * @return a new filter
+     * @return a new filter.
      * @since 2.9.0
      */
     default IOFileFilter or(final IOFileFilter fileFilter) {

src/main/java/org/apache/commons/io/input/buffer/CircularBufferInputStream.java

@@ -16,31 +16,37 @@
  */
 package org.apache.commons.io.input.buffer;
 
+import static org.apache.commons.io.IOUtils.EOF;
+
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.Objects;
 
 import org.apache.commons.io.IOUtils;
 
-
 /**
- * Implementation of a buffered input stream, which is internally based on the
- * {@link CircularByteBuffer}. Unlike the {@link java.io.BufferedInputStream}, this one
- * doesn't need to reallocate byte arrays internally.
+ * Implements a buffered input stream, which is internally based on a {@link CircularByteBuffer}. Unlike the
+ * {@link java.io.BufferedInputStream}, this one doesn't need to reallocate byte arrays internally.
  */
 public class CircularBufferInputStream extends InputStream {
+
+    /** What we are streaming, used to fill the internal buffer. */
     protected final InputStream in;
+    
+    /** Internal buffer. */
     protected final CircularByteBuffer buffer;
+
+    /** Internal buffer size. */
     protected final int bufferSize;
-    private boolean eofSeen;
+    
+    /** Whether we've see the input stream EOF. */
+    private boolean eof;
 
     /**
-     * Creates a new instance, which filters the given input stream, and
-     * uses the given buffer size.
+     * Creates a new instance, which filters the given input stream, and uses the given buffer size.
      *
-     * @param inputStream         The input stream, which is being buffered.
-     * @param bufferSize The size of the {@link CircularByteBuffer}, which is
-     *                    used internally.
+     * @param inputStream The input stream, which is being buffered.
+     * @param bufferSize The size of the {@link CircularByteBuffer}, which is used internally.
      */
     public CircularBufferInputStream(final InputStream inputStream, final int bufferSize) {
         if (bufferSize <= 0) {
@@ -49,12 +55,12 @@ public CircularBufferInputStream(final InputStream inputStream, final int buffer
         this.in = Objects.requireNonNull(inputStream, "inputStream");
         this.buffer = new CircularByteBuffer(bufferSize);
         this.bufferSize = bufferSize;
-        this.eofSeen = false;
+        this.eof = false;
     }
 
     /**
-     * Creates a new instance, which filters the given input stream, and
-     * uses a reasonable default buffer size ({@link IOUtils#DEFAULT_BUFFER_SIZE}).
+     * Creates a new instance, which filters the given input stream, and uses a reasonable default buffer size
+     * ({@link IOUtils#DEFAULT_BUFFER_SIZE}).
      *
      * @param inputStream The input stream, which is being buffered.
      */
@@ -68,15 +74,15 @@ public CircularBufferInputStream(final InputStream inputStream) {
      * @throws IOException in case of an error while reading from the input stream.
      */
     protected void fillBuffer() throws IOException {
-        if (eofSeen) {
+        if (eof) {
             return;
         }
         int space = buffer.getSpace();
         final byte[] buf = new byte[space];
         while (space > 0) {
             final int res = in.read(buf, 0, space);
-            if (res == -1) {
-                eofSeen = true;
+            if (res == EOF) {
+                eof = true;
                 return;
             } else if (res > 0) {
                 buffer.add(buf, 0, res);
@@ -102,7 +108,7 @@ protected boolean haveBytes(final int count) throws IOException {
     @Override
     public int read() throws IOException {
         if (!haveBytes(1)) {
-            return -1;
+            return EOF;
         }
         return buffer.read() & 0xFF; // return unsigned byte
     }
@@ -114,15 +120,15 @@ public int read(final byte[] buffer) throws IOException {
 
     @Override
     public int read(final byte[] targetBuffer, final int offset, final int length) throws IOException {
-        Objects.requireNonNull(targetBuffer, "Buffer");
+        Objects.requireNonNull(targetBuffer, "targetBuffer");
         if (offset < 0) {
             throw new IllegalArgumentException("Offset must not be negative");
         }
         if (length < 0) {
             throw new IllegalArgumentException("Length must not be negative");
         }
         if (!haveBytes(length)) {
-            return -1;
+            return EOF;
         }
         final int result = Math.min(length, buffer.getCurrentNumberOfBytes());
         for (int i = 0; i < result; i++) {
@@ -134,7 +140,7 @@ public int read(final byte[] targetBuffer, final int offset, final int length) t
     @Override
     public void close() throws IOException {
         in.close();
-        eofSeen = true;
+        eof = true;
         buffer.clear();
     }
 }

src/main/java/org/apache/commons/io/input/buffer/PeekableInputStream.java

@@ -20,29 +20,24 @@
 import java.io.InputStream;
 import java.util.Objects;
 
-
 /**
- * Implementation of a buffered input stream, which allows to peek into
- * the buffers first bytes. This comes in handy when manually implementing
- * scanners, lexers, parsers, or the like.
+ * Implements a buffered input stream, which allows to peek into the buffers first bytes. This comes in handy when
+ * manually implementing scanners, lexers, parsers, and the like.
  */
 public class PeekableInputStream extends CircularBufferInputStream {
 
     /**
-     * Creates a new instance, which filters the given input stream, and
-     * uses the given buffer size.
+     * Creates a new instance, which filters the given input stream, and uses the given buffer size.
      *
-     * @param inputStream         The input stream, which is being buffered.
-     * @param bufferSize The size of the {@link CircularByteBuffer}, which is
-     *                    used internally.
+     * @param inputStream The input stream, which is being buffered.
+     * @param bufferSize The size of the {@link CircularByteBuffer}, which is used internally.
      */
     public PeekableInputStream(final InputStream inputStream, final int bufferSize) {
         super(inputStream, bufferSize);
     }
 
     /**
-     * Creates a new instance, which filters the given input stream, and
-     * uses a reasonable default buffer size (8192).
+     * Creates a new instance, which filters the given input stream, and uses a reasonable default buffer size (8192).
      *
      * @param inputStream The input stream, which is being buffered.
      */
@@ -51,29 +46,21 @@ public PeekableInputStream(final InputStream inputStream) {
     }
 
     /**
-     * Returns, whether the next bytes in the buffer are as given by
-     * {@code sourceBuffer}. This is equivalent to {@link #peek(byte[], int, int)}
-     * with {@code offset} == 0, and {@code length} == {@code sourceBuffer.length}
+     * Returns whether the next bytes in the buffer are as given by {@code sourceBuffer}. This is equivalent to
+     * {@link #peek(byte[], int, int)} with {@code offset} == 0, and {@code length} == {@code sourceBuffer.length}
      *
      * @param sourceBuffer the buffer to compare against
      * @return true if the next bytes are as given
      * @throws IOException Refilling the buffer failed.
      */
     public boolean peek(final byte[] sourceBuffer) throws IOException {
-        Objects.requireNonNull(sourceBuffer, "Buffer");
-        if (sourceBuffer.length > bufferSize) {
-            throw new IllegalArgumentException("Peek request size of " + sourceBuffer.length
-                    + " bytes exceeds buffer size of " + bufferSize + " bytes");
-        }
-        if (buffer.getCurrentNumberOfBytes() < sourceBuffer.length) {
-            fillBuffer();
-        }
-        return buffer.peek(sourceBuffer, 0, sourceBuffer.length);
+        Objects.requireNonNull(sourceBuffer, "sourceBuffer");
+        return peek(sourceBuffer, 0, sourceBuffer.length);
     }
 
     /**
-     * Returns, whether the next bytes in the buffer are as given by
-     * {@code sourceBuffer}, {code offset}, and {@code length}.
+     * Returns whether the next bytes in the buffer are as given by {@code sourceBuffer}, {code offset}, and
+     * {@code length}.
      *
      * @param sourceBuffer the buffer to compare against
      * @param offset the start offset
@@ -82,10 +69,10 @@ public boolean peek(final byte[] sourceBuffer) throws IOException {
      * @throws IOException if there is a problem calling fillBuffer()
      */
     public boolean peek(final byte[] sourceBuffer, final int offset, final int length) throws IOException {
-        Objects.requireNonNull(sourceBuffer, "Buffer");
+        Objects.requireNonNull(sourceBuffer, "sourceBuffer");
         if (sourceBuffer.length > bufferSize) {
             throw new IllegalArgumentException("Peek request size of " + sourceBuffer.length
-                    + " bytes exceeds buffer size of " + bufferSize + " bytes");
+                + " bytes exceeds buffer size of " + bufferSize + " bytes");
         }
         if (buffer.getCurrentNumberOfBytes() < sourceBuffer.length) {
             fillBuffer();