Use final and remove trailing whitespace.

Author: Gary Gregory

checkstyle.xml

@@ -15,11 +15,9 @@ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
 -->
-
 <!DOCTYPE module PUBLIC
     "-//Checkstyle//DTD Checkstyle Configuration 1.2//EN"
     "https://checkstyle.org/dtds/configuration_1_2.dtd">
-
 <!-- commons lang customization of default Checkstyle behavior -->
 <module name="Checker">
   <property name="localeLanguage" value="en"/>
@@ -34,12 +32,18 @@ limitations under the License.
     <property name="max" value="160"/>
   </module>
   <module name="TreeWalker">
-    <module name="AvoidStarImport"/>
-    <module name="RedundantImport"/>
-    <module name="UnusedImports"/>
-    <module name="NeedBraces"/>
-    <module name="LeftCurly"/>
-    <module name="JavadocMethod">
-    </module>
+   <module name="AvoidStarImport"/>
+   <module name="RedundantImport"/>
+   <module name="UnusedImports"/>
+   <module name="NeedBraces"/>
+   <module name="LeftCurly"/>
+   <module name="JavadocMethod">
+   </module>
+   <!--  No Trailing whitespace -->
+   <module name="Regexp">
+     <property name="format" value="[ \t]+$"/>
+     <property name="illegalPattern" value="true"/>
+     <property name="message" value="Trailing whitespace"/>
+   </module>
  </module>
 </module>

src/main/java/org/apache/commons/io/UncheckedIOExceptions.java

@@ -33,11 +33,11 @@ public class UncheckedIOExceptions {
      * <p>
      * This method exists because there is no String constructor in UncheckedIOException.
      * </p>
-     * 
+     *
      * @param message the detail message.
      * @return a new UncheckedIOException.
      */
-    public static UncheckedIOException create(Object message) {
+    public static UncheckedIOException create(final Object message) {
         final String string = Objects.toString(message);
         return new UncheckedIOException(string, new IOException(string));
     }
@@ -47,12 +47,12 @@ public static UncheckedIOException create(Object message) {
      * <p>
      * This method exists because there is no String constructor in UncheckedIOException.
      * </p>
-     * 
+     *
      * @param message the detail message.
      * @param e cause the {@code IOException}.
      * @return a new UncheckedIOException.
      */
-    public static UncheckedIOException create(Object message, final IOException e) {
+    public static UncheckedIOException create(final Object message, final IOException e) {
         return new UncheckedIOException(Objects.toString(message), e);
     }
 

src/main/java/org/apache/commons/io/file/PathUtils.java

@@ -813,7 +813,7 @@ public static DirectoryStream<Path> newDirectoryStream(final Path dir, final Pat
     /**
      * Creates a new OutputStream by opening or creating a file, returning an output stream that may be used to write bytes
      * to the file.
-     * 
+     *
      * @param path the Path.
      * @param append Whether or not to append.
      *
@@ -825,7 +825,7 @@ public static DirectoryStream<Path> newDirectoryStream(final Path dir, final Pat
     public static OutputStream newOutputStream(final Path path, final boolean append) throws IOException {
         // @formatter:off
         return Files.newOutputStream(path, append ?
-            new OpenOption[] {StandardOpenOption.CREATE, StandardOpenOption.APPEND} : 
+            new OpenOption[] {StandardOpenOption.CREATE, StandardOpenOption.APPEND} :
             new OpenOption[] {StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING});
         // @formatter:on
     }

src/main/java/org/apache/commons/io/input/BrokenInputStream.java

@@ -37,7 +37,7 @@ public class BrokenInputStream extends InputStream {
      * @since 2.12.0
      */
     public static final BrokenInputStream INSTANCE = new BrokenInputStream();
-    
+
     /**
      * The exception that is thrown by all methods of this class.
      */

src/main/java/org/apache/commons/io/output/FileWriterWithEncoding.java

@@ -240,7 +240,7 @@ public FileWriterWithEncoding(final String fileName, final String charsetName, f
 
     /**
      * Closes the stream.
-     * 
+     *
      * @throws IOException if an I/O error occurs.
      */
     @Override
@@ -250,7 +250,7 @@ public void close() throws IOException {
 
     /**
      * Flushes the stream.
-     * 
+     *
      * @throws IOException if an I/O error occurs.
      */
     @Override
@@ -260,7 +260,7 @@ public void flush() throws IOException {
 
     /**
      * Writes the characters from an array.
-     * 
+     *
      * @param chr the characters to write
      * @throws IOException if an I/O error occurs.
      */
@@ -271,7 +271,7 @@ public void write(final char[] chr) throws IOException {
 
     /**
      * Writes the specified characters from an array.
-     * 
+     *
      * @param chr the characters to write
      * @param st The start offset
      * @param end The number of characters to write
@@ -284,7 +284,7 @@ public void write(final char[] chr, final int st, final int end) throws IOExcept
 
     /**
      * Writes a character.
-     * 
+     *
      * @param idx the character to write
      * @throws IOException if an I/O error occurs.
      */
@@ -295,7 +295,7 @@ public void write(final int idx) throws IOException {
 
     /**
      * Writes the characters from a string.
-     * 
+     *
      * @param str the string to write
      * @throws IOException if an I/O error occurs.
      */
@@ -306,7 +306,7 @@ public void write(final String str) throws IOException {
 
     /**
      * Writes the specified characters from a string.
-     * 
+     *
      * @param str the string to write
      * @param st The start offset
      * @param end The number of characters to write

src/main/java/org/apache/commons/io/output/UncheckedFilterWriter.java

@@ -49,18 +49,18 @@ public static UncheckedFilterWriter on(final Writer writer) {
      * @param writer a Writer object providing the underlying stream.
      * @throws NullPointerException if {@code writer} is {@code null}.
      */
-    protected UncheckedFilterWriter(Writer writer) {
+    protected UncheckedFilterWriter(final Writer writer) {
         super(writer);
     }
 
     /**
      * Calls this method's super and rethrow {@link IOException} as {@link UncheckedIOException}.
      */
     @Override
-    public Writer append(char c) throws UncheckedIOException {
+    public Writer append(final char c) throws UncheckedIOException {
         try {
             return super.append(c);
-        } catch (IOException e) {
+        } catch (final IOException e) {
             throw uncheck(e);
         }
     }
@@ -69,10 +69,10 @@ public Writer append(char c) throws UncheckedIOException {
      * Calls this method's super and rethrow {@link IOException} as {@link UncheckedIOException}.
      */
     @Override
-    public Writer append(CharSequence csq) throws UncheckedIOException {
+    public Writer append(final CharSequence csq) throws UncheckedIOException {
         try {
             return super.append(csq);
-        } catch (IOException e) {
+        } catch (final IOException e) {
             throw uncheck(e);
         }
     }
@@ -81,10 +81,10 @@ public Writer append(CharSequence csq) throws UncheckedIOException {
      * Calls this method's super and rethrow {@link IOException} as {@link UncheckedIOException}.
      */
     @Override
-    public Writer append(CharSequence csq, int start, int end) throws UncheckedIOException {
+    public Writer append(final CharSequence csq, final int start, final int end) throws UncheckedIOException {
         try {
             return super.append(csq, start, end);
-        } catch (IOException e) {
+        } catch (final IOException e) {
             throw uncheck(e);
         }
     }
@@ -96,7 +96,7 @@ public Writer append(CharSequence csq, int start, int end) throws UncheckedIOExc
     public void close() throws UncheckedIOException {
         try {
             super.close();
-        } catch (IOException e) {
+        } catch (final IOException e) {
             throw uncheck(e);
         }
     }
@@ -108,23 +108,23 @@ public void close() throws UncheckedIOException {
     public void flush() throws UncheckedIOException {
         try {
             super.flush();
-        } catch (IOException e) {
+        } catch (final IOException e) {
             throw uncheck(e);
         }
     }
 
-    private UncheckedIOException uncheck(IOException e) {
+    private UncheckedIOException uncheck(final IOException e) {
         return new UncheckedIOException(e);
     }
 
     /**
      * Calls this method's super and rethrow {@link IOException} as {@link UncheckedIOException}.
      */
     @Override
-    public void write(char[] cbuf) throws UncheckedIOException {
+    public void write(final char[] cbuf) throws UncheckedIOException {
         try {
             super.write(cbuf);
-        } catch (IOException e) {
+        } catch (final IOException e) {
             throw uncheck(e);
         }
     }
@@ -133,10 +133,10 @@ public void write(char[] cbuf) throws UncheckedIOException {
      * Calls this method's super and rethrow {@link IOException} as {@link UncheckedIOException}.
      */
     @Override
-    public void write(char[] cbuf, int off, int len) throws UncheckedIOException {
+    public void write(final char[] cbuf, final int off, final int len) throws UncheckedIOException {
         try {
             super.write(cbuf, off, len);
-        } catch (IOException e) {
+        } catch (final IOException e) {
             throw uncheck(e);
         }
     }
@@ -145,10 +145,10 @@ public void write(char[] cbuf, int off, int len) throws UncheckedIOException {
      * Calls this method's super and rethrow {@link IOException} as {@link UncheckedIOException}.
      */
     @Override
-    public void write(int c) throws UncheckedIOException {
+    public void write(final int c) throws UncheckedIOException {
         try {
             super.write(c);
-        } catch (IOException e) {
+        } catch (final IOException e) {
             throw uncheck(e);
         }
     }
@@ -157,10 +157,10 @@ public void write(int c) throws UncheckedIOException {
      * Calls this method's super and rethrow {@link IOException} as {@link UncheckedIOException}.
      */
     @Override
-    public void write(String str) throws UncheckedIOException {
+    public void write(final String str) throws UncheckedIOException {
         try {
             super.write(str);
-        } catch (IOException e) {
+        } catch (final IOException e) {
             throw uncheck(e);
         }
     }
@@ -169,10 +169,10 @@ public void write(String str) throws UncheckedIOException {
      * Calls this method's super and rethrow {@link IOException} as {@link UncheckedIOException}.
      */
     @Override
-    public void write(String str, int off, int len) throws UncheckedIOException {
+    public void write(final String str, final int off, final int len) throws UncheckedIOException {
         try {
             super.write(str, off, len);
-        } catch (IOException e) {
+        } catch (final IOException e) {
             throw uncheck(e);
         }
     }

src/test/java/org/apache/commons/io/UncheckedIOExceptionsTest.java

@@ -31,7 +31,7 @@ public void testCreate() {
         final Object message = "test";
         try {
             throw UncheckedIOExceptions.create(message);
-        } catch (UncheckedIOException e) {
+        } catch (final UncheckedIOException e) {
             assertEquals(message, e.getMessage());
             assertEquals(message, e.getCause().getMessage());
         }
@@ -45,7 +45,7 @@ public void testCreateWithException() {
         final IOException ioe = new IOException(message2.toString());
         try {
             throw UncheckedIOExceptions.create(message1, ioe);
-        } catch (UncheckedIOException e) {
+        } catch (final UncheckedIOException e) {
             assertEquals(message1, e.getMessage());
             assertEquals(message2, e.getCause().getMessage());
         }

src/test/java/org/apache/commons/io/output/FileWriterWithEncodingTest.java

@@ -59,7 +59,7 @@ public void constructor_File_directory() {
         });
         assertFalse(file1.exists());
     }
-    
+
     @Test
     public void constructor_File_encoding_badEncoding() {
         assertThrows(IOException.class, () -> {