FILEUPLOAD-312 - Use charset constant

src/main/java/org/apache/commons/fileupload2/FileUploadBase.java

@@ -19,7 +19,7 @@
 import static java.lang.String.format;
 
 import java.io.IOException;
-import java.io.UnsupportedEncodingException;
+import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.Iterator;
@@ -423,11 +423,7 @@ public byte[] getBoundary(final String contentType) {
             return null;
         }
         byte[] boundary;
-        try {
-            boundary = boundaryStr.getBytes("ISO-8859-1");
-        } catch (final UnsupportedEncodingException e) {
-            boundary = boundaryStr.getBytes(); // Intentionally falls back to default charset
-        }
+        boundary = boundaryStr.getBytes(StandardCharsets.ISO_8859_1);
         return boundary;
     }
 

src/main/java/org/apache/commons/fileupload2/util/mime/MimeUtility.java

@@ -19,6 +19,7 @@
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.UnsupportedEncodingException;
+import java.nio.charset.StandardCharsets;
 import java.util.HashMap;
 import java.util.Locale;
 import java.util.Map;
@@ -30,11 +31,6 @@
  */
 public final class MimeUtility {
 
-    /**
-     * The {@code US-ASCII} charset identifier constant.
-     */
-    private static final String US_ASCII_CHARSET = "US-ASCII";
-
     /**
      * The marker to indicate text is encoded with BASE64 algorithm.
      */
@@ -237,7 +233,7 @@ private static String decodeWord(final String word) throws ParseException, Unsup
             // the decoder writes directly to an output stream.
             final ByteArrayOutputStream out = new ByteArrayOutputStream(encodedText.length());
 
-            final byte[] encodedData = encodedText.getBytes(US_ASCII_CHARSET);
+            final byte[] encodedData = encodedText.getBytes(StandardCharsets.US_ASCII);
 
             // Base64 encoded?
             if (encoding.equals(BASE64_ENCODING_MARKER)) {