Class URLCodec

src/main/java/org/apache/commons/codec/net/URLCodec.java:47–373

Implements the 'www-form-urlencoded' encoding scheme, also misleadingly known as URL encoding. This codec is meant to be a replacement for standard Java classes java.net.URLEncoder and java.net.URLDecoder on older Java platforms, as these classes in Java versions below 1.4 rely o

 * @since 1.2
 */
public class URLCodec implements BinaryEncoder, BinaryDecoder, StringEncoder, StringDecoder {

    /**
     * The default charset used for string decoding and encoding.
     *
     * @deprecated TODO: This field will be changed to a private final Charset in 2.0. (CODEC-126)
     */
    @Deprecated
    protected volatile String charset; // added volatile: see CODEC-232

    /**
     * Release 1.5 made this field final.
     */
    protected static final byte ESCAPE_CHAR = '%';

    /**
     * BitSet of www-form-url safe characters.
     * This is a copy of the internal BitSet which is now used for the conversion.
     * Changes to this field are ignored.
     * @deprecated 1.11 Will be removed in 2.0 (CODEC-230)
     */
    @Deprecated
    protected static final BitSet WWW_FORM_URL;

    private static final BitSet WWW_FORM_URL_SAFE = new BitSet(256);

    // Static initializer for www_form_url
    static {
        // alpha characters
        for (int i = 'a'; i <= 'z'; i++) {
            WWW_FORM_URL_SAFE.set(i);
        }
        for (int i = 'A'; i <= 'Z'; i++) {
            WWW_FORM_URL_SAFE.set(i);
        }
        // numeric characters
        for (int i = '0'; i <= '9'; i++) {
            WWW_FORM_URL_SAFE.set(i);
        }
        // special chars
        WWW_FORM_URL_SAFE.set('-');
        WWW_FORM_URL_SAFE.set('_');
        WWW_FORM_URL_SAFE.set('.');
        WWW_FORM_URL_SAFE.set('*');
        // blank to be replaced with +
        WWW_FORM_URL_SAFE.set(' ');

        // Create a copy in case anyone (ab)uses it
        WWW_FORM_URL = (BitSet) WWW_FORM_URL_SAFE.clone();
    }


    /**
     * Default constructor.
     */
    public URLCodec() {
        this(CharEncoding.UTF_8);
    }