Decoder.java

/*
 * Copyright (c) 2015 Mozilla Foundation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a 
 * copy of this software and associated documentation files (the "Software"), 
 * to deal in the Software without restriction, including without limitation 
 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 
 * and/or sell copies of the Software, and to permit persons to whom the 
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in 
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
 * DEALINGS IN THE SOFTWARE.
 */

package nu.validator.encoding;
import java.nio.charset.Charset;
import java.nio.charset.CharsetDecoder;
import java.nio.charset.CodingErrorAction;

public abstract class Decoder extends CharsetDecoder {

    protected boolean report = true;
    
    protected Decoder(Charset cs, float averageCharsPerByte, float maxCharsPerByte) {
        super(cs, averageCharsPerByte, maxCharsPerByte);
    }

    @Override protected final void implOnMalformedInput(CodingErrorAction newAction) {
        if (newAction == null) {
            throw new IllegalArgumentException("The argument must not be null.");
        }
        if (newAction == CodingErrorAction.IGNORE) {
            throw new IllegalArgumentException("The Encoding Standard does not allow errors to be ignored.");
        }
        if (newAction == CodingErrorAction.REPLACE) {
            this.report = false;
            return;
        }
        if (newAction == CodingErrorAction.REPORT) {
            this.report = true;
            return;
        }
        assert false: "Unreachable.";
        throw new IllegalArgumentException("Unknown CodingErrorAction.");
    }

    @Override protected final void implOnUnmappableCharacter(
            CodingErrorAction newAction) {
        if (newAction == null) {
            throw new IllegalArgumentException("The argument must not be null.");
        }
        if (newAction == CodingErrorAction.IGNORE) {
            throw new IllegalArgumentException("The Encoding Standard does not allow errors to be ignored.");
        }
        if (newAction == CodingErrorAction.REPLACE) {
            return; // We don't actually care, since there are no unmappables.
        }
        if (newAction == CodingErrorAction.REPORT) {
            return; // We don't actually care, since there are no unmappables.
        }
        assert false: "Unreachable.";
        throw new IllegalArgumentException("Unknown CodingErrorAction.");
    }

    @Override protected final void implReplaceWith(String newReplacement) {
        if (!"\uFFFD".equals(newReplacement)) {
            throw new IllegalArgumentException("Only U+FFFD is allowed as the replacement.");
        }
    }
    
    // TODO: Check if the JDK decoders reset the reporting state on reset()
}