org.glassfish.grizzly.utils.StringEncoder Maven / Gradle / Ivy

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package org.glassfish.grizzly.utils;

import org.glassfish.grizzly.attributes.AttributeStorage;
import java.io.UnsupportedEncodingException;
import java.nio.charset.Charset;
import org.glassfish.grizzly.AbstractTransformer;
import org.glassfish.grizzly.Buffer;
import org.glassfish.grizzly.TransformationException;
import org.glassfish.grizzly.TransformationResult;

/**
 * String decoder, which decodes {@link Buffer} to {@link String}
 *
 * @author Alexey Stashok
 */
public class StringEncoder extends AbstractTransformer {

    protected Charset charset;

    protected String stringTerminator = null;

    public StringEncoder() {
        this((String) null);
    }

    public StringEncoder(String stringTerminator) {
        this(null, null);
    }

    public StringEncoder(Charset charset) {
        this(charset, null);
    }

    public StringEncoder(Charset charset, String stringTerminator) {
        if (charset != null) {
            this.charset = charset;
        } else {
            this.charset = Charset.defaultCharset();
        }

        this.stringTerminator = stringTerminator;
    }

    @Override
    public String getName() {
        return "StringEncoder";
    }

    @Override
    protected TransformationResult transformImpl(
            AttributeStorage storage, String input)
            throws TransformationException {

        if (input == null) {
            throw new TransformationException("Input could not be null");
        }

        byte[] byteRepresentation;
        try {
            if (stringTerminator != null) {
                input = input + stringTerminator;
            }
            
            byteRepresentation = input.getBytes(charset.name());
        } catch(UnsupportedEncodingException e) {
            throw new TransformationException("Charset " +
                    charset.name() + " is not supported", e);
        }

        final Buffer output =
                obtainMemoryManager(storage).allocate(byteRepresentation.length + 4);

        if (stringTerminator == null) {
            output.putInt(byteRepresentation.length);
        }

        output.put(byteRepresentation);

        output.flip();
        output.allowBufferDispose(true);

        return TransformationResult.createCompletedResult(output, null);
    }

    @Override
    public boolean hasInputRemaining(AttributeStorage storage, String input) {
        return input != null;
    }

    public Charset getCharset() {
        return charset;
    }

    public void setCharset(Charset charset) {
        this.charset = charset;
    }
}