org.metafacture.io.ObjectStdoutWriter Maven / Gradle / Ivy

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/*
 * Copyright 2013, 2014 Deutsche Nationalbibliothek
 *
 * Licensed under the Apache License, Version 2.0 the "License";
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * 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.
 */

package org.metafacture.io;

import org.metafacture.framework.FluxCommand;
import org.metafacture.framework.annotations.Description;
import org.metafacture.framework.annotations.In;

import java.nio.charset.Charset;

/**
 * @param  object type
 *
 * @author Christoph Böhme
 *
 */

@Description("Writes objects to stdout")
@In(Object.class)
@FluxCommand("print")
public final class ObjectStdoutWriter extends AbstractObjectWriter  {

    private static final String SET_COMPRESSION_ERROR = "Cannot compress standard out";

    private boolean firstObject = true;
    private boolean closed;

    /**
     * Creates an instance of {@link ObjectStdoutWriter}.
     */
    public ObjectStdoutWriter() {
    }

    @Override
    public String getEncoding() {
        return Charset.defaultCharset().toString();
    }

    @Override
    public void setEncoding(final String encoding) {
        throw new UnsupportedOperationException("Cannot change encoding of standard out");
    }

    @Override
    public FileCompression getCompression() {
        return FileCompression.NONE;
    }

    @Override
    public void setCompression(final FileCompression compression) {
        throw new UnsupportedOperationException(SET_COMPRESSION_ERROR);
    }

    @Override
    public void setCompression(final String compression) {
        throw new UnsupportedOperationException(SET_COMPRESSION_ERROR);
    }

    @Override
    public void process(final T obj) {
        assert !closed;

        if (firstObject) {
            System.out.print(getHeader());
            firstObject = false;
        }
        else {
            System.out.print(getSeparator());
        }
        System.out.print(obj);
    }

    @Override
    public void resetStream() {
        firstObject = true;
    }

    @Override
    public void closeStream() {
        if (!firstObject) {
            System.out.print(getFooter());
        }
        closed = true;
    }

}