FileLineConsumer.java

/*******************************************************************************
 * Copyright (c) 2012-2017 Codenvy, S.A.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *   Codenvy, S.A. - initial API and implementation
 *******************************************************************************/
package org.eclipse.che.api.core.util;

import org.eclipse.che.api.core.util.lineconsumer.ConsumerAlreadyClosedException;

import java.io.File;
import java.io.IOException;
import java.io.Writer;
import java.nio.charset.Charset;
import java.nio.file.Files;

/**
 * Consumes logs and writes them into file.
 * <br/>
 * This class is not thread safe.
 * Also see multithreaded implementation {@link org.eclipse.che.api.core.util.lineconsumer.ConcurrentFileLineConsumer}
 *
 * @author andrew00x
 * @author Mykola Morhun
 */
public class FileLineConsumer implements LineConsumer {
    private final File   file;
    private final Writer writer;

    private boolean isOpen;

    public FileLineConsumer(File file) throws IOException {
        this.file = file;
        writer = Files.newBufferedWriter(file.toPath(), Charset.defaultCharset());
        isOpen = true;
    }

    public File getFile() {
        return file;
    }

    @Override
    public void writeLine(String line) throws IOException {
        if (isOpen) {
            try {
                if (line != null) {
                    writer.write(line);
                }
                writer.write('\n');
                writer.flush();
            } catch (IOException e) {
                if ("Stream closed".equals(e.getMessage())) {
                    throw new ConsumerAlreadyClosedException(e.getMessage());
                }
                throw e;
            }
        }
    }

    @Override
    public void close() throws IOException {
        if (isOpen) {
            isOpen = false;
            writer.close();
        }
    }
}