org.opoo.press.source.SourceParserImpl.java Source code

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Here is the source code for org.opoo.press.source.SourceParserImpl.java

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/*
 * Copyright 2013 Alex Lin.
 *
 * 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.opoo.press.source;

import org.apache.commons.io.IOUtils;
import org.apache.commons.io.LineIterator;
import org.opoo.press.NoFrontMatterException;
import org.opoo.press.Source;
import org.opoo.press.SourceEntry;
import org.opoo.press.SourceParser;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.yaml.snakeyaml.Yaml;

import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.StringWriter;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

/**
 * @author Alex Lin
 *
 */
public class SourceParserImpl implements SourceParser {
    private static final Logger log = LoggerFactory.getLogger(SourceParserImpl.class);
    private Yaml yaml = new Yaml();

    /* (non-Javadoc)
     * @see org.opoo.press.SourceParser#parse(org.opoo.press.SourceEntry)
     */
    @Override
    public Source parse(SourceEntry sourceEntry) throws NoFrontMatterException {
        List<String> metaLines = new ArrayList<String>();
        List<String> contentLines = new ArrayList<String>();
        InputStream stream = null;
        List<String> currentList = metaLines;
        try {
            stream = new FileInputStream(sourceEntry.getFile());
            LineIterator iterator = IOUtils.lineIterator(stream, "UTF-8");

            if (!iterator.hasNext()) {
                throw new RuntimeException("File not content: " + sourceEntry.getFile());
            }

            String line = iterator.next();
            if (!isFrontMatterStartLine(line, sourceEntry)) {
                log.debug("Maybe a static file: " + sourceEntry.getFile());
                throw new NoFrontMatterException(sourceEntry);
            }

            boolean hasFrontMatterEndLine = false;
            //process headers
            while (iterator.hasNext()) {
                line = iterator.next();
                if (isFrontMatterEndLine(line)) {
                    hasFrontMatterEndLine = true;
                    currentList = contentLines;
                    continue;
                }
                currentList.add(line);
            }

            if (!hasFrontMatterEndLine) {
                log.debug("Maybe a static file: " + sourceEntry.getFile());
                throw new NoFrontMatterException(sourceEntry);
            }
        } catch (IOException e) {
            throw new RuntimeException(e);
        } finally {
            IOUtils.closeQuietly(stream);
        }

        StringWriter metaWriter = new StringWriter();
        StringWriter contentWriter = new StringWriter();
        try {
            IOUtils.writeLines(metaLines, null, metaWriter);
            IOUtils.writeLines(contentLines, null, contentWriter);
        } catch (IOException e) {
            throw new RuntimeException(e);
        } finally {
            IOUtils.closeQuietly(contentWriter);
            IOUtils.closeQuietly(metaWriter);
        }

        @SuppressWarnings("unchecked")
        Map<String, Object> map = (Map<String, Object>) yaml.load(metaWriter.toString());
        String content = contentWriter.toString();

        return new SimpleSource(sourceEntry, map, content);
    }

    private static boolean isFrontMatterStartLine(String line, SourceEntry sourceEntry) {
        if (Source.TRIPLE_DASHED_LINE.equals(line)) {
            return true;
        }
        if (line.length() == 4) {
            if (65279 == line.charAt(0) && Source.TRIPLE_DASHED_LINE.equals(line.substring(1))) {
                log.debug("UTF-8 with BOM file: " + sourceEntry.getFile());
                return true;
            }
        }
        return false;
    }

    private static boolean isFrontMatterEndLine(String line) {
        return Source.TRIPLE_DASHED_LINE.equals(line);
    }
}