com.ewcms.publication.freemarker.loader.DatabaseTemplateLoader.java Source code

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Here is the source code for com.ewcms.publication.freemarker.loader.DatabaseTemplateLoader.java

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/**
 * Copyright (c)2010-2011 Enterprise Website Content Management System(EWCMS), All rights reserved.
 * EWCMS PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 * http://www.ewcms.com
 */

package com.ewcms.publication.freemarker.loader;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;

import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.util.Assert;

import com.ewcms.publication.dao.TemplatePublishDaoable;
import com.ewcms.publication.module.TemplateBody;

import freemarker.cache.TemplateLoader;

/**
 * ??
 * 
 * @author <a href="hhywangwei@gmail.com"></a>
 */
public class DatabaseTemplateLoader implements TemplateLoader {
    private static final Logger logger = LoggerFactory.getLogger(DatabaseTemplateLoader.class);

    private TemplatePublishDaoable templatePublishDao;

    public DatabaseTemplateLoader(TemplatePublishDaoable templatePublishDao) {
        this.templatePublishDao = templatePublishDao;
    }

    @Override
    public Object findTemplateSource(String name) throws IOException {
        Assert.notNull(name, "template uniquepath is null");

        String path = StringUtils.removeStart(name, "/");
        TemplateBody body = templatePublishDao.findBody(path);

        if (body == null) {
            logger.debug("{} is not exist.", path);
            return null;
        }

        byte[] content = body.getBody();
        long lastTime = System.currentTimeMillis();

        return new TemplateSource(path, content, lastTime);
    }

    @Override
    public Reader getReader(Object templateSource, String encoding) throws IOException {
        TemplateSource source = (TemplateSource) templateSource;
        try {
            return new InputStreamReader(new ByteArrayInputStream(source.source), encoding);
        } catch (IOException e) {
            logger.debug("Could not find FreeMarker template:{} " + source.name);
            throw e;
        }
    }

    @Override
    public long getLastModified(Object templateSource) {
        return ((TemplateSource) templateSource).lastModified;
    }

    @Override
    public void closeTemplateSource(Object templateSource) throws IOException {
        //Do nothing
    }

    private static class TemplateSource {
        private final String name;
        private final byte[] source;
        private final long lastModified;

        TemplateSource(String name, byte[] source, long lastModified) {
            if (name == null) {
                throw new IllegalArgumentException("name == null");
            }
            if (source == null) {
                throw new IllegalArgumentException("source == null");
            }
            if (lastModified < -1L) {
                throw new IllegalArgumentException("lastModified < -1L");
            }
            this.name = name;
            this.source = source;
            this.lastModified = lastModified;
        }

        @Override
        public boolean equals(Object obj) {
            if (obj instanceof TemplateSource) {
                return name.equals(((TemplateSource) obj).name);
            }
            return false;
        }

        @Override
        public int hashCode() {
            return name.hashCode();
        }
    }
}