org.psikeds.common.config.ConfigLocationOverrider.java Source code

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Here is the source code for org.psikeds.common.config.ConfigLocationOverrider.java

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/*******************************************************************************
 * psiKeds :- ps induced knowledge entity delivery system
 * 
 * Copyright (c) 2013 Karsten Reincke, Marco Juliano, Deutsche Telekom AG
 * 
 * This file is free software: you can redistribute
 * it and/or modify it under the terms of the
 * [x] GNU Affero General Public License
 * [ ] GNU General Public License
 * [ ] GNU Lesser General Public License
 * [ ] Creatice Commons ShareAlike License
 * 
 * For details see file LICENSING in the top project directory
 *******************************************************************************/
package org.psikeds.common.config;

import java.io.File;
import java.io.FilenameFilter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.springframework.util.StringUtils;

/**
 * Helperfor replacing/overriding the location of spring context files: If a
 * file matching *context.xml or *properties.xml was requested and a
 * corresponding file exists in the config directory, then use that instead of
 * the original one packaged in the JAR/WAR/EAR.
 * 
 * @author marco@juliano.de
 */
class ConfigLocationOverrider {

    private static final Logger LOGGER = LoggerFactory.getLogger(ConfigLocationOverrider.class);
    private static final String CONFIG_LOCATION_DELIMITERS = ",; \t\n";

    private final File configDir;
    private final List<String> configFiles;

    // in order to avoid "dirt" in the config directory we only accept
    // filenames matching *context.xml or *properties.xml
    private final FilenameFilter springFilenameFilter = new FilenameFilter() {

        @Override
        public boolean accept(final File dir, final String name) {
            return StringUtils.endsWithIgnoreCase(name, "context.xml")
                    || StringUtils.endsWithIgnoreCase(name, "properties.xml");
        }
    };

    ConfigLocationOverrider() {
        this.configDir = ConfigDirectoryHelper.resolveConfigDir();
        final String[] contextFiles = this.configDir.list(this.springFilenameFilter);
        final int len = contextFiles == null ? 0 : contextFiles.length;
        if (len > 0) {
            this.configFiles = Arrays.asList(contextFiles);
            LOGGER.debug("Found {} config files.", len);
        } else {
            LOGGER.debug("No config files found!");
            this.configFiles = new ArrayList<String>();
        }
    }

    String getContextLocation(final String location) {
        String newloc = location;
        final String[] contextFiles = StringUtils.tokenizeToStringArray(location, CONFIG_LOCATION_DELIMITERS);
        for (final String contextFile : contextFiles) {
            final String overridingFile = findOverridingFile(contextFile);
            if (overridingFile != null) {
                newloc = location.replaceAll(contextFile, overridingFile);
            }
        }
        return newloc;
    }

    private String findOverridingFile(final String contextFile) {
        String overridingFile = null;
        final String shortFileName = new File(contextFile).getName();
        if (this.configFiles.contains(shortFileName)) {
            overridingFile = "file:" + this.configDir.getPath().replace('\\', '/') + "/" + shortFileName;
            LOGGER.info("Overriding spring context file {} with {}", contextFile, overridingFile);
        }
        return overridingFile;
    }
}