com.ikanow.aleph2.storm.samples.script.PropertyBasedScriptProvider.java Source code

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Here is the source code for com.ikanow.aleph2.storm.samples.script.PropertyBasedScriptProvider.java

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/*******************************************************************************
 * Copyright 2015, The IKANOW Open Source Project.
 *
 * 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 com.ikanow.aleph2.storm.samples.script;

import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Map.Entry;
import java.util.Properties;

import org.apache.commons.io.IOUtils;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

public class PropertyBasedScriptProvider implements IScriptProvider, Serializable {
    /**
     * 
     */
    private static final long serialVersionUID = -8941606773988212019L;

    private static final Logger logger = LogManager.getLogger(PropertyBasedScriptProvider.class);

    protected Properties properties;
    protected List<String> scriptlets = new ArrayList<String>();
    protected String globalScript = null;

    protected static String GLOBAL = "global";

    public PropertyBasedScriptProvider(String propertiesFileName) {
        init(propertiesFileName);
    }

    public void init(String propertiesFileName) {
        loadProperties(propertiesFileName);
        File propFile = new File(propertiesFileName);
        String parentFolder = propFile.getParent();

        for (Iterator<Entry<Object, Object>> it = properties.entrySet().iterator(); it.hasNext();) {
            Entry<Object, Object> entry = it.next();

            if (entry.getKey().toString().equalsIgnoreCase(GLOBAL)) {
                globalScript = loadScriptFromResource(parentFolder, (String) entry.getValue());
            } // if
            else {
                String scriptlet = loadScriptFromResource(parentFolder, (String) entry.getValue());
                scriptlets.add(scriptlet);
            }
        } // for      
    }

    @Override
    public List<String> getScriptlets() {
        return scriptlets;
    }

    @Override
    public String getGlobalScript() {
        return globalScript;
    }

    protected void loadProperties(String propertiesFileName) {
        this.properties = new Properties();

        try {
            InputStream inStream = PropertyBasedScriptProvider.class.getResourceAsStream(propertiesFileName);
            if (inStream == null) {
                // second try
                inStream = new FileInputStream(propertiesFileName);
            }
            properties.load(inStream);

        } catch (Throwable t) {
            logger.error("Caught exception loading properties:", t);
        }
    }

    protected static String loadScriptFromResource(String parentFolder, String resourcePathToJSFile) {
        String script = null;
        if (resourcePathToJSFile != null) {
            String filePath = (parentFolder != null ? parentFolder : "") + File.separator + resourcePathToJSFile;
            try {
                InputStream inStream = PropertyBasedScriptProvider.class.getResourceAsStream(filePath);
                if (inStream == null) {
                    // second try
                    inStream = new FileInputStream(resourcePathToJSFile);
                }
                script = IOUtils.toString(inStream, "UTF-8");

            } catch (Throwable t) {
                logger.error("Caught exception loading resource:", t);
            }
        }
        return script;
    }

}