gov.nih.nci.cabig.caaers.service.FreeMarkerService.java Source code

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Here is the source code for gov.nih.nci.cabig.caaers.service.FreeMarkerService.java

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/*******************************************************************************
 * Copyright SemanticBits, Northwestern University and Akaza Research
 * 
 * Distributed under the OSI-approved BSD 3-Clause License.
 * See http://ncip.github.com/caaers/LICENSE.txt for details.
 ******************************************************************************/
package gov.nih.nci.cabig.caaers.service;

import java.io.IOException;
import java.io.StringReader;
import java.io.StringWriter;
import java.io.Writer;
import java.util.HashMap;
import java.util.Map;

import freemarker.core.Environment;
import freemarker.template.Configuration;
import freemarker.template.Template;
import freemarker.template.TemplateException;
import freemarker.template.TemplateExceptionHandler;
import gov.nih.nci.cabig.caaers.CaaersSystemException;
import org.apache.commons.io.IOUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * 
 * @author Biju Joseph
 *
 */
public class FreeMarkerService {
    protected final Log log = LogFactory.getLog(FreeMarkerService.class);

    /**
     * applyRuntimeReplacementsForReport
     * @param rawText
     * @param replacements
     * @return
     */
    public String applyRuntimeReplacementsForReport(final String rawText, final Map<Object, Object> replacements) {
        if (rawText == null)
            return "";

        //clean null values in Map
        final Map<Object, Object> variableMap = new HashMap<Object, Object>();
        if (replacements != null) {
            for (Map.Entry<Object, Object> entry : replacements.entrySet()) {
                if (entry.getValue() != null) {
                    variableMap.put(entry.getKey(), entry.getValue());
                } else {
                    log.warn("Entry value is null, ignoring key : " + entry.getKey());
                }
            }
        }

        Configuration cfg = new Configuration();
        cfg.setTemplateExceptionHandler(new TemplateExceptionHandler() {
            public void handleTemplateException(TemplateException e, Environment environment, Writer writer)
                    throws TemplateException {
                log.warn("Error while replacing variables", e);
                if (log.isDebugEnabled()) {
                    log.debug("rawText :" + rawText);
                    log.debug("variableMap :" + String.valueOf(variableMap));
                }
                try {
                    writer.write("_");
                } catch (IOException ignore) {
                }
            }
        });
        try {
            Template t = new Template("message", new StringReader(rawText), cfg);

            StringWriter writer = new StringWriter();
            t.process(variableMap, writer);
            return writer.toString();
        } catch (TemplateException e) {
            throw new CaaersSystemException("Error while applying freemarker template", e);
        } catch (IOException e) {
            throw new CaaersSystemException("Error while applying freemarker template", e);
        }
    }

}