ingo@391: package de.intevation.flys.exports;
ingo@391: 
ingo@391: import java.io.IOException;
ingo@391: import java.io.OutputStream;
ingo@391: import java.io.OutputStreamWriter;
ingo@391: 
ingo@391: import org.w3c.dom.Document;
ingo@391: 
ingo@391: import org.apache.log4j.Logger;
ingo@391: 
ingo@391: import au.com.bytecode.opencsv.CSVWriter;
ingo@391: 
ingo@391: import de.intevation.artifacts.Artifact;
ingo@391: import de.intevation.artifacts.CallContext;
ingo@391: 
ingo@416: import de.intevation.flys.artifacts.resources.Resources;
ingo@416: 
ingo@391: 
ingo@391: /**
ingo@391:  * An abstract exporter that implements some basic methods for exporting data of
ingo@391:  * artifacts.
ingo@391:  *
ingo@391:  * @author <a href="mailto:ingo.weinzierl@intevation.de">Ingo Weinzierl</a>
ingo@391:  */
ingo@391: public abstract class AbstractExporter implements OutGenerator {
ingo@391: 
ingo@391:     /** The logger used in this exporter.*/
ingo@391:     private static Logger logger = Logger.getLogger(AbstractExporter.class);
ingo@391: 
ingo@391: 
ingo@391:     /** The name of the CSV facet which triggers the CSV creation.*/
ingo@391:     public static final String FACET_CSV = "csv";
ingo@391: 
ingo@391:     /** The default charset for the CSV export.*/
ingo@391:     public static final String DEFAULT_CSV_CHARSET = "UTF-8";
ingo@391: 
ingo@391:     /** The default separator for the CSV export.*/
ingo@391:     public static final char DEFAULT_CSV_SEPARATOR = ',';
ingo@391: 
ingo@391: 
ingo@391:     /** The document of the incoming out() request.*/
ingo@391:     protected Document request;
ingo@391: 
ingo@391:     /** The output stream where the data should be written to.*/
ingo@391:     protected OutputStream out;
ingo@391: 
ingo@391:     /** The CallContext object.*/
ingo@391:     protected CallContext context;
ingo@391: 
ingo@391:     /** The selected facet.*/
ingo@391:     protected String facet;
ingo@391: 
ingo@412:     /** The master artifact.*/
ingo@412:     protected Artifact master;
ingo@412: 
ingo@391: 
ingo@391:     /**
ingo@391:      * Concrete subclasses need to use this method to write their special data
ingo@391:      * objects into the CSV document.
ingo@391:      *
ingo@391:      * @param writer The CSVWriter.
ingo@391:      */
ingo@391:     protected abstract void writeCSVData(CSVWriter writer);
ingo@391: 
ingo@391: 
ingo@391:     /**
ingo@391:      * This method enables concrete subclasses to collected its own special
ingo@391:      * data.
ingo@391:      *
ingo@391:      * @param artifacts The artifact that stores the data that has to be
ingo@391:      * exported.
ingo@391:      */
ingo@391:     protected abstract void addData(Artifact artifact);
ingo@391: 
ingo@391: 
ingo@391:     public void init(Document request, OutputStream out, CallContext context) {
ingo@391:         logger.debug("AbstractExporter.init");
ingo@391: 
ingo@391:         this.request = request;
ingo@391:         this.out     = out;
ingo@391:         this.context = context;
ingo@391:     }
ingo@391: 
ingo@391: 
ingo@412:     public void setMasterArtifact(Artifact master) {
ingo@412:         this.master = master;
ingo@412:     }
ingo@412: 
ingo@412: 
ingo@391:     /**
ingo@391:      * This doOut() just collects the data of multiple artifacts. Therefore, it
ingo@391:      * makes use of the addData() method which enables concrete subclasses to
ingo@391:      * store its data on its own. The real output creation takes place in the
ingo@391:      * concrete generate() methods.
ingo@391:      *
ingo@391:      * @param artifact The artifact.
ingo@391:      * @param facet The facet to add - NOTE: the facet needs to fit to the first
ingo@391:      * facet inserted into this exporter. Otherwise this artifact/facet is
ingo@391:      * skipped.
ingo@391:      * @param attr The attr document.
ingo@391:      */
ingo@391:     public void doOut(Artifact artifact, String facet, Document attr) {
ingo@391:         logger.debug("AbstractExporter.doOut: " + facet);
ingo@391: 
ingo@391:         if (!isFacetValid(facet)) {
ingo@391:             logger.warn("Facet '" + facet + "' not valid. No output created!");
ingo@391:             return;
ingo@391:         }
ingo@391: 
ingo@391:         addData(artifact);
ingo@391:     }
ingo@391: 
ingo@391: 
ingo@391:     /**
ingo@391:      * Generates an export based on a specified facet.
ingo@391:      */
ingo@391:     public void generate()
ingo@391:     throws IOException
ingo@391:     {
ingo@391:         logger.debug("AbstractExporter.generate");
ingo@391: 
ingo@391:         if (facet != null && facet.equals(FACET_CSV)) {
ingo@391:             generateCSV();
ingo@391:         }
ingo@391:         else {
ingo@391:             throw new IOException("invalid facet for exporter.");
ingo@391:         }
ingo@391:     }
ingo@391: 
ingo@391: 
ingo@391:     /**
ingo@391:      * Determines if the desired facet is valid for this exporter. If no facet
ingo@391:      * is currently set, <i>facet</i> is set.
ingo@391:      *
ingo@391:      * @param facet The desired facet.
ingo@391:      *
ingo@391:      * @return true, if <i>facet</i> is valid, otherwise false.
ingo@391:      */
ingo@391:     protected boolean isFacetValid(String facet) {
ingo@391:         logger.debug("AbstractExporter.isFacetValid");
ingo@391: 
ingo@391:         if (facet == null || facet.length() == 0) {
ingo@391:             return false;
ingo@391:         }
ingo@391:         else if (this.facet == null || this.facet.length() == 0) {
ingo@391:             logger.debug("Set the facet of this export: " + facet);
ingo@391:             this.facet = facet;
ingo@391: 
ingo@391:             return true;
ingo@391:         }
ingo@391:         else {
ingo@391:             return this.facet.equals(facet);
ingo@391:         }
ingo@391:     }
ingo@391: 
ingo@391: 
ingo@416: 
ingo@416:     protected String msg(String key, String def) {
ingo@416:         return Resources.getMsg(context.getMeta(), key, def);
ingo@416:     }
ingo@416: 
ingo@416: 
ingo@391:     /**
ingo@391:      * This method starts CSV creation. It makes use of writeCSVData() which has
ingo@391:      * to be implemented by concrete subclasses.
ingo@391:      */
ingo@391:     protected void generateCSV()
ingo@391:     throws    IOException
ingo@391:     {
ingo@391:         logger.info("AbstractExporter.generateCSV");
ingo@391: 
ingo@391:         CSVWriter writer = new CSVWriter(
ingo@391:             new OutputStreamWriter(
ingo@391:                 out,
ingo@391:                 DEFAULT_CSV_CHARSET),
ingo@391:             DEFAULT_CSV_SEPARATOR);
ingo@391: 
ingo@391:         writeCSVData(writer);
ingo@391: 
ingo@391:         writer.close();
ingo@391:     }
ingo@391: }
ingo@391: // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :