--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/flys-artifacts/src/main/java/org/dive4elements/river/exports/AbstractExporter.java	Thu Apr 25 12:06:39 2013 +0200
@@ -0,0 +1,346 @@
+package org.dive4elements.river.exports;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.io.OutputStreamWriter;
+
+import java.text.NumberFormat;
+
+import org.w3c.dom.Document;
+
+import org.apache.log4j.Logger;
+
+import au.com.bytecode.opencsv.CSVWriter;
+
+import org.dive4elements.artifacts.Artifact;
+import org.dive4elements.artifacts.CallContext;
+
+import org.dive4elements.artifactdatabase.state.ArtifactAndFacet;
+import org.dive4elements.artifactdatabase.state.Settings;
+
+import org.dive4elements.artifacts.common.ArtifactNamespaceContext;
+import org.dive4elements.artifacts.common.utils.XMLUtils;
+
+import org.dive4elements.river.artifacts.resources.Resources;
+import org.dive4elements.river.collections.FLYSArtifactCollection;
+
+import org.dive4elements.river.utils.Formatter;
+
+
+/**
+ * An abstract exporter that implements some basic methods for exporting data of
+ * artifacts.
+ *
+ * @author <a href="mailto:ingo.weinzierl@intevation.de">Ingo Weinzierl</a>
+ */
+public abstract class AbstractExporter implements OutGenerator {
+
+    /** The logger used in this exporter.*/
+    private static Logger logger = Logger.getLogger(AbstractExporter.class);
+
+    /* XXX: Why does AbstractExporter do not implement FacetTypes? */
+    public static String FIX_PARAMETERS = "fix_parameters";
+
+    /** The name of the CSV facet which triggers the CSV creation. */
+    public static final String FACET_CSV = "csv";
+
+    /** The name of the PDF facet which triggers the PDF creation. */
+    public static final String FACET_PDF = "pdf";
+
+    /** The default charset for the CSV export. */
+    public static final String DEFAULT_CSV_CHARSET = "UTF-8";
+
+    /** The default separator for the CSV export. */
+    public static final char DEFAULT_CSV_SEPARATOR = ',';
+
+    /** XPath that points to the desired export facet. */
+    public static final String XPATH_FACET = "/art:action/@art:type";
+
+    /** The document of the incoming out() request. */
+    protected Document request;
+
+    /** The output stream where the data should be written to. */
+    protected OutputStream out;
+
+    /** The CallContext object. */
+    protected CallContext context;
+
+    /** The selected facet. */
+    protected String facet;
+
+    /** The collection.*/
+    protected FLYSArtifactCollection collection;
+
+    /** The master artifact. */
+    protected Artifact master;
+
+    private NumberFormat kmFormat;
+
+    private NumberFormat wFormat;
+
+    private NumberFormat qFormat;
+
+
+    /**
+     * Concrete subclasses need to use this method to write their special data
+     * objects into the CSV document.
+     *
+     * @param writer The CSVWriter.
+     */
+    protected abstract void writeCSVData(CSVWriter writer) throws IOException;
+
+
+    /**
+     * Concrete subclasses need to use this method to write their special data
+     * objects into the PDF document.
+     */
+    protected abstract void writePDF(OutputStream out);
+
+
+    /**
+     * This method enables concrete subclasses to collected its own special
+     * data.
+     *
+     * @param data The artifact that stores the data that has to be
+     * exported.
+     */
+    protected abstract void addData(Object data);
+
+
+    @Override
+    public void init(Document request, OutputStream out, CallContext context) {
+        logger.debug("AbstractExporter.init");
+
+        this.request = request;
+        this.out     = out;
+        this.context = context;
+    }
+
+
+    @Override
+    public void setMasterArtifact(Artifact master) {
+        this.master = master;
+    }
+
+    /** Get the callcontext that this exporter has been initialized
+     * with. */
+    public CallContext getCallContext() {
+        return this.context;
+    }
+
+
+    @Override
+    public void setCollection(FLYSArtifactCollection collection) {
+        this.collection = collection;
+    }
+
+
+    /**
+     * This doOut() just collects the data of multiple artifacts. Therefore, it
+     * makes use of the addData() method which enables concrete subclasses to
+     * store its data on its own. The real output creation takes place in the
+     * concrete generate() methods.
+     *
+     * @param artifactFacet The artifact and facet.
+     * The facet to add - NOTE: the facet needs to fit to the first
+     * facet inserted into this exporter. Otherwise this artifact/facet is
+     * skipped.
+     * @param attr The attr document.
+     */
+    @Override
+    public void doOut(
+        ArtifactAndFacet artifactFacet,
+        Document         attr,
+        boolean          visible
+    ) {
+        String name = artifactFacet.getFacetName();
+
+        logger.debug("AbstractExporter.doOut: " + name);
+
+        if (!isFacetValid(name)) {
+            logger.warn("Facet '" + name + "' not valid. No output created!");
+            return;
+        }
+
+        addData(artifactFacet.getData(context));
+    }
+
+
+    /**
+     * Generates an export based on a specified facet.
+     */
+    @Override
+    public void generate()
+    throws IOException
+    {
+        logger.debug("AbstractExporter.generate");
+
+        if (facet == null) {
+            throw new IOException("invalid (null) facet for exporter");
+        }
+
+        if (facet.equals(FACET_CSV)) {
+            generateCSV();
+        }
+        else if (facet.equals(FACET_PDF)) {
+            generatePDF();
+        }
+        else {
+            throw new IOException(
+                "invalid facet for exporter: '" + facet + "'");
+        }
+    }
+
+
+    /**
+     * Determines if the desired facet is valid for this exporter. If no facet
+     * is currently set, <i>facet</i> is set.
+     *
+     * @param facet The desired facet.
+     *
+     * @return true, if <i>facet</i> is valid, otherwise false.
+     */
+    protected boolean isFacetValid(String facet) {
+        logger.debug("AbstractExporter.isFacetValid : " + facet + " (" + getFacet() + ")" );
+
+        String thisFacet = getFacet();
+
+        if (thisFacet == null || thisFacet.length() == 0) {
+            return false;
+        }
+        else if (facet == null || facet.length() == 0) {
+            return false;
+        }
+        else {
+            return thisFacet.equals(facet);
+        }
+    }
+
+
+    /**
+     * Returns the name of the desired facet.
+     *
+     * @return the name of the desired facet.
+     */
+    protected String getFacet() {
+        if (facet == null) {
+            facet = getFacetFromRequest();
+        }
+
+        return facet;
+    }
+
+
+    /**
+     * Extracts the name of the requested facet from request document.
+     *
+     * @return the name of the requested facet.
+     */
+    protected String getFacetFromRequest() {
+        return XMLUtils.xpathString(
+            request, XPATH_FACET, ArtifactNamespaceContext.INSTANCE);
+    }
+
+
+    protected String msg(String key, String def) {
+        return Resources.getMsg(context.getMeta(), key, def);
+    }
+
+    protected String msg(String key, String def, Object[] args) {
+        return Resources.getMsg(context.getMeta(), key, def, args);
+    }
+
+
+    /**
+     * This method starts CSV creation. It makes use of writeCSVData() which has
+     * to be implemented by concrete subclasses.
+     */
+    protected void generateCSV()
+    throws    IOException
+    {
+        logger.info("AbstractExporter.generateCSV");
+
+        char quote = '"';
+        char escape = '\\';
+
+        CSVWriter writer = new CSVWriter(
+            new OutputStreamWriter(
+                out,
+                DEFAULT_CSV_CHARSET),
+            DEFAULT_CSV_SEPARATOR, quote, escape, "\r\n");
+
+        writeCSVData(writer);
+
+        writer.close();
+    }
+
+
+    /**
+     * This method starts PDF creation.
+     */
+    protected void generatePDF()
+    throws    IOException
+    {
+        logger.info("AbstractExporter.generatePDF");
+        writePDF(this.out);
+    }
+
+
+    /**
+     * Returns an instance of <i>EmptySettings</i> currently!
+     *
+     * @return an instance of <i>EmptySettings</i>.
+     */
+    public Settings getSettings() {
+        return new EmptySettings();
+    }
+
+
+    /**
+     * This method is not implemented. Override it in subclasses if those need a
+     * <i>Settings</i> object.
+     */
+    public void setSettings(Settings settings) {
+        // do nothing
+    }
+
+
+    /**
+     * Returns the number formatter for kilometer values.
+     *
+     * @return the number formatter for kilometer values.
+     */
+    protected NumberFormat getKmFormatter() {
+        if (kmFormat == null) {
+            kmFormat = Formatter.getWaterlevelKM(context);
+        }
+        return kmFormat;
+    }
+
+
+    /**
+     * Returns the number formatter for W values.
+     *
+     * @return the number formatter for W values.
+     */
+    protected NumberFormat getWFormatter() {
+        if (wFormat == null) {
+            wFormat = Formatter.getWaterlevelW(context);
+        }
+        return wFormat;
+    }
+
+
+    /**
+     * Returns the number formatter for Q values.
+     *
+     * @return the number formatter for Q values.
+     */
+    protected NumberFormat getQFormatter() {
+        if (qFormat == null) {
+            qFormat = Formatter.getWaterlevelQ(context);
+        }
+        return qFormat;
+    }
+}
+// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :