FlowChartManager.java

package org.maltparser.core.flow;

import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.HashMap;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.maltparser.core.exception.MaltChainedException;
import org.maltparser.core.feature.FeatureException;
import org.maltparser.core.flow.spec.ChartSpecification;
import org.maltparser.core.flow.system.FlowChartSystem;
import org.maltparser.core.helper.URLFinder;
import org.maltparser.core.plugin.Plugin;
import org.maltparser.core.plugin.PluginLoader;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

/**
 *
 *
 * @author Johan Hall
 */
public class FlowChartManager {

    private static FlowChartManager uniqueInstance = new FlowChartManager();
    private final FlowChartSystem flowChartSystem;
    private final HashMap<String, ChartSpecification> chartSpecifications;

    public FlowChartManager() {
        flowChartSystem = new FlowChartSystem();
        chartSpecifications = new HashMap<String, ChartSpecification>();
    }

    /**
     * Returns a reference to the single instance.
     */
    public static FlowChartManager instance() {
        return uniqueInstance;
    }

    public void load(String urlstring) throws MaltChainedException {
        final URLFinder f = new URLFinder();
        load(f.findURL(urlstring));
    }

    public void load(PluginLoader plugins) throws MaltChainedException {
        for (Plugin plugin : plugins) {
            URL url = null;
            try {
                url = new URL("jar:" + plugin.getUrl() + "!/appdata/plugin.xml");
            } catch (MalformedURLException e) {
                throw new FeatureException("Malformed URL: 'jar:" + plugin.getUrl() + "!plugin.xml'", e);
            }
            try {
                InputStream is = url.openStream();
                is.close();
            } catch (IOException e) {
                continue;
            }

            load(url);
        }
    }

    public void load(URL url) throws MaltChainedException {
        try {
            DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
            DocumentBuilder db = dbf.newDocumentBuilder();
            Element root = db.parse(url.openStream()).getDocumentElement();
            if (root == null) {
                throw new FlowException("The flow chart specification file '" + url.getFile() + "' cannot be found. ");
            }
            readFlowCharts(root);
        } catch (IOException e) {
            throw new FlowException("The flow chart specification file '" + url.getFile() + "' cannot be found. ", e);
        } catch (ParserConfigurationException e) {
            throw new FlowException("Problem parsing the flow chart file " + url.getFile() + ". ", e);
        } catch (SAXException e) {
            throw new FlowException("Problem parsing the flow chart file " + url.getFile() + ". ", e);
        }
    }

    private void readFlowCharts(Element flowcharts) throws MaltChainedException {
        NodeList flowChartList = flowcharts.getElementsByTagName("flowchart");
        for (int i = 0; i < flowChartList.getLength(); i++) {
            String flowChartName = ((Element) flowChartList.item(i)).getAttribute("name");
            if (!chartSpecifications.containsKey(flowChartName)) {
                ChartSpecification chart = new ChartSpecification();
                chartSpecifications.put(flowChartName, chart);
                chart.read((Element) flowChartList.item(i), this);
            } else {
                throw new FlowException("Problem parsing the flow chart file. The flow chart with the name " + flowChartName + " already exists. ");
            }
        }
    }

    public FlowChartInstance initialize(int optionContainerIndex, String flowChartName) throws MaltChainedException {
        return new FlowChartInstance(optionContainerIndex, chartSpecifications.get(flowChartName), this);
    }

    public FlowChartSystem getFlowChartSystem() {
        return flowChartSystem;
    }

    @Override
    public String toString() {
        final StringBuilder sb = new StringBuilder();
        sb.append("FLOW CHART SYSTEM\n");
        sb.append(flowChartSystem);
        sb.append('\n');
        sb.append("FLOW CHARTS:\n");
        for (String key : chartSpecifications.keySet()) {
            sb.append(chartSpecifications.get(key));
            sb.append('\n');
        }
        return sb.toString();
    }
}