Classifier.java

package edu.ucla.nesl.mca.pmml;

import java.io.IOException;
import java.util.ArrayList;

import org.json.*;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

import edu.ucla.nesl.mca.feature.Feature;
import edu.ucla.nesl.mca.feature.FeaturePool;
import edu.ucla.nesl.mca.xdr.XDRSerializable;

public abstract class Classifier implements XDRSerializable{
    // Currently only support multiple in, single out
    protected ArrayList<Feature> m_inputs = null;
    protected Feature m_output = null;
    
    public void getMiningSchema(Element model, FeaturePool featurePool) 
            throws Exception {
        NodeList fieldList = model.getElementsByTagName("MiningField");
        for (int i = 0; i < fieldList.getLength(); i++) {
            Node miningField = fieldList.item(i);
            if (miningField.getNodeType() == Node.ELEMENT_NODE) {
                Element miningFieldEl = (Element)miningField;
                String fieldName = miningFieldEl.getAttribute("name");
                String usage = miningFieldEl.getAttribute("usageType");

                if (usage.compareTo("active") == 0 ||
                    usage.compareTo("predicted") == 0) {
                    Feature feature;
                    try {
                        feature = featurePool.get(fieldName);
                    } catch (IllegalArgumentException e) {
                        throw new Exception("Can't find mining field: " + fieldName 
                                + " in the data dictionary.");
                    }
                    
                    if (usage.compareTo("active") == 0) {
                        m_inputs.add(feature);
                    }
                    else { // predicted
                        m_output = feature;
                    }
                }
            }
        }
    }
    
    public static String getJSONModelType(String jsonString) throws IOException {
        try {
            JSONObject object = (JSONObject) new JSONTokener(jsonString).nextValue();
            JSONObject model = object.getJSONObject("Model");
            return model.getString("Type");
            
        } catch (JSONException e) {
            throw new IOException(e);
        }
    }
    
    public void parseJSON(String jsonString) throws IOException {
//        try {
//            JSONObject object = (JSONObject) new JSONTokener(jsonString).nextValue();
//            String name = object.getString("Name");
//            JSONArray featureList = object.getJSONArray("Feature List");
//            JSONObject model = object.getJSONObject("Model");
//            
//            for (int i = 0; i < featureList.length(); i++) {
//                JSONObject feature = featureList.getJSONObject(i);
//                boolean isResult = false;
//                if (object.has("isResult")) {
//                    isResult = object.getBoolean("isResult");
//                }
//                
//                Feature f = new Feature();
//            }
//            
//            this.getModel(model);
//            
//        } catch (JSONException e) {
//            throw new IOException(e);
//        }
    }

    protected abstract void getModel(JSONObject modelObj) throws JSONException;
}