edu.uiuc.ncsa.security.storage.data.MapConverter Maven / Gradle / Ivy

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package edu.uiuc.ncsa.security.storage.data;

import edu.uiuc.ncsa.security.core.Identifiable;
import edu.uiuc.ncsa.security.core.IdentifiableProvider;
import edu.uiuc.ncsa.security.core.XMLConverter;
import edu.uiuc.ncsa.security.core.exceptions.NotImplementedException;
import edu.uiuc.ncsa.security.storage.sql.internals.ColumnMap;

import java.util.List;
import java.util.Map;

/**
 * A class that converts between objects and maps. You must supply some key.
 * Created by Jeff Gaynor

 * on 4/13/12 at  11:38 AM
 */
public class MapConverter implements XMLConverter {
    public SerializationKeys keys;
    protected IdentifiableProvider provider;

    public SerializationKeys getKeys() {
        return keys;
    }

    public MapConverter(SerializationKeys keys, IdentifiableProvider provider) {
        this.keys = keys;
        this.provider = provider;
    }

    /**
     * Takes a map and returns an object of the given type, initialized with the values of the map.
     *
     * @param data
     * @return
     */
    public V fromMap(ConversionMap data) {
        return fromMap(data, null);
    }

    public V createIfNeeded(V v) {
        if (v == null) {
            v = provider.get(false);
        }
        return v;
    }

    public V fromMap(ConversionMap map, V v) {
        v = createIfNeeded(v);
        v.setIdentifier(map.getIdentifier(keys.identifier()));
        return v;

    }

    /**
     * Takes the value and writes the data to the map. The reason that the map is supplied is
     * that there are many specialized maps. It would place undue constraints on this class to try
     * and manage these as well.
     *
     * @param value
     * @param data
     */
    public void toMap(V value, ConversionMap data) {
        data.put(keys.identifier(), value.getIdentifierString());
    }

    /**
     * Given a set of attributes, create a new object whose properties are restricted to the given list of
     * attributes. Note the the {@link SerializationKeys} has a method {@link SerializationKeys#allKeys()}
     * that allows you to get every key for this object so you can simply remove what you do not want or need.
     *
     * @param v
     * @param attributes
     * @return
     */
    public V subset(V v, List attributes) {
        ColumnMap map = new ColumnMap();

        toMap(v, map);
        ColumnMap reducedMap = new ColumnMap();

        for (String key : attributes) {
            reducedMap.put(key, map.get(key));
        }
        // Have to always include the identifier.
        reducedMap.put(getKeys().identifier(), v.getIdentifierString());
        V x = fromMap(reducedMap, null);
        return x;

    }

    @Override
    public V fromMap(Map map, V v) {
        if (map instanceof ConversionMap) {
            return (V) fromMap((ConversionMap) map, v);
        }
        System.err.print("MapConverter.fromMap(): failed for " + v);
        throw new NotImplementedException("Error: not implement for non ConversionMap objects");
    }

    @Override
    public void toMap(V value, Map data) {
        if (data instanceof ConversionMap) {
            toMap(value, (ConversionMap) data);
            return;
        }
        System.err.print("MapConverter.toMap(): failed for " + data);
        throw new NotImplementedException("Error: not implement for non ConversionMap objects");

    }
}