de.tsl2.nano.bean.def.MapExpressionFormat Maven / Gradle / Ivy

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/*
 * File: $HeadURL$
 * Id  : $Id$
 * 
 * created by: Thomas Schneider
 * created on: Jun 5, 2013
 * 
 * Copyright: (c) Thomas Schneider 2013, all rights reserved
 */
package de.tsl2.nano.bean.def;

import java.text.FieldPosition;
import java.text.ParsePosition;
import java.util.HashSet;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Set;

import de.tsl2.nano.core.ENV;
import de.tsl2.nano.core.util.Util;
import de.tsl2.nano.format.GenericTypeMatcher;

/**
 * Format for collections of entities/beans - not implementing it's own toString(). The format packs the given type into
 * a {@link BeanDefinition}, using the first attribute as output. See {@link ValueExpression} for further informations.
 * 
 * @author Thomas Schneider
 * @version $Revision$
 */
public class MapExpressionFormat extends ValueExpressionFormat {
    /** serialVersionUID */
    private static final long serialVersionUID = -3040338597603039966L;
    static final String DIV = "; ";

    /**
     * constructor to be serializeable
     */
    public MapExpressionFormat() {
        super();
    }

    /**
     * constructor
     * 
     * @param mapValueType type to format
     */
    public MapExpressionFormat(Class mapValueType) {
        super(mapValueType);
        //TODO: is previously done in super construction -> performance
        ve.setExpression("");
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public StringBuffer format(Object obj, StringBuffer toAppendTo, FieldPosition pos) {
        pos.setEndIndex(pos.getBeginIndex() + 1);
        Map m = (Map) obj;
        Set keySet = new HashSet(m.keySet());//aoid concurrentmodification exception (don't know why this occurs)
        for (Object key : keySet) {
            toAppendTo.append(key + "=" + ve.to(m.get(key)) + DIV);
        }
        if (m.size() > 0) {
            toAppendTo.delete(toAppendTo.length() - DIV.length(), toAppendTo.length());
        }
        return toAppendTo;
    }

    /**
     * {@inheritDoc}
     */
    @SuppressWarnings("unchecked")
    @Override
    public Object parseObject(String source, ParsePosition pos) {
        pos.setIndex(pos.getIndex() + 1);
        String[] s = source.split(DIV);
        Map m = new LinkedHashMap(s.length);
        if (!Util.isEmpty(source)) {
            GenericTypeMatcher matcher = ENV.get(GenericTypeMatcher.class);
            for (int i = 0; i < s.length; i++) {
                String kv[] = s[i].split("=");
                Object v = kv.length > 1 ? matcher.materialize(source) : null;
                m.put(kv[0], (T) v);
            }
        }
        return m;
    }

}