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Library for use in Java components of Vespa. Shared code which do not fit anywhere else.

There is a newer version: 8.441.21

// Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
package com.yahoo.text;

import java.util.HashMap;
import java.util.Map;

/**
 * Superclasses of parsers of a map represented textually as
 * {key1:value1,"anystringkey":value2,'anystringkey2':value3 ...}.
 * This parser must be extended to override the way values are parsed and constructed.
 *
 * Example: To create a Double map parser:
 *  * public static final class DoubleMapParser extends MapParser<Double> {
 *
 *     @Override
 *     protected Double parseValue(String value) {
 *         return Double.parseDouble(value);
 *     }
 *
 * }
 * 
 *
 * Map parsers are NOT multithread safe, but are cheap to construct.
 *
 * @author bratseth
 */
public abstract class MapParser extends SimpleMapParser {

    private Map map;

    /**
     * Convenience method doing return parse(s,new HashMap<String,VALUETYPE>())
     */
    public Map parseToMap(String s) {
        return parse(s,new HashMap<>());
    }

    /**
     * Parses a map on the form {key1:value1,key2:value2 ...}
     *
     * @param string the textual representation of the map
     * @param map the map to which the values will be added
     * @return the input map instance for convenience
     */
    public Map parse(String string,Map map) {
        this.map = map;
        parse(string);
        return this.map;
    }

    protected void handleKeyValue(String key, String value) {
        map.put(key, parseValue(value));
    }

    protected abstract VALUETYPE parseValue(String value);

}