com.yahoo.text.MapParser Maven / Gradle / Ivy
// 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);
}