// =================================================================================================
// Copyright 2011 Twitter, Inc.
// -------------------------------------------------------------------------------------------------
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this work except in compliance with the License.
// You may obtain a copy of the License in the LICENSE file, or at:
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// =================================================================================================
package com.twitter.common.args.parsers;
import java.lang.reflect.Type;
import java.util.List;
import java.util.Map;
import com.google.common.base.Splitter;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.common.reflect.TypeToken;
import com.twitter.common.args.ArgParser;
import com.twitter.common.args.Parser;
import com.twitter.common.args.ParserOracle;
import com.twitter.common.args.Parsers;
import static com.google.common.base.Preconditions.checkArgument;
/**
* Map parser.
*
* @author William Farner
*/
@ArgParser
public class MapParser extends TypeParameterizedParser<Map<?, ?>> {
private static final Splitter KEY_VALUE_SPLITTER =
Splitter.on("=").trimResults().omitEmptyStrings();
public MapParser() {
super(2);
}
@SuppressWarnings("unchecked")
@Override
Map<?, ?> doParse(ParserOracle parserOracle, String raw, List<Type> typeParams) {
Type keyType = typeParams.get(0);
Parser<?> keyParser = parserOracle.get(TypeToken.of(keyType));
Type valueType = typeParams.get(1);
Parser<?> valueParser = parserOracle.get(TypeToken.of(valueType));
ImmutableMap.Builder<Object, Object> map = ImmutableMap.builder();
for (String keyAndValue : Parsers.MULTI_VALUE_SPLITTER.split(raw)) {
List<String> fields = ImmutableList.copyOf(KEY_VALUE_SPLITTER.split(keyAndValue));
checkArgument(fields.size() == 2,
"Failed to parse key/value pair " + keyAndValue);
map.put(keyParser.parse(parserOracle, keyType, fields.get(0)),
valueParser.parse(parserOracle, valueType, fields.get(1)));
}
return map.build();
}
}