/*
* Copyright 2014 mango.jfaster.org
*
* The Mango Project licenses this file to you under the Apache License,
* version 2.0 (the "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License 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 org.jfaster.mango.invoker.function;
import org.jfaster.mango.invoker.GetterFunction;
import javax.annotation.Nullable;
import java.util.List;
/**
* List<String> --> String
*
* @author ash
*/
public class StringListToStringFunction implements GetterFunction<List<String>, String> {
private final static String SEPARATOR = ",";
@Nullable
@Override
public String apply(@Nullable List<String> input) {
if (input == null) {
return null;
}
if (input.size() == 0) {
return "";
}
StringBuilder builder = new StringBuilder();
builder.append(input.get(0));
for (int i = 1; i < input.size(); i++) {
builder.append(SEPARATOR).append(input.get(i));
}
return builder.toString();
}
}