Here you can find the source of toStringSet(Collection
public static Set<String> toStringSet(Collection<URI> uris)
//package com.java2s; /*//from www .j a v a 2 s. c o m * Copyright 2015 Texas A&M Engineering Experiment Station * * Licensed 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. */ import java.net.URI; import java.util.Collection; import java.util.HashSet; import java.util.Set; public class Main { public static Set<String> toStringSet(Collection<URI> uris) { Set<String> result = new HashSet<String>(); for (URI uri : uris) { result.add(uri.toASCIIString()); } return result; } }