Here you can find the source of setValue(java.util.Map
public static void setValue(java.util.Map<QName, String> map, String name, String newValue)
//package com.java2s; /*//from w w w . j ava 2 s . co m * Copyright (C) 2015 The 8-Bit Bunch. Licensed under the Apache License, Version 1.1 * (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-1.1>. * 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.util.Optional; import javax.xml.namespace.QName; public class Main { public static void setValue(java.util.Map<QName, String> map, String name, String newValue) { Optional<java.util.Map.Entry<QName, String>> attr = map.entrySet().stream() .filter((e) -> e.getKey().getLocalPart().equals(name)).findFirst(); if (attr.isPresent()) { attr.get().setValue(newValue); } else { map.put(new QName(name), newValue); } } }