001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.commons.fileupload2.core; 018 019/** 020 * Receives progress information. May be used to display a progress bar. 021 */ 022@FunctionalInterface 023public interface ProgressListener { 024 025 /** 026 * Nop implementation. 027 */ 028 ProgressListener NOP = (bytesRead, contentLength, items) -> { 029 // nop 030 }; 031 032 /** 033 * Updates the listeners status information. 034 * 035 * @param bytesRead The total number of bytes, which have been read so far. 036 * @param contentLength The total number of bytes, which are being read. May be -1, if this number is unknown. 037 * @param items The number of the field, which is currently being read. (0 = no item so far, 1 = first item is being read, ...) 038 */ 039 void update(long bytesRead, long contentLength, int items); 040 041}