001// Copyright 2005 The Apache Software Foundation 002// 003// Licensed under the Apache License, Version 2.0 (the "License"); 004// you may not use this file except in compliance with the License. 005// You may obtain a copy of the License at 006// 007// http://www.apache.org/licenses/LICENSE-2.0 008// 009// Unless required by applicable law or agreed to in writing, software 010// distributed under the License is distributed on an "AS IS" BASIS, 011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 012// See the License for the specific language governing permissions and 013// limitations under the License. 014 015package org.apache.tapestry.asset; 016 017/** 018 * Calculates the digest value, as a string, for a particular classpath resource. This is primarily 019 * used by the {@link org.apache.tapestry.asset.AssetService}to authenticate requests (you are not 020 * allowed access to a resource unless you can provide the correct digest value). 021 * 022 * @author Howard M. Lewis Ship 023 * @since 4.0 024 */ 025public interface ResourceDigestSource 026{ 027 /** 028 * Calculates the DIGEST checksum for a classpath resource. Because this is expensive, the value 029 * may be cached. 030 * 031 * @param resourcePath 032 * the classpath resource, which should start with a leading slash. 033 * @return A string representation of the digest for the provided resource path. 034 * @throws ApplicationRuntimeException 035 * if the resource does not exist, or there is an error calculating the checksum. 036 */ 037 038 public String getDigestForResource(String resourcePath); 039}