001/* 002 * Copyright 2002-2012 the original author or authors. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * https://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package org.springframework.core.io; 018 019import java.io.FileNotFoundException; 020import java.io.IOException; 021import java.io.InputStream; 022 023/** 024 * Simple {@link Resource} implementation that holds a resource description 025 * but does not point to an actually readable resource. 026 * 027 * <p>To be used as placeholder if a {@code Resource} argument is 028 * expected by an API but not necessarily used for actual reading. 029 * 030 * @author Juergen Hoeller 031 * @since 1.2.6 032 */ 033public class DescriptiveResource extends AbstractResource { 034 035 private final String description; 036 037 038 /** 039 * Create a new DescriptiveResource. 040 * @param description the resource description 041 */ 042 public DescriptiveResource(String description) { 043 this.description = (description != null ? description : ""); 044 } 045 046 047 @Override 048 public boolean exists() { 049 return false; 050 } 051 052 @Override 053 public boolean isReadable() { 054 return false; 055 } 056 057 @Override 058 public InputStream getInputStream() throws IOException { 059 throw new FileNotFoundException( 060 getDescription() + " cannot be opened because it does not point to a readable resource"); 061 } 062 063 @Override 064 public String getDescription() { 065 return this.description; 066 } 067 068 069 /** 070 * This implementation compares the underlying description String. 071 */ 072 @Override 073 public boolean equals(Object obj) { 074 return (obj == this || 075 (obj instanceof DescriptiveResource && ((DescriptiveResource) obj).description.equals(this.description))); 076 } 077 078 /** 079 * This implementation returns the hash code of the underlying description String. 080 */ 081 @Override 082 public int hashCode() { 083 return this.description.hashCode(); 084 } 085 086}