001/* 002 * Copyright 2002-2017 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.IOException; 020import java.io.OutputStream; 021import java.nio.channels.Channels; 022import java.nio.channels.WritableByteChannel; 023 024/** 025 * Extended interface for a resource that supports writing to it. 026 * Provides an {@link #getOutputStream() OutputStream accessor}. 027 * 028 * @author Juergen Hoeller 029 * @since 3.1 030 * @see java.io.OutputStream 031 */ 032public interface WritableResource extends Resource { 033 034 /** 035 * Indicate whether the contents of this resource can be written 036 * via {@link #getOutputStream()}. 037 * <p>Will be {@code true} for typical resource descriptors; 038 * note that actual content writing may still fail when attempted. 039 * However, a value of {@code false} is a definitive indication 040 * that the resource content cannot be modified. 041 * @see #getOutputStream() 042 * @see #isReadable() 043 */ 044 default boolean isWritable() { 045 return true; 046 } 047 048 /** 049 * Return an {@link OutputStream} for the underlying resource, 050 * allowing to (over-)write its content. 051 * @throws IOException if the stream could not be opened 052 * @see #getInputStream() 053 */ 054 OutputStream getOutputStream() throws IOException; 055 056 /** 057 * Return a {@link WritableByteChannel}. 058 * <p>It is expected that each call creates a <i>fresh</i> channel. 059 * <p>The default implementation returns {@link Channels#newChannel(OutputStream)} 060 * with the result of {@link #getOutputStream()}. 061 * @return the byte channel for the underlying resource (must not be {@code null}) 062 * @throws java.io.FileNotFoundException if the underlying resource doesn't exist 063 * @throws IOException if the content channel could not be opened 064 * @since 5.0 065 * @see #getOutputStream() 066 */ 067 default WritableByteChannel writableChannel() throws IOException { 068 return Channels.newChannel(getOutputStream()); 069 } 070 071}