org.springframework.core.io.WritableResource.java Source code

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Here is the source code for org.springframework.core.io.WritableResource.java

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/*
 * Copyright 2002-2017 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * 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.
 */

package org.springframework.core.io;

import java.io.IOException;
import java.io.OutputStream;
import java.nio.channels.Channels;
import java.nio.channels.WritableByteChannel;

/**
 * Extended interface for a resource that supports writing to it.
 * Provides an {@link #getOutputStream() OutputStream accessor}.
 *
 * @author Juergen Hoeller
 * @since 3.1
 * @see java.io.OutputStream
 */
public interface WritableResource extends Resource {

    /**
     * Indicate whether the contents of this resource can be written
     * via {@link #getOutputStream()}.
     * <p>Will be {@code true} for typical resource descriptors;
     * note that actual content writing may still fail when attempted.
     * However, a value of {@code false} is a definitive indication
     * that the resource content cannot be modified.
     * @see #getOutputStream()
     * @see #isReadable()
     */
    default boolean isWritable() {
        return true;
    }

    /**
     * Return an {@link OutputStream} for the underlying resource,
     * allowing to (over-)write its content.
     * @throws IOException if the stream could not be opened
     * @see #getInputStream()
     */
    OutputStream getOutputStream() throws IOException;

    /**
     * Return a {@link WritableByteChannel}.
     * <p>It is expected that each call creates a <i>fresh</i> channel.
     * <p>The default implementation returns {@link Channels#newChannel(OutputStream)}
     * with the result of {@link #getOutputStream()}.
     * @return the byte channel for the underlying resource (must not be {@code null})
     * @throws java.io.FileNotFoundException if the underlying resource doesn't exist
     * @throws IOException if the content channel could not be opened
     * @since 5.0
     * @see #getOutputStream()
     */
    default WritableByteChannel writableChannel() throws IOException {
        return Channels.newChannel(getOutputStream());
    }

}