org.springframework.core.io.ByteArrayResource Maven / Gradle / Ivy
/*
* Copyright 2002-2018 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.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Arrays;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
/**
* {@link Resource} implementation for a given byte array.
* Creates a {@link ByteArrayInputStream} for the given byte array.
*
*
Useful for loading content from any given byte array,
* without having to resort to a single-use {@link InputStreamResource}.
* Particularly useful for creating mail attachments from local content,
* where JavaMail needs to be able to read the stream multiple times.
*
* @author Juergen Hoeller
* @author Sam Brannen
* @since 1.2.3
* @see java.io.ByteArrayInputStream
* @see InputStreamResource
* @see org.springframework.mail.javamail.MimeMessageHelper#addAttachment(String, InputStreamSource)
*/
public class ByteArrayResource extends AbstractResource {
private final byte[] byteArray;
private final String description;
/**
* Create a new {@code ByteArrayResource}.
* @param byteArray the byte array to wrap
*/
public ByteArrayResource(byte[] byteArray) {
this(byteArray, "resource loaded from byte array");
}
/**
* Create a new {@code ByteArrayResource} with a description.
* @param byteArray the byte array to wrap
* @param description where the byte array comes from
*/
public ByteArrayResource(byte[] byteArray, @Nullable String description) {
Assert.notNull(byteArray, "Byte array must not be null");
this.byteArray = byteArray;
this.description = (description != null ? description : "");
}
/**
* Return the underlying byte array.
*/
public final byte[] getByteArray() {
return this.byteArray;
}
/**
* This implementation always returns {@code true}.
*/
@Override
public boolean exists() {
return true;
}
/**
* This implementation returns the length of the underlying byte array.
*/
@Override
public long contentLength() {
return this.byteArray.length;
}
/**
* This implementation returns a ByteArrayInputStream for the
* underlying byte array.
* @see java.io.ByteArrayInputStream
*/
@Override
public InputStream getInputStream() throws IOException {
return new ByteArrayInputStream(this.byteArray);
}
/**
* This implementation returns a description that includes the passed-in
* {@code description}, if any.
*/
@Override
public String getDescription() {
return "Byte array resource [" + this.description + "]";
}
/**
* This implementation compares the underlying byte array.
* @see java.util.Arrays#equals(byte[], byte[])
*/
@Override
public boolean equals(@Nullable Object other) {
return (this == other || (other instanceof ByteArrayResource &&
Arrays.equals(((ByteArrayResource) other).byteArray, this.byteArray)));
}
/**
* This implementation returns the hash code based on the
* underlying byte array.
*/
@Override
public int hashCode() {
return (byte[].class.hashCode() * 29 * this.byteArray.length);
}
}