com.wl4g.component.common.resource.ByteArrayStreamResource Maven / Gradle / Ivy
/*
* Copyright 2017 ~ 2025 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
*
* http://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 com.wl4g.component.common.resource;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Arrays;
import com.wl4g.component.common.lang.Assert2;
/**
* {@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.
*
* @see java.io.ByteArrayInputStream
* @see InputStreamResource
*/
public class ByteArrayStreamResource extends AbstractStreamResource {
final private byte[] byteArray;
final private String description;
/**
* Create a new {@code ByteArrayStreamResource}.
*
* @param byteArray
* the byte array to wrap
*/
public ByteArrayStreamResource(byte[] byteArray) {
this(byteArray, "resource loaded from byte array");
}
/**
* Create a new {@code ByteArrayStreamResource} with a description.
*
* @param byteArray
* the byte array to wrap
* @param description
* where the byte array comes from
*/
public ByteArrayStreamResource(byte[] byteArray, String description) {
Assert2.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(Object obj) {
return (obj == this || (obj instanceof ByteArrayStreamResource
&& Arrays.equals(((ByteArrayStreamResource) obj).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);
}
}