org.springframework.core.io.InputStreamResource Maven / Gradle / Ivy
/*
* Copyright 2002-2004 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 org.springframework.core.io;
import java.io.IOException;
import java.io.InputStream;
/**
* Resource implementation for a given InputStream. Should only
* be used if no specific Resource implementation is applicable.
*
* In contrast to other Resource implementations, this is a descriptor
* for an already opened resource - therefore returning true on
* isOpen(). Do not use it if you need to keep the resource descriptor
* somewhere, or if you need to read a stream multiple times.
*
* @author Juergen Hoeller
* @since 28.12.2003
*/
public class InputStreamResource extends AbstractResource {
private InputStream inputStream;
private final String description;
/**
* Create a new InputStreamResource.
* @param inputStream the InputStream to use
*/
public InputStreamResource(InputStream inputStream) {
this(inputStream, "resource loaded through InputStream");
}
/**
* Create a new InputStreamResource.
* @param inputStream the InputStream to use
* @param description where the InputStream comes from
*/
public InputStreamResource(InputStream inputStream, String description) {
if (inputStream == null) {
throw new IllegalArgumentException("InputStream must not be null");
}
this.inputStream = inputStream;
this.description = description;
}
public boolean exists() {
return true;
}
public boolean isOpen() {
return true;
}
/**
* This implementation throws IllegalStateException if attempting to
* read the underlying stream multiple times.
*/
public InputStream getInputStream() throws IOException, IllegalStateException {
if (this.inputStream == null) {
throw new IllegalStateException("InputStream has already been read - " +
"do not use InputStreamResource if a stream needs to be read multiple times");
}
InputStream result = this.inputStream;
this.inputStream = null;
return result;
}
public String getDescription() {
return description;
}
}