com.vaadin.server.StreamResource Maven / Gradle / Ivy
/*
* Copyright (C) 2000-2024 Vaadin Ltd
*
* This program is available under Vaadin Commercial License and Service Terms.
*
* See for the full
* license.
*/
package com.vaadin.server;
import java.io.InputStream;
import java.io.Serializable;
import java.util.Arrays;
import com.vaadin.shared.util.SharedUtil;
import com.vaadin.util.FileTypeResolver;
/**
* StreamResource is a resource provided to the client directly by
* the application.
*
* @author Vaadin Ltd.
* @since 3.0
*/
@SuppressWarnings("serial")
public class StreamResource implements ConnectorResource {
/**
* Source stream the downloaded content is fetched from.
*/
private StreamSource streamSource = null;
/**
* Explicit mime-type.
*/
private String mimeType = null;
/**
* Filename.
*/
private String filename;
/**
* Default buffer size for this stream resource.
*/
private int bufferSize = 0;
/**
* Default cache time for this stream resource.
*/
private long cacheTime = DownloadStream.DEFAULT_CACHETIME;
/**
* Creates a new stream resource for downloading from stream.
*
* @param streamSource
* the source Stream.
* @param filename
* the name of the file.
*/
public StreamResource(StreamSource streamSource, String filename) {
setFilename(filename);
setStreamSource(streamSource);
}
/**
* @see com.vaadin.server.Resource#getMIMEType()
*/
@Override
public String getMIMEType() {
if (mimeType != null) {
return mimeType;
}
return FileTypeResolver.getMIMEType(filename);
}
/**
* Sets the mime type of the resource.
*
* @param mimeType
* the MIME type to be set.
*/
public void setMIMEType(String mimeType) {
this.mimeType = mimeType;
}
/**
* Returns the source for this StreamResource. StreamSource is
* queried when the resource is about to be streamed to the client.
*
* @return Source of the StreamResource.
*/
public StreamSource getStreamSource() {
return streamSource;
}
/**
* Sets the source for this StreamResource.
* StreamSource is queried when the resource is about to be
* streamed to the client.
*
* @param streamSource
* the source to set.
*/
public void setStreamSource(StreamSource streamSource) {
this.streamSource = streamSource;
}
/**
* Gets the filename.
*
* @return the filename.
*/
@Override
public String getFilename() {
return filename;
}
/**
* Sets the filename.
*
* @param filename
* the filename to set.
*/
public void setFilename(String filename) {
this.filename = filename;
}
@Override
public DownloadStream getStream() {
final StreamSource ss = getStreamSource();
if (ss == null) {
return null;
}
final DownloadStream ds = new DownloadStream(ss.getStream(),
getMIMEType(), getFilename());
ds.setBufferSize(getBufferSize());
ds.setCacheTime(getCacheTime());
return ds;
}
/**
* Interface implemented by the source of a StreamResource.
*
* @author Vaadin Ltd.
* @since 3.0
*/
@FunctionalInterface
public interface StreamSource extends Serializable {
/**
* Returns new input stream that is used for reading the resource.
*/
public InputStream getStream();
}
/**
* Gets the size of the download buffer used for this resource.
*
*
* If the buffer size is 0, the buffer size is decided by the terminal
* adapter. The default value is 0.
*
*
* @return the size of the buffer in bytes.
*/
public int getBufferSize() {
return bufferSize;
}
/**
* Sets the size of the download buffer used for this resource.
*
* @param bufferSize
* the size of the buffer in bytes.
*/
public void setBufferSize(int bufferSize) {
this.bufferSize = bufferSize;
}
/**
* Gets the length of cache expiration time. This gives the adapter the
* possibility cache streams sent to the client. The caching may be made in
* adapter or at the client if the client supports caching. Default is
* DownloadStream.DEFAULT_CACHETIME.
*
* @return Cache time in milliseconds.
*/
public long getCacheTime() {
return cacheTime;
}
/**
* Sets the length of cache expiration time.
*
*
* This gives the adapter the possibility cache streams sent to the client.
* The caching may be made in adapter or at the client if the client
* supports caching. Zero or negative value disables the caching of this
* stream.
*
*
* @param cacheTime
* the cache time in milliseconds.
*
*/
public void setCacheTime(long cacheTime) {
this.cacheTime = cacheTime;
}
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
} else if (obj instanceof StreamResource) {
StreamResource that = (StreamResource) obj;
return SharedUtil.equals(getStreamSource(), that.getStreamSource())
&& SharedUtil.equals(mimeType, that.mimeType)
&& SharedUtil.equals(getFilename(), that.getFilename())
&& getBufferSize() == that.getBufferSize()
&& getCacheTime() == that.getCacheTime();
} else {
return false;
}
}
@Override
public int hashCode() {
return Arrays.hashCode(new Object[] { getStreamSource(), mimeType,
getFilename(), getBufferSize(), getCacheTime() });
}
}