com.vaadin.server.ClassResource 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 com.vaadin.ui.LegacyWindow;
import com.vaadin.ui.UI;
import com.vaadin.util.FileTypeResolver;
/**
* ClassResource is a named resource accessed with the class
* loader.
*
* This can be used to access resources such as icons, files, etc.
*
* @see java.lang.Class#getResource(java.lang.String)
*
* @author Vaadin Ltd.
* @since 3.0
*/
@SuppressWarnings("serial")
public class ClassResource implements ConnectorResource {
/**
* Default buffer size for this stream resource.
*/
private int bufferSize = 0;
/**
* Default cache time for this stream resource.
*/
private long cacheTime = DownloadStream.DEFAULT_CACHETIME;
/**
* Associated class used for identifying the source of the resource.
*/
private final Class associatedClass;
/**
* Name of the resource is relative to the associated class.
*/
private final String resourceName;
/**
* Creates a new application resource instance. The resource id is relative
* to the location of the UI of the component using this resource (or the
* Application if using LegacyWindow).
*
* @param resourceName
* the Unique identifier of the resource within the application.
*/
public ClassResource(String resourceName) {
this(null, resourceName);
}
/**
* Creates a new application resource instance.
*
* @param associatedClass
* the class of the which the resource is associated.
* @param resourceName
* the Unique identifier of the resource within the application.
*/
public ClassResource(Class associatedClass, String resourceName) {
this.associatedClass = associatedClass;
this.resourceName = resourceName;
if (resourceName == null) {
throw new NullPointerException();
}
}
/**
* Gets the MIME type of this resource.
*
* @see com.vaadin.server.Resource#getMIMEType()
*/
@Override
public String getMIMEType() {
return FileTypeResolver.getMIMEType(resourceName);
}
@Override
public String getFilename() {
String[] parts = resourceName.split("/");
return parts[parts.length - 1];
}
@Override
public DownloadStream getStream() {
final DownloadStream ds = new DownloadStream(
getAssociatedClass().getResourceAsStream(resourceName),
getMIMEType(), getFilename());
ds.setBufferSize(getBufferSize());
ds.setCacheTime(getCacheTime());
return ds;
}
protected Class getAssociatedClass() {
if (associatedClass == null) {
UI current = UI.getCurrent();
if (current instanceof LegacyWindow) {
LegacyWindow legacyWindow = (LegacyWindow) current;
return legacyWindow.getApplication().getClass();
} else {
return current.getClass();
}
}
return associatedClass;
}
/**
* 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.
*
* @see #getBufferSize()
*/
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 {@link 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;
}
}