Package com.vaadin.flow.server

Class StreamResource

java.lang.Object

com.vaadin.flow.server.AbstractStreamResource

com.vaadin.flow.server.StreamResource

All Implemented Interfaces:

Serializable

public class StreamResource
extends AbstractStreamResource

Represents dynamically generated data.

Resource URI registration is automatically handled by components that explicitly support stream resources and by Element.setAttribute(String, AbstractStreamResource). In other cases, the resource must manually be registered using StreamResourceRegistry.registerResource(AbstractStreamResource) to get a URI from which the browser can load the contents of the resource.

Since:

1.0

Author:

Vaadin Ltd

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor	Description
StreamResource(String name, InputStreamFactory factory)	Creates StreamResource instance using mandatory parameters name as a resource file name and input stream factory as a factory for data.
StreamResource(String name, StreamResourceWriter writer)	Creates StreamResource instance using mandatory parameters name as a resource file name and output stream writer as a data producer.

Method Summary

Modifier and Type	Method	Description
ContentTypeResolver	getContentTypeResolver()	Gets the resolver which is used to lookup the content type of the resource.
Optional<String>	getHeader(String name)	Gets the value for header name set for the resource.
Map<String,String>	getHeaders()	Gets the additionally configured headers for the resource.
String	getName()	Get the resource name.
StreamResourceWriter	getWriter()	Returns the stream resource writer.
StreamResource	setContentType(String contentType)	Set content type for the resource.
StreamResource	setContentTypeResolver(ContentTypeResolver resolver)	Sets the resolver which is used to lookup the content type of the resource.
StreamResource	setHeader(String name, String value)	Sets the value of a generic response header.

Methods inherited from class com.vaadin.flow.server.AbstractStreamResource

getCacheTime, getId, setCacheTime

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

StreamResource

public StreamResource(String name,
                      StreamResourceWriter writer)

Creates StreamResource instance using mandatory parameters name as a resource file name and output stream writer as a data producer. writer should write data in the output stream provided as an argument to its StreamResourceWriter.accept(OutputStream, VaadinSession) method.

name parameter value will be used in URI (generated when resource is registered) in a way that the name is the last segment of the path. So this is synthetic file name (not real one).

Parameters:

name - resource file name. May not be null.

writer - data output stream consumer

StreamResource

public StreamResource(String name,
                      InputStreamFactory factory)

Creates StreamResource instance using mandatory parameters name as a resource file name and input stream factory as a factory for data.

name parameter value will be used in URI (generated when resource is registered) in a way that the name is the last segment of the path. So this is synthetic file name (not real one).

Parameters:

name - resource file name. May not be null.

factory - data input stream factory. May not be null.

Method Detail

getWriter

public StreamResourceWriter getWriter()

Returns the stream resource writer.

Writer writes data in the output stream provided as an argument to its StreamResourceWriter.accept(OutputStream, VaadinSession) method.

Returns:

stream resource writer

setContentTypeResolver

public StreamResource setContentTypeResolver(ContentTypeResolver resolver)

Sets the resolver which is used to lookup the content type of the resource.

By default a resolver based on servletContext.getMimeType() is used.

Parameters:

resolver - content type resolver, not null

Returns:

this resource

setContentType

public StreamResource setContentType(String contentType)

Set content type for the resource.

This is a shorthand for setContentTypeResolver(ContentTypeResolver) with resolver which always returns contentType

Parameters:

contentType - resource content type, not null

Returns:

this resource

getContentTypeResolver

public ContentTypeResolver getContentTypeResolver()

Gets the resolver which is used to lookup the content type of the resource.

Returns:

content type resolver

setHeader

public StreamResource setHeader(String name,
                                String value)

Sets the value of a generic response header. If the header had already been set, the new value overwrites the previous one.

Parameters:

name - a header name

value - value of the header

Returns:

this resource

getHeader

public Optional<String> getHeader(String name)

Gets the value for header name set for the resource.

Parameters:

name - name of header to get value for

Returns:

an optional with header value, or an empty optional if it has not been set

getHeaders

public Map<String,String> getHeaders()

Gets the additionally configured headers for the resource.

This method doesn't return headers which are set via explicit setters like setContentType(String) and AbstractStreamResource.setCacheTime(long).

Returns:

a map of headers and their values

getName

public String getName()

Description copied from class: AbstractStreamResource

Get the resource name.

The value will be used in URI (generated when resource is registered) in a way that the name is the last segment of the path. So this is a synthetic name.

Specified by:

getName in class AbstractStreamResource

Returns:

resource name