Portlet API (V1.0)

javax.portlet
Interface RenderResponse

All Superinterfaces:
PortletResponse

public interface RenderResponse
extends PortletResponse

The RenderResponse defines an object to assist a portlet in sending a response to the portal. It extends the PortletResponse interface to provide specific render response functionality to portlets.
The portlet container creates a RenderResponse object and passes it as argument to the portlet's render method.

See Also:
RenderRequest, PortletResponse

Field Summary
static java.lang.String EXPIRATION_CACHE
          Property to set the expiration time in seconds for this response using the setProperty method.
 
Method Summary
 PortletURL createActionURL()
          Creates a portlet URL targeting the portlet.
 PortletURL createRenderURL()
          Creates a portlet URL targeting the portlet.
 void flushBuffer()
          Forces any content in the buffer to be written to the client.
 int getBufferSize()
          Returns the actual buffer size used for the response.
 java.lang.String getCharacterEncoding()
          Returns the name of the charset used for the MIME body sent in this response.
 java.lang.String getContentType()
          Returns the MIME type that can be used to contribute markup to the render response.
 java.util.Locale getLocale()
          Returns the locale assigned to the response.
 java.lang.String getNamespace()
          The value returned by this method should be prefixed or appended to elements, such as JavaScript variables or function names, to ensure they are unique in the context of the portal page.
 java.io.OutputStream getPortletOutputStream()
          Returns a OutputStream suitable for writing binary data in the response.
 java.io.PrintWriter getWriter()
          Returns a PrintWriter object that can send character text to the portal.
 boolean isCommitted()
          Returns a boolean indicating if the response has been committed.
 void reset()
          Clears any data that exists in the buffer as well as the properties set.
 void resetBuffer()
          Clears the content of the underlying buffer in the response without clearing properties set.
 void setBufferSize(int size)
          Sets the preferred buffer size for the body of the response.
 void setContentType(java.lang.String type)
          Sets the MIME type for the render response.
 void setTitle(java.lang.String title)
          This method sets the title of the portlet.
 
Methods inherited from interface javax.portlet.PortletResponse
addProperty, encodeURL, setProperty
 

Field Detail

EXPIRATION_CACHE

public static final java.lang.String EXPIRATION_CACHE
Property to set the expiration time in seconds for this response using the setProperty method.

If the expiration value is set to 0, caching is disabled for this portlet; if the value is set to -1, the cache does not expire.

The value is "portlet.expiration-cache".

Method Detail

getContentType

public java.lang.String getContentType()
Returns the MIME type that can be used to contribute markup to the render response.

If no content type was set previously using the setContentType(java.lang.String) method this method retuns null.

Returns:
the MIME type of the response, or null if no content type is set
See Also:
setContentType(java.lang.String)

createRenderURL

public PortletURL createRenderURL()
Creates a portlet URL targeting the portlet. If no portlet mode, window state or security modifier is set in the PortletURL the current values are preserved. If a request is triggered by the PortletURL, it results in a render request.

The returned URL can be further extended by adding portlet-specific parameters and portlet modes and window states.

The created URL will per default not contain any parameters of the current render request.

Returns:
a portlet render URL

createActionURL

public PortletURL createActionURL()
Creates a portlet URL targeting the portlet. If no portlet mode, window state or security modifier is set in the PortletURL the current values are preserved. If a request is triggered by the PortletURL, it results in an action request.

The returned URL can be further extended by adding portlet-specific parameters and portlet modes and window states.

The created URL will per default not contain any parameters of the current render request.

Returns:
a portlet action URL

getNamespace

public java.lang.String getNamespace()
The value returned by this method should be prefixed or appended to elements, such as JavaScript variables or function names, to ensure they are unique in the context of the portal page.
Returns:
the namespace

setTitle

public void setTitle(java.lang.String title)
This method sets the title of the portlet.

The value can be a text String

Parameters:
title - portlet title as text String or resource URI

setContentType

public void setContentType(java.lang.String type)
Sets the MIME type for the render response. The portlet must set the content type before calling getWriter() or getPortletOutputStream().

Calling setContentType after getWriter or getOutputStream does not change the content type.

Parameters:
type - the content MIME type
Throws:
java.lang.IllegalArgumentException - if the given type is not in the list returned by PortletRequest.getResponseContentTypes
See Also:
PortletRequest.getResponseContentTypes(), getContentType()

getCharacterEncoding

public java.lang.String getCharacterEncoding()
Returns the name of the charset used for the MIME body sent in this response.

See RFC 2047 for more information about character encoding and MIME.

Returns:
a String specifying the name of the charset, for example, ISO-8859-1

getWriter

public java.io.PrintWriter getWriter()
                              throws java.io.IOException
Returns a PrintWriter object that can send character text to the portal.

Before calling this method the content type of the render response must be set using the setContentType(java.lang.String) method.

Either this method or getPortletOutputStream() may be called to write the body, not both.

Returns:
a PrintWriter object that can return character data to the portal
Throws:
java.io.IOException - if an input or output exception occurred
java.lang.IllegalStateException - if the getPortletOutputStream method has been called on this response, or if no content type was set using the setContentType method.
See Also:
setContentType(java.lang.String), getPortletOutputStream()

getLocale

public java.util.Locale getLocale()
Returns the locale assigned to the response.
Returns:
Locale of this response

setBufferSize

public void setBufferSize(int size)
Sets the preferred buffer size for the body of the response. The portlet container will use a buffer at least as large as the size requested.

This method must be called before any response body content is written; if content has been written, or the portlet container does not support buffering, this method may throw an IllegalStateException.

Parameters:
size - the preferred buffer size
Throws:
java.lang.IllegalStateException - if this method is called after content has been written, or the portlet container does not support buffering
See Also:
getBufferSize(), flushBuffer(), isCommitted(), reset()

getBufferSize

public int getBufferSize()
Returns the actual buffer size used for the response. If no buffering is used, this method returns 0.
Returns:
the actual buffer size used
See Also:
setBufferSize(int), flushBuffer(), isCommitted(), reset()

flushBuffer

public void flushBuffer()
                 throws java.io.IOException
Forces any content in the buffer to be written to the client. A call to this method automatically commits the response.
Throws:
java.io.IOException - if an error occured when writing the output
See Also:
setBufferSize(int), getBufferSize(), isCommitted(), reset()

resetBuffer

public void resetBuffer()
Clears the content of the underlying buffer in the response without clearing properties set. If the response has been committed, this method throws an IllegalStateException.
Throws:
IllegalStateException - if this method is called after response is comitted
See Also:
setBufferSize(int), getBufferSize(), isCommitted(), reset()

isCommitted

public boolean isCommitted()
Returns a boolean indicating if the response has been committed.
Returns:
a boolean indicating if the response has been committed
See Also:
setBufferSize(int), getBufferSize(), flushBuffer(), reset()

reset

public void reset()
Clears any data that exists in the buffer as well as the properties set. If the response has been committed, this method throws an IllegalStateException.
Throws:
java.lang.IllegalStateException - if the response has already been committed
See Also:
setBufferSize(int), getBufferSize(), flushBuffer(), isCommitted()

getPortletOutputStream

public java.io.OutputStream getPortletOutputStream()
                                            throws java.io.IOException
Returns a OutputStream suitable for writing binary data in the response. The portlet container does not encode the binary data.

Before calling this method the content type of the render response must be set using the setContentType(java.lang.String) method.

Calling flush() on the OutputStream commits the response.

Either this method or getWriter() may be called to write the body, not both.

Returns:
a OutputStream for writing binary data
Throws:
java.lang.IllegalStateException - if the getWriter method has been called on this response, or if no content type was set using the setContentType method.
java.io.IOException - if an input or output exception occurred
See Also:
setContentType(java.lang.String), getWriter()

Portlet API (V1.0)

Copyright © 2003 IBM Corporation and Sun Microsystems, Inc. All rights reserved