com.vaadin.server.communication.

java.lang.Object
- com.vaadin.server.SynchronizedRequestHandler
- - com.vaadin.server.communication.UidlRequestHandler

All Implemented Interfaces:

RequestHandler, SessionExpiredHandler, Serializable
```
public class UidlRequestHandler
extends SynchronizedRequestHandler
implements SessionExpiredHandler
```
Processes a UIDL request from the client. Uses ServerRpcHandler to execute client-to-server RPC invocations and UidlWriter to write state changes and client RPC calls back to the client.

Since:

7.1

Author:

Vaadin Ltd

See Also:

Serialized Form

Nested Class Summary
- Nested classes/interfaces inherited from class com.vaadin.server.SynchronizedRequestHandler
  SynchronizedRequestHandler.ResponseWriter

Field Summary

Fields
Modifier and Type Field Description

static String UIDL_PATH
- Fields inherited from class com.vaadin.server.SynchronizedRequestHandler
  MAX_BUFFER_SIZE

Constructor Summary

Constructors
Constructor Description

UidlRequestHandler()

Method Summary

All Methods
Modifier and Type	Method	Description
`protected boolean`	`canHandleRequest(VaadinRequest request)`	Check whether a request may be handled by this handler.
`protected void`	`closeJsonMessage(Writer outWriter)`
`protected ServerRpcHandler`	`createRpcHandler()`	Creates the ServerRpcHandler to use.
`boolean`	`handleSessionExpired(VaadinRequest request, VaadinResponse response)`	Called when the a session expiration has occurred and a notification needs to be sent to the user.
`boolean`	`isReadAndWriteOutsideSessionLock()`	Returns whether request body should be read and the response written without holding `VaadinSession` lock.
`protected void`	`openJsonMessage(Writer outWriter, VaadinResponse response)`	Writes the opening of JSON message to be sent to client.
`boolean`	`synchronizedHandleRequest(VaadinSession session, VaadinRequest request, VaadinResponse response)`	Identical to `SynchronizedRequestHandler.handleRequest(VaadinSession, VaadinRequest, VaadinResponse)` except the `VaadinSession` is locked before this is called and unlocked after this has completed.
`Optional<SynchronizedRequestHandler.ResponseWriter>`	`synchronizedHandleRequest(VaadinSession session, VaadinRequest request, VaadinResponse response, String requestBody)`	Identical to `SynchronizedRequestHandler.synchronizedHandleRequest(VaadinSession, VaadinRequest, VaadinResponse)` except the `VaadinSession` is locked before this is called and the response requestBody has been read before locking the session and is provided as a separate parameter.

Methods inherited from class com.vaadin.server.SynchronizedRequestHandler
getRequestBody, handleRequest

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface com.vaadin.server.RequestHandler
handleRequest

- Field Detail
  - UIDL_PATH
```
public static final String UIDL_PATH
```
    See Also:
    
    Constant Field Values
- Constructor Detail
  - UidlRequestHandler
```
public UidlRequestHandler()
```
- Method Detail
  - createRpcHandler
```
protected ServerRpcHandler createRpcHandler()
```
    Creates the ServerRpcHandler to use.
    
    Returns:
    
    the ServerRpcHandler to use
    
    Since:
    
    7.7
  - canHandleRequest
```
protected boolean canHandleRequest(VaadinRequest request)
```
    Description copied from class: SynchronizedRequestHandler
    
    Check whether a request may be handled by this handler. This can be used as an optimization to avoid locking the session just to investigate some method property. The default implementation just returns true which means that all requests will be handled by calling SynchronizedRequestHandler.synchronizedHandleRequest(VaadinSession, VaadinRequest, VaadinResponse) with the session locked.
    
    Overrides:
    
    canHandleRequest in class SynchronizedRequestHandler
    
    Parameters:
    
    request - the request to handle
    
    Returns:
    
    true if the request handling should continue once the session has been locked; false if there's no need to lock the session since the request would still not be handled.
  - synchronizedHandleRequest
```
public boolean synchronizedHandleRequest(VaadinSession session,
                                         VaadinRequest request,
                                         VaadinResponse response)
                                  throws IOException
```
    Description copied from class: SynchronizedRequestHandler
    
    Identical to SynchronizedRequestHandler.handleRequest(VaadinSession, VaadinRequest, VaadinResponse) except the VaadinSession is locked before this is called and unlocked after this has completed.
    
    Specified by:
    
    synchronizedHandleRequest in class SynchronizedRequestHandler
    
    Parameters:
    
    session - The session for the request
    
    request - The request to handle
    
    response - The response object to which a response can be written.
    
    Returns:
    
    true if a response has been written and no further request handlers should be called, otherwise false
    
    Throws:
    
    IOException - If an IO error occurred
    
    See Also:
    
    SynchronizedRequestHandler.handleRequest(VaadinSession, VaadinRequest, VaadinResponse)
  - isReadAndWriteOutsideSessionLock
```
public boolean isReadAndWriteOutsideSessionLock()
```
    Description copied from class: SynchronizedRequestHandler
    
    Returns whether request body should be read and the response written without holding VaadinSession lock.
    
    Overrides:
    
    isReadAndWriteOutsideSessionLock in class SynchronizedRequestHandler
    
    Returns:
    
    true if SynchronizedRequestHandler.synchronizedHandleRequest(VaadinSession, VaadinRequest, VaadinResponse, String) should be called. Returns false if SynchronizedRequestHandler.synchronizedHandleRequest(VaadinSession, VaadinRequest, VaadinResponse) should be called.
  - synchronizedHandleRequest
```
public Optional<SynchronizedRequestHandler.ResponseWriter> synchronizedHandleRequest(VaadinSession session,
                                                                                     VaadinRequest request,
                                                                                     VaadinResponse response,
                                                                                     String requestBody)
                                                                              throws IOException,
                                                                                     UnsupportedOperationException
```
    Description copied from class: SynchronizedRequestHandler
    
    Identical to SynchronizedRequestHandler.synchronizedHandleRequest(VaadinSession, VaadinRequest, VaadinResponse) except the VaadinSession is locked before this is called and the response requestBody has been read before locking the session and is provided as a separate parameter.
    
    Overrides:
    
    synchronizedHandleRequest in class SynchronizedRequestHandler
    
    Parameters:
    
    session - The session for the request
    
    request - The request to handle
    
    response - The response object to which a response can be written.
    
    requestBody - Request body pre-read from the request object
    
    Returns:
    
    a ResponseWriter wrapped into an Optional, if this handler will write the response and no further request handlers should be called, otherwise an empty Optional. The ResponseWriter will be executed after the VaadinSession is unlocked.
    
    Throws:
    
    IOException - If an IO error occurred.
    
    UnsupportedOperationException
    
    See Also:
    
    SynchronizedRequestHandler.handleRequest(VaadinSession, VaadinRequest, VaadinResponse)
  - closeJsonMessage
```
protected void closeJsonMessage(Writer outWriter)
                         throws IOException
```
    Throws:
    
    IOException
  - openJsonMessage
```
protected void openJsonMessage(Writer outWriter,
                               VaadinResponse response)
                        throws IOException
```
    Writes the opening of JSON message to be sent to client.
    
    Parameters:
    
    outWriter -
    
    response -
    
    Throws:
    
    IOException
  - handleSessionExpired
```
public boolean handleSessionExpired(VaadinRequest request,
                                    VaadinResponse response)
                             throws IOException
```
    Description copied from interface: SessionExpiredHandler
    
    Called when the a session expiration has occurred and a notification needs to be sent to the user. If a response is written, this method should return true to indicate that no more SessionExpiredHandler handlers should be invoked for the request.
    
    Specified by:
    
    handleSessionExpired in interface SessionExpiredHandler
    
    Parameters:
    
    request - The request to handle
    
    response - The response object to which a response can be written.
    
    Returns:
    
    true if a response has been written and no further request handlers should be called, otherwise false
    
    Throws:
    
    IOException - If an IO error occurred

com.vaadin.server.communication.

Class UidlRequestHandler

Nested Class Summary

Nested classes/interfaces inherited from class com.vaadin.server.SynchronizedRequestHandler

Field Summary

Fields inherited from class com.vaadin.server.SynchronizedRequestHandler

Constructor Summary

Method Summary

Methods inherited from class com.vaadin.server.SynchronizedRequestHandler

Methods inherited from class java.lang.Object

Methods inherited from interface com.vaadin.server.RequestHandler

Field Detail

UIDL_PATH

Constructor Detail

UidlRequestHandler

Method Detail

createRpcHandler

canHandleRequest

synchronizedHandleRequest

isReadAndWriteOutsideSessionLock

synchronizedHandleRequest

closeJsonMessage

openJsonMessage

handleSessionExpired