Package org.dellroad.stuff.vaadin24.util

Class VaadinUtil

java.lang.Object

org.dellroad.stuff.vaadin24.util.VaadinUtil

public final class VaadinUtil
extends Object

Miscellaneous utility methods.

Method Summary

Modifier and Type	Method	Description
static void	accessCurrentSession(Runnable action)	Invoke accessSession() using the VaadinSession associated with the current thread.
static void	accessSession(VaadinSession session, Runnable action)	Invoke VaadinSession.access().
static void	accessSessionSynchronously(VaadinSession session, Runnable action)	Invoke VaadinSession.accessSynchronously().
static boolean	accessUI(UI ui, Runnable action)	Invoke UI.access() but catch and discard any thrown UIDetachedException's.
static boolean	accessUI(Runnable action)	Invoke accessUI() using the UI associated with the current thread, but catch and discard any thrown UIDetachedException's.
static boolean	accessUISynchronously(UI ui, Runnable action)	Invoke UI.accessSynchronously() but catch and discard any thrown UIDetachedException's.
static void	assertCurrentSession()	Verify that there is a current and locked VaadinSession associated with the current thread.
static void	assertCurrentSession(VaadinSession session)	Verify that we are running in the context of the given session and holding the session's lock.
static void	assertNoSession()	Verify that there is no current and locked VaadinSession associated with the current thread.
static void	assertNotSession(VaadinSession session)	Verify that a VaadinSession is not associated with the current thread and locked.
static Page	getCurrentPage()	Get the Page associated with the current UI.
static VaadinRequest	getCurrentRequest()	Get the VaadinRequest associated with the current thread and require that it be found.
static VaadinSession	getCurrentSession()	Get the VaadinSession associated with the current thread and require that it be found and locked.
static UI	getCurrentUI()	Get the UI associated with the current thread and require that it be found.

Methods inherited from class java.lang.Object

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

Method Details

assertCurrentSession

public static void assertCurrentSession()

Verify that there is a current and locked VaadinSession associated with the current thread.

This method is equivalent to getCurrentSession() but doesn't actually return the session.

Throws:

IllegalStateException - if there is no VaadinSession associated with the current thread

IllegalStateException - if the VaadinSession associated with the current thread is not locked

assertCurrentSession

public static void assertCurrentSession(VaadinSession session)

Verify that we are running in the context of the given session and holding the session's lock.

This method can be used by any code that manipulates Vaadin state to assert that the proper Vaadin locking has been performed on the expected session.

Parameters:

session - session we are supposed to be running with

Throws:

IllegalArgumentException - if session is null

IllegalStateException - if there is no VaadinSession associated with the current thread

IllegalStateException - if the VaadinSession associated with the current thread is not session

IllegalStateException - if the VaadinSession associated with the current thread is not locked

getCurrentSession

public static VaadinSession getCurrentSession()

Get the VaadinSession associated with the current thread and require that it be found and locked.

This is a wrapper around VaadinSession.getCurrent() that (a) throws an exception instead of returning null when there is no session associated with the current thread and (b) verifies the session is locked.

Returns:

current VaadinSession, never null

Throws:

IllegalStateException - if there is no VaadinSession associated with the current thread

IllegalStateException - if the VaadinSession associated with the current thread is not locked

accessCurrentSession

public static void accessCurrentSession(Runnable action)

Invoke accessSession() using the VaadinSession associated with the current thread.

Parameters:

action - action to perform

Throws:

IllegalArgumentException - if action is null

IllegalStateException - if there is no VaadinSession associated with the current thread

IllegalStateException - if the VaadinSession associated with the current thread is not locked

accessSession

public static void accessSession(VaadinSession session,
 Runnable action)

Invoke VaadinSession.access().

Parameters:

session - the session to access

action - action to perform

Throws:

IllegalArgumentException - if session or action is null

accessSessionSynchronously

public static void accessSessionSynchronously(VaadinSession session,
 Runnable action)

Invoke VaadinSession.accessSynchronously().

Parameters:

session - the session to access, or null

action - action to perform

Throws:

IllegalArgumentException - if session is null

IllegalArgumentException - if action is null

assertNoSession

public static void assertNoSession()

Verify that there is no current and locked VaadinSession associated with the current thread.

Throws:

IllegalStateException - if there is a current and locked Vaadin session associated with the current thread

assertNotSession

public static void assertNotSession(VaadinSession session)

Verify that a VaadinSession is not associated with the current thread and locked.

To verify this only for one specific VaadinSession, pass that VaadinSession as the parameter.

To verify this for any VaadinSession whatsoever, pass null as the parameter.

Parameters:

session - some VaadinSession, or null for any VaadinSession

Throws:

IllegalStateException - if a/the VaadinSession associated with the current thread and locked by it

getCurrentRequest

public static VaadinRequest getCurrentRequest()

Get the VaadinRequest associated with the current thread and require that it be found.

This is just a wrapper around VaadinRequest.getCurrent() that throws an exception instead of returning null when there is no request associated with the current thread.

Returns:

current VaadinRequest, never null

Throws:

IllegalStateException - if there is no VaadinRequest associated with the current thread

getCurrentUI

public static UI getCurrentUI()

Get the UI associated with the current thread and require that it be found.

This is just a wrapper around UI.getCurrent() that throws an exception instead of returning null when there is no request associated with the current thread.

Returns:

current UI, never null

Throws:

IllegalStateException - if there is no UI associated with the current thread

accessUI

public static boolean accessUI(Runnable action)

Invoke accessUI() using the UI associated with the current thread, but catch and discard any thrown UIDetachedException's.

Does nothing (and returns false) if the current UI is not attached.

Parameters:

action - action to perform

Returns:

true if successfully invoked, false if the current UI is detached

Throws:

IllegalArgumentException - if action is null

IllegalStateException - if there is no UI associated with the current thread

accessUI

public static boolean accessUI(UI ui,
 Runnable action)

Invoke UI.access() but catch and discard any thrown UIDetachedException's.

Does nothing (and returns false) if ui is null or not attached.

Parameters:

ui - the UI to access, or null

action - action to perform

Returns:

true if successfully invoked, false if ui is null or detached

Throws:

IllegalArgumentException - if action is null

accessUISynchronously

public static boolean accessUISynchronously(UI ui,
 Runnable action)

Invoke UI.accessSynchronously() but catch and discard any thrown UIDetachedException's.

Does nothing (and returns false) if ui is null or not attached to a VaadinSession.

Parameters:

ui - the UI to access, or null

action - action to perform

Returns:

true if successfully invoked, otherwise false

Throws:

IllegalArgumentException - if action is null

getCurrentPage

public static Page getCurrentPage()

Get the Page associated with the current UI.

Returns:

current Page, never null

Throws:

IllegalStateException - if there is no UI associated with the current thread

IllegalStateException - if there is no Page associated with the UI associated with the current thread