HttpServletRequest中的getSession
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2024-02-04 14:14:28
...
- getSession(true):
如果会话存在则直接返回,否则新建会话后返回, - getSession(false):
如果会话存在则直接返回,否则返回null - getSession():
等同getSession(true)
/**
* Returns the current <code>HttpSession</code> associated with this request
* or, if there is no current session and <code>create</code> is true,
* returns a new session.
* <p>
* If <code>create</code> is <code>false</code> and the request has no valid
* <code>HttpSession</code>, this method returns <code>null</code>.
* <p>
* To make sure the session is properly maintained, you must call this
* method before the response is committed. If the container is using
* cookies to maintain session integrity and is asked to create a new
* session when the response is committed, an IllegalStateException is
* thrown.
*
* @param create
* <code>true</code> to create a new session for this request if
* necessary; <code>false</code> to return <code>null</code> if
* there's no current session
* @return the <code>HttpSession</code> associated with this request or
* <code>null</code> if <code>create</code> is <code>false</code>
* and the request has no valid session
* @see #getSession()
*/
public HttpSession getSession(boolean create);
/**
* Returns the current session associated with this request, or if the
* request does not have a session, creates one.
*
* @return the <code>HttpSession</code> associated with this request
* @see #getSession(boolean)
*/
public HttpSession getSession();