Ja-Jakarta
Translation

javax.servlet.jsp
クラス JspContext

java.lang.Object
  上位を拡張 javax.servlet.jsp.JspContext
直系の既知のサブクラス:
PageContext

public abstract class JspContext
extends java.lang.Object

JspContext serves as the base class for the PageContext class and abstracts all information that is not specific to servlets. This allows for Simple Tag Extensions to be used outside of the context of a request/response Servlet.

The JspContext provides a number of facilities to the page/component author and page implementor, including:

Methods Intended for Container Generated Code

The following methods enable the management of nested JspWriter streams to implement Tag Extensions: pushBody() and popBody()

Methods Intended for JSP authors

Some methods provide uniform access to the diverse objects representing scopes. The implementation must use the underlying machinery corresponding to that scope, so information can be passed back and forth between the underlying environment (e.g. Servlets) and JSP pages. The methods are: setAttribute(), getAttribute(), findAttribute(), removeAttribute(), getAttributesScope() and getAttributeNamesInScope().

The following methods provide convenient access to implicit objects: getOut()

The following methods provide programmatic access to the Expression Language evaluator: getExpressionEvaluator(), getVariableResolver()

導入されたバージョン:
2.0

コンストラクタの概要
JspContext()
          Sole constructor.
 
メソッドの概要
abstract  java.lang.Object findAttribute(java.lang.String name)
          Searches for the named attribute in page, request, session (if valid), and application scope(s) in order and returns the value associated or null.
abstract  java.lang.Object getAttribute(java.lang.String name)
          Returns the object associated with the name in the page scope or null if not found.
abstract  java.lang.Object getAttribute(java.lang.String name, int scope)
          Return the object associated with the name in the specified scope or null if not found.
abstract  java.util.Enumeration getAttributeNamesInScope(int scope)
          Enumerate all the attributes in a given scope.
abstract  int getAttributesScope(java.lang.String name)
          Get the scope where a given attribute is defined.
abstract  ExpressionEvaluator getExpressionEvaluator()
          Provides programmatic access to the ExpressionEvaluator.
abstract  JspWriter getOut()
          The current value of the out object (a JspWriter).
abstract  VariableResolver getVariableResolver()
          Returns an instance of a VariableResolver that provides access to the implicit objects specified in the JSP specification using this JspContext as the context object.
 JspWriter popBody()
          Return the previous JspWriter "out" saved by the matching pushBody(), and update the value of the "out" attribute in the page scope attribute namespace of the JspContext.
 JspWriter pushBody(java.io.Writer writer)
          Return a new JspWriter object that sends output to the provided Writer.
abstract  void removeAttribute(java.lang.String name)
          Remove the object reference associated with the given name from all scopes.
abstract  void removeAttribute(java.lang.String name, int scope)
          Remove the object reference associated with the specified name in the given scope.
abstract  void setAttribute(java.lang.String name, java.lang.Object value)
          Register the name and value specified with page scope semantics.
abstract  void setAttribute(java.lang.String name, java.lang.Object value, int scope)
          Register the name and value specified with appropriate scope semantics.
 
クラス java.lang.Object から継承されたメソッド
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

コンストラクタの詳細

JspContext

public JspContext()
Sole constructor. (For invocation by subclass constructors, typically implicit.)

メソッドの詳細

setAttribute

public abstract void setAttribute(java.lang.String name,
                                  java.lang.Object value)
Register the name and value specified with page scope semantics. If the value passed in is null, this has the same effect as calling removeAttribute( name, PageContext.PAGE_SCOPE ).

パラメータ:
name - the name of the attribute to set
value - the value to associate with the name, or null if the attribute is to be removed from the page scope.
例外:
java.lang.NullPointerException - if the name is null

setAttribute

public abstract void setAttribute(java.lang.String name,
                                  java.lang.Object value,
                                  int scope)
Register the name and value specified with appropriate scope semantics. If the value passed in is null, this has the same effect as calling removeAttribute( name, scope ).

パラメータ:
name - the name of the attribute to set
value - the object to associate with the name, or null if the attribute is to be removed from the specified scope.
scope - the scope with which to associate the name/object
例外:
java.lang.NullPointerException - if the name is null
java.lang.IllegalArgumentException - if the scope is invalid
java.lang.IllegalStateException - if the scope is PageContext.SESSION_SCOPE but the page that was requested does not participate in a session or the session has been invalidated.

getAttribute

public abstract java.lang.Object getAttribute(java.lang.String name)
Returns the object associated with the name in the page scope or null if not found.

パラメータ:
name - the name of the attribute to get
戻り値:
the object associated with the name in the page scope or null if not found.
例外:
java.lang.NullPointerException - if the name is null

getAttribute

public abstract java.lang.Object getAttribute(java.lang.String name,
                                              int scope)
Return the object associated with the name in the specified scope or null if not found.

パラメータ:
name - the name of the attribute to set
scope - the scope with which to associate the name/object
戻り値:
the object associated with the name in the specified scope or null if not found.
例外:
java.lang.NullPointerException - if the name is null
java.lang.IllegalArgumentException - if the scope is invalid
java.lang.IllegalStateException - if the scope is PageContext.SESSION_SCOPE but the page that was requested does not participate in a session or the session has been invalidated.

findAttribute

public abstract java.lang.Object findAttribute(java.lang.String name)
Searches for the named attribute in page, request, session (if valid), and application scope(s) in order and returns the value associated or null.

パラメータ:
name - the name of the attribute to search for
戻り値:
the value associated or null
例外:
java.lang.NullPointerException - if the name is null

removeAttribute

public abstract void removeAttribute(java.lang.String name)
Remove the object reference associated with the given name from all scopes. Does nothing if there is no such object.

パラメータ:
name - The name of the object to remove.
例外:
java.lang.NullPointerException - if the name is null

removeAttribute

public abstract void removeAttribute(java.lang.String name,
                                     int scope)
Remove the object reference associated with the specified name in the given scope. Does nothing if there is no such object.

パラメータ:
name - The name of the object to remove.
scope - The scope where to look.
例外:
java.lang.IllegalArgumentException - if the scope is invalid
java.lang.IllegalStateException - if the scope is PageContext.SESSION_SCOPE but the page that was requested does not participate in a session or the session has been invalidated.
java.lang.NullPointerException - if the name is null

getAttributesScope

public abstract int getAttributesScope(java.lang.String name)
Get the scope where a given attribute is defined.

パラメータ:
name - the name of the attribute to return the scope for
戻り値:
the scope of the object associated with the name specified or 0
例外:
java.lang.NullPointerException - if the name is null

getAttributeNamesInScope

public abstract java.util.Enumeration getAttributeNamesInScope(int scope)
Enumerate all the attributes in a given scope.

パラメータ:
scope - the scope to enumerate all the attributes for
戻り値:
an enumeration of names (java.lang.String) of all the attributes the specified scope
例外:
java.lang.IllegalArgumentException - if the scope is invalid
java.lang.IllegalStateException - if the scope is PageContext.SESSION_SCOPE but the page that was requested does not participate in a session or the session has been invalidated.

getOut

public abstract JspWriter getOut()
The current value of the out object (a JspWriter).

戻り値:
the current JspWriter stream being used for client response

getExpressionEvaluator

public abstract ExpressionEvaluator getExpressionEvaluator()
Provides programmatic access to the ExpressionEvaluator. The JSP Container must return a valid instance of an ExpressionEvaluator that can parse EL expressions.

戻り値:
A valid instance of an ExpressionEvaluator.
導入されたバージョン:
2.0

getVariableResolver

public abstract VariableResolver getVariableResolver()
Returns an instance of a VariableResolver that provides access to the implicit objects specified in the JSP specification using this JspContext as the context object.

戻り値:
A valid instance of a VariableResolver.
導入されたバージョン:
2.0

pushBody

public JspWriter pushBody(java.io.Writer writer)
Return a new JspWriter object that sends output to the provided Writer. Saves the current "out" JspWriter, and updates the value of the "out" attribute in the page scope attribute namespace of the JspContext.

The returned JspWriter must implement all methods and behave as though it were unbuffered. More specifically:

パラメータ:
writer - The Writer for the returned JspWriter to send output to.
戻り値:
a new JspWriter that writes to the given Writer.
導入されたバージョン:
2.0

popBody

public JspWriter popBody()
Return the previous JspWriter "out" saved by the matching pushBody(), and update the value of the "out" attribute in the page scope attribute namespace of the JspContext.

戻り値:
the saved JspWriter.

Ja-Jakarta
Translation

Copyright © 2000- The Apache Software Foundation. All rights Reserved.