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JspContextWrapper.javaAPI DocGlassfish v2 API13740Fri May 04 22:32:54 BST 2007org.apache.jasper.runtime

JspContextWrapper

public class JspContextWrapper extends javax.servlet.jsp.PageContext
Implementation of a JSP Context Wrapper. The JSP Context Wrapper is a JspContext created and maintained by a tag handler implementation. It wraps the Invoking JSP Context, that is, the JspContext instance passed to the tag handler by the invoking page via setJspContext().
author
Kin-man Chung
author
Jan Luehe

Fields Summary
private javax.servlet.jsp.PageContext
invokingJspCtxt
private Hashtable
pageAttributes
private ArrayList
nestedVars
private ArrayList
atBeginVars
private ArrayList
atEndVars
private Map
aliases
private Hashtable
originalNestedVars
private ELContext
elContext
Constructors Summary
public JspContextWrapper(javax.servlet.jsp.JspContext jspContext, ArrayList nestedVars, ArrayList atBeginVars, ArrayList atEndVars, Map aliases)

        this.invokingJspCtxt = (PageContext) jspContext;
	this.nestedVars = nestedVars;
	this.atBeginVars = atBeginVars;
	this.atEndVars = atEndVars;
	this.pageAttributes = new Hashtable(16);
	this.aliases = aliases;

	if (nestedVars != null) {
	    this.originalNestedVars = new Hashtable(nestedVars.size());
	}
	syncBeginTagFile();
Methods Summary
private voidcopyTagToPageScope(int scope)
Copies the variables of the given scope from the virtual page scope of this JSP context wrapper to the page scope of the invoking JSP context.

param
scope variable scope (one of NESTED, AT_BEGIN, or AT_END)

	Iterator iter = null;

	switch (scope) {
	case VariableInfo.NESTED:
	    if (nestedVars != null) {
		iter = nestedVars.iterator();
	    }
	    break;
	case VariableInfo.AT_BEGIN:
	    if (atBeginVars != null) {
		iter = atBeginVars.iterator();
	    }
	    break;
	case VariableInfo.AT_END:
	    if (atEndVars != null) {
		iter = atEndVars.iterator();
	    }
	    break;
	}

	while ((iter != null) && iter.hasNext()) {
	    String varName = (String) iter.next();
	    Object obj = getAttribute(varName);
	    varName = findAlias(varName);
	    if (obj != null) {
		invokingJspCtxt.setAttribute(varName, obj);
	    } else {
		invokingJspCtxt.removeAttribute(varName, PAGE_SCOPE);
	    }
	}
private java.lang.StringfindAlias(java.lang.String varName)
Checks to see if the given variable name is used as an alias, and if so, returns the variable name for which it is used as an alias.

param
varName The variable name to check
return
The variable name for which varName is used as an alias, or varName if it is not being used as an alias


	if (aliases == null)
	    return varName;

	String alias = (String) aliases.get(varName);
	if (alias == null) {
	    return varName;
	}
	return alias;
public java.lang.ObjectfindAttribute(java.lang.String name)


	if (name == null) {
	    throw new NullPointerException(
	            Localizer.getMessage("jsp.error.attribute.null_name"));
	}

        Object o = pageAttributes.get(name);
        if (o == null) {
	    o = invokingJspCtxt.getAttribute(name, REQUEST_SCOPE);
	    if (o == null) {
		if (getSession() != null) {
		    o = invokingJspCtxt.getAttribute(name, SESSION_SCOPE);
		}
		if (o == null) {
		    o = invokingJspCtxt.getAttribute(name, APPLICATION_SCOPE);
		} 
	    }
	}

	return o;
public voidforward(java.lang.String relativeUrlPath)

	invokingJspCtxt.forward(relativeUrlPath);
public java.lang.ObjectgetAttribute(java.lang.String name)


	if (name == null) {
	    throw new NullPointerException(
	            Localizer.getMessage("jsp.error.attribute.null_name"));
	}

	return pageAttributes.get(name);
public java.lang.ObjectgetAttribute(java.lang.String name, int scope)


	if (name == null) {
	    throw new NullPointerException(
	            Localizer.getMessage("jsp.error.attribute.null_name"));
	}

	if (scope == PAGE_SCOPE) {
	    return pageAttributes.get(name);
	}

	return invokingJspCtxt.getAttribute(name, scope);
public java.util.EnumerationgetAttributeNamesInScope(int scope)

        if (scope == PAGE_SCOPE) {
            return pageAttributes.keys();
	}

	return invokingJspCtxt.getAttributeNamesInScope(scope);
public intgetAttributesScope(java.lang.String name)


	if (name == null) {
	    throw new NullPointerException(
	            Localizer.getMessage("jsp.error.attribute.null_name"));
	}

	if (pageAttributes.get(name) != null) {
	    return PAGE_SCOPE;
	} else {
	    return invokingJspCtxt.getAttributesScope(name);
	}
public javax.el.ELContextgetELContext()

        if (elContext == null) {
            PageContext pc = invokingJspCtxt;
            while (pc instanceof JspContextWrapper) {
                pc = ((JspContextWrapper)pc).invokingJspCtxt;
            }
            PageContextImpl pci = (PageContextImpl) pc;
            elContext = pci.getJspApplicationContext().createELContext(
                              invokingJspCtxt.getELContext().getELResolver());
            elContext.putContext(javax.servlet.jsp.JspContext.class, this);
            ((ELContextImpl)elContext).setVariableMapper(
                new VariableMapperImpl());
        }
        return elContext;
public java.lang.ExceptiongetException()

	return invokingJspCtxt.getException();
public javax.servlet.jsp.el.ExpressionEvaluatorgetExpressionEvaluator()

	return invokingJspCtxt.getExpressionEvaluator();
public javax.servlet.jsp.JspWritergetOut()

	return invokingJspCtxt.getOut();
public java.lang.ObjectgetPage()

	return invokingJspCtxt.getPage();
public javax.servlet.ServletRequestgetRequest()

	return invokingJspCtxt.getRequest();
public javax.servlet.ServletResponsegetResponse()

	return invokingJspCtxt.getResponse();
public static javax.servlet.jsp.PageContextgetRootPageContext(javax.servlet.jsp.PageContext pc)

        while (pc instanceof JspContextWrapper) {
            pc = ((JspContextWrapper)pc).invokingJspCtxt;
        }
        return pc;
public javax.servlet.ServletConfiggetServletConfig()

	return invokingJspCtxt.getServletConfig();
public javax.servlet.ServletContextgetServletContext()

	return invokingJspCtxt.getServletContext();
public javax.servlet.http.HttpSessiongetSession()

	return invokingJspCtxt.getSession();
public javax.servlet.jsp.el.VariableResolvergetVariableResolver()

	return null;
public voidhandlePageException(java.lang.Exception ex)

	// Should never be called since handleException() called with a
	// Throwable in the generated servlet.
	handlePageException((Throwable) ex);
public voidhandlePageException(java.lang.Throwable t)

	invokingJspCtxt.handlePageException(t);
public voidinclude(java.lang.String relativeUrlPath)

	invokingJspCtxt.include(relativeUrlPath);
public voidinclude(java.lang.String relativeUrlPath, boolean flush)

	invokingJspCtxt.include(relativeUrlPath, flush);
public voidinitialize(javax.servlet.Servlet servlet, javax.servlet.ServletRequest request, javax.servlet.ServletResponse response, java.lang.String errorPageURL, boolean needsSession, int bufferSize, boolean autoFlush)
public javax.servlet.jsp.JspWriterpopBody()

        return invokingJspCtxt.popBody();
public javax.servlet.jsp.tagext.BodyContentpushBody()

	return invokingJspCtxt.pushBody();
public javax.servlet.jsp.JspWriterpushBody(java.io.Writer writer)

	return invokingJspCtxt.pushBody(writer);
public voidrelease()

	invokingJspCtxt.release();
public voidremoveAttribute(java.lang.String name)


	if (name == null) {
	    throw new NullPointerException(
	            Localizer.getMessage("jsp.error.attribute.null_name"));
	}

	pageAttributes.remove(name);
	invokingJspCtxt.removeAttribute(name, REQUEST_SCOPE);
	if (getSession() != null) {
	    invokingJspCtxt.removeAttribute(name, SESSION_SCOPE);
	}
	invokingJspCtxt.removeAttribute(name, APPLICATION_SCOPE);
public voidremoveAttribute(java.lang.String name, int scope)


	if (name == null) {
	    throw new NullPointerException(
	            Localizer.getMessage("jsp.error.attribute.null_name"));
	}

	if (scope == PAGE_SCOPE){
	    pageAttributes.remove(name);
	} else {
	    invokingJspCtxt.removeAttribute(name, scope);
	}
private voidrestoreNestedVariables()
Restores the values of any NESTED variables in the invoking JSP context.

	if (nestedVars != null) {
	    Iterator iter = nestedVars.iterator();
	    while (iter.hasNext()) {
		String varName = (String) iter.next();
		varName = findAlias(varName);
		Object obj = originalNestedVars.get(varName);
		if (obj != null) {
		    invokingJspCtxt.setAttribute(varName, obj);
		} else {
		    invokingJspCtxt.removeAttribute(varName, PAGE_SCOPE);
		}
	    }
	}
private voidsaveNestedVariables()
Saves the values of any NESTED variables that are present in the invoking JSP context, so they can later be restored.

	if (nestedVars != null) {
	    Iterator iter = nestedVars.iterator();
	    while (iter.hasNext()) {
		String varName = (String) iter.next();
		varName = findAlias(varName);
		Object obj = invokingJspCtxt.getAttribute(varName);
		if (obj != null) {
		    originalNestedVars.put(varName, obj);
		}
	    }
	}
public voidsetAttribute(java.lang.String name, java.lang.Object value)


	if (name == null) {
	    throw new NullPointerException(
	            Localizer.getMessage("jsp.error.attribute.null_name"));
	}

	if (value != null) {
	    pageAttributes.put(name, value);
	} else {
	    removeAttribute(name, PAGE_SCOPE);
	}
public voidsetAttribute(java.lang.String name, java.lang.Object value, int scope)


	if (name == null) {
	    throw new NullPointerException(
	            Localizer.getMessage("jsp.error.attribute.null_name"));
	}

	if (scope == PAGE_SCOPE) {
	    if (value != null) {
		pageAttributes.put(name, value);
	    } else {
		removeAttribute(name, PAGE_SCOPE);
	    }
	} else {
	    invokingJspCtxt.setAttribute(name, value, scope);
	}
public voidsyncBeforeInvoke()
Synchronize variables before fragment invokation

	copyTagToPageScope(VariableInfo.NESTED);
	copyTagToPageScope(VariableInfo.AT_BEGIN);
public voidsyncBeginTagFile()
Synchronize variables at begin of tag file

	saveNestedVariables();
public voidsyncEndTagFile()
Synchronize variables at end of tag file

	copyTagToPageScope(VariableInfo.AT_BEGIN);
	copyTagToPageScope(VariableInfo.AT_END);
	restoreNestedVariables();