Java PageContext.REQUEST_SCOPE属性代码示例

/**
 * Determines the scope for a given input {@code String}.
 * <p>If the {@code String} does not match 'request', 'session',
 * 'page' or 'application', the method will return {@link PageContext#PAGE_SCOPE}.
 * @param scope the {@code String} to inspect
 * @return the scope found, or {@link PageContext#PAGE_SCOPE} if no scope matched
 * @throws IllegalArgumentException if the supplied {@code scope} is {@code null}
 */
public static int getScope(String scope) {
	Assert.notNull(scope, "Scope to search for cannot be null");
	if (scope.equals(SCOPE_REQUEST)) {
		return PageContext.REQUEST_SCOPE;
	}
	else if (scope.equals(SCOPE_SESSION)) {
		return PageContext.SESSION_SCOPE;
	}
	else if (scope.equals(SCOPE_APPLICATION)) {
		return PageContext.APPLICATION_SCOPE;
	}
	else {
		return PageContext.PAGE_SCOPE;
	}
}
 

/**
 * Locate or create the bean associated with our form.
 * @throws JspException
 * @since Struts 1.1
 */
protected void initFormBean() throws JspException {
    int scope = PageContext.SESSION_SCOPE;
    if ("request".equalsIgnoreCase(beanScope)) {
        scope = PageContext.REQUEST_SCOPE;
    }
    
    Object bean = pageContext.getAttribute(beanName, scope);
    if (bean == null) {
        // New and improved - use the values from the action mapping
        bean =
            RequestUtils.createActionForm(
                (HttpServletRequest) pageContext.getRequest(),
                mapping,
                moduleConfig,
                servlet);
        if (bean instanceof ActionForm) {
            ((ActionForm) bean).reset(mapping, (HttpServletRequest) pageContext.getRequest());
        }
        if (bean == null) {
            throw new JspException(messages.getMessage("formTag.create", beanType));
        }
        pageContext.setAttribute(beanName, bean, scope);
    }
    pageContext.setAttribute(Constants.BEAN_KEY, bean, PageContext.REQUEST_SCOPE);
}
 

/**
 * Converts the given string description of a scope to the corresponding
 * PageContext constant.
 *
 * The validity of the given scope has already been checked by the
 * appropriate TLV.
 *
 * @param scope String description of scope
 *
 * @return PageContext constant corresponding to given scope description
 * 
 * taken from org.apache.taglibs.standard.tag.common.core.Util  
 */
public static int getScope(String scope){
    int ret = PageContext.PAGE_SCOPE;
    
    if("request".equalsIgnoreCase(scope)){
        ret = PageContext.REQUEST_SCOPE;
    }else if("session".equalsIgnoreCase(scope)){
        ret = PageContext.SESSION_SCOPE;
    }else if("application".equalsIgnoreCase(scope)){
        ret = PageContext.APPLICATION_SCOPE;
    }
    
    return ret;
}
 

/** This writes the initial html.
 * @throws JspException if any error occurs.
 * @return EVAL_BODY_TAG if the JSP engine should evaluate the tag body, otherwise return SKIP_BODY.
 */
public int doStartTag() throws JspException {
    // Valid combinations are ( action | action,url | useBean,url )
    if( ( action==null&&(m_url==null||m_useBean==null) ) ||
        ( action!=null&&(m_useBean!=null) ))
        throw new JspException("Invalid parameters, either provide 'action' or 'useBean'/'url'");

    CustomTag.pushParent(this, pageContext);

    // Set the bean name we should be using
    if(m_useBean!=null) {
        beanName=m_useBean;
        // Find the scope of the bean, error out if it does not exist
        int scope = pageContext.getAttributesScope(m_useBean);
        switch(scope) {
            case PageContext.SESSION_SCOPE:
                beanScope="session";
                break;
            case PageContext.REQUEST_SCOPE:
                beanScope="request";
                break;
            default:
                throw new JspException("Can't find object of name'"+m_useBean+"' in session or request scope?");
        }
    }

    int i = super.doStartTag();
    doStartTagExt();
    return i;
}
 

/**
 * Converts the given string description of a scope to the corresponding
 * PageContext constant.
 *
 * The validity of the given scope has already been checked by the
 * appropriate TLV.
 *
 * @param scope
 *            String description of scope
 *
 * @return PageContext constant corresponding to given scope description
 * 
 *         taken from org.apache.taglibs.standard.tag.common.core.Util
 */
public static int getScope(String scope) {
	int ret = PageContext.PAGE_SCOPE;

	if ("request".equalsIgnoreCase(scope)) {
		ret = PageContext.REQUEST_SCOPE;
	} else if ("session".equalsIgnoreCase(scope)) {
		ret = PageContext.SESSION_SCOPE;
	} else if ("application".equalsIgnoreCase(scope)) {
		ret = PageContext.APPLICATION_SCOPE;
	}

	return ret;
}