confighelper.java

这是一个轻便的j2ee的web应用框架,是一个在多个项目中运用的实际框架,采用struts,hebinate,xml等技术,有丰富的tag,role,navigation,session,dictio

/*
 * $Header: /sfroot/cvs/esimple/src/core/org/apache/struts/config/ConfigHelper.java,v 1.1.1.1 2004/09/08 06:38:32 lava Exp $
 * $Revision: 1.1.1.1 $
 * $Date: 2004/09/08 06:38:32 $
 *
 * ====================================================================
 *
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 1999-2001 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "The Jakarta Project", "Struts", and "Apache Software
 *    Foundation" must not be used to endorse or promote products derived
 *    from this software without prior written permission. For written
 *    permission, please contact [e-mail].
 *
 * 5. Products derived from this software may not be called "Apache"
 *    nor may "Apache" appear in their names without prior written
 *    permission of the Apache Group.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */

package org.apache.struts.config;

import java.util.Iterator;
import java.util.Locale;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import javax.sql.DataSource;

import org.apache.struts.Globals;
import org.apache.struts.action.ActionError;
import org.apache.struts.action.ActionErrors;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionFormBean;
import org.apache.struts.action.ActionFormBeans;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionForwards;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.action.ActionMappings;
import org.apache.struts.action.ActionMessages;
import org.apache.struts.upload.MultipartRequestWrapper;
import org.apache.struts.util.MessageResources;

/**
 * NOTE: THIS CLASS IS UNDER ACTIVE DEVELOPMENT.
 * THE CURRENT CODE IS WRITTEN FOR CLARITY NOT EFFICIENCY.
 * NOT EVERY API FUNCTION HAS BEEN IMPLEMENTED YET.
 *
 * A helper object to expose the Struts shared resources,
 * which are be stored in the application, session, or
 * request contexts, as appropriate.
 *
 * An instance should be created for each request
 * processed. The  methods which return resources from
 * the request or session contexts are not thread-safe.
 *
 * Provided for use by other servlets in the application
 * so they can easily access the Struts shared resources.
 *
 * The resources are stored under attributes in the
 * application, session, or request contexts.
 *
 * The ActionConfig methods simply return the resources
 * from under the context and key used by the Struts
 * ActionServlet when the resources are created.
 *
 * @since 1.1
 * @author Ted Husted
 * @author Luis Arias <[e-mail]>
 * @version $Revision: 1.1.1.1 $ $Date: 2004/09/08 06:38:32 $
 */
public class ConfigHelper implements ConfigHelperInterface {

    // --------------------------------------------------------  Properites

    /**
     * The application associated with this instance.
     */
    private ServletContext application = null;

    /**
     * Set the application associated with this instance.
     * [servlet.getServletContext()]
     */
    public void setApplication(ServletContext application) {
        this.application = application;
    }

    /**
     * The session associated with this instance.
     */
    private HttpSession session = null;

    /**
     * Set the session associated with this instance.
     */
    public void setSession(HttpSession session) {
        this.session = session;
    }

    /**
     * The request associated with this instance.
     */
    private HttpServletRequest request = null;

    /**
     * Set the request associated with this object.
     * Session object is also set or cleared.
     */
    public void setRequest(HttpServletRequest request) {
        this.request = request;
        if (this.request == null)
            setSession(null);
        else
            setSession(this.request.getSession());
    }

    /**
     * The response associated with this instance.
     */
    private HttpServletResponse response = null;

    /**
     * Set the response associated with this isntance.
     * Session object is also set or cleared.
     */
    public void setResponse(HttpServletResponse response) {
        this.response = response;
    }

    /**
     * The forward associated with this instance.
     */
    private ActionForward forward = null;

    /**
     * Set the forward associated with this instance.
     */
    public void setForward(ActionForward forward) {
        this.forward = forward;
    }

    /**
     * Set the application and request for this object instance.
     * The ServletContext can be set by any servlet in the application.
     * The request should be the instant request.
     * Most of the other methods retrieve their own objects
     * by reference to the application, request, or session
     * attributes.
     * Do not call other methods without setting these first!
     * This is also called by the convenience constructor.
     *
     * @param application - The associated ServletContext.
     * @param request - The associated HTTP request.
     * @param response - The associated HTTP response.
     */
    public void setResources(
        ServletContext application,
        HttpServletRequest request,
        HttpServletResponse response) {
        setApplication(application);
        setRequest(request);
        setResponse(response);
    }

    // ------------------------------------------------ Application Context

    /**
     * The strong>default</strong>
     * configured data source (which must implement
     * <code>javax.sql.DataSource</code>),
     * if one is configured for this application.
     */
    public DataSource getDataSource() {

        if (this.application == null)
            return null;
        return (DataSource) this.application.getAttribute(Globals.DATA_SOURCE_KEY);

    }

    public ActionMessages getActionMessages() {

        if (this.application == null)
            return null;
        return (ActionMessages) this.application.getAttribute(Globals.MESSAGE_KEY);

    }

    /**
     * The <code>org.apache.struts.action.ActionFormBeans</code> collection
     * for this application.
     */
    public ActionFormBeans getActionFormBeans() {

        if (this.application == null) {
            return null;
        }
        return (ActionFormBeans) this.application.getAttribute(Globals.FORM_BEANS_KEY);

    }

    /**
     * The <code>org.apache.struts.action.ActionForwards</code> collection
     * for this application.
     */
    public ActionForwards getActionForwards() {

        if (this.application == null) {
            return null;
        }
        return (ActionForwards) this.application.getAttribute(Globals.FORWARDS_KEY);

    }

    /**
     * The context attributes key under which our
     * <code>org.apache.struts.action.ActionMappings</code> collection
     * is normally stored, unless overridden when initializing our
     * ActionServlet.
     */
    public ActionMappings getActionMappings() {
        if (this.application == null) {
            return null;
        }
        return (ActionMappings) this.application.getAttribute(Globals.MAPPINGS_KEY);
    }

    /**
     * The application resources for this application.
     */
    public MessageResources getMessageResources() {

        if (this.application == null) {
            return null;
        }
        return (MessageResources) this.application.getAttribute(Globals.MESSAGES_KEY);

    }

    /**
     * The path-mapped pattern (<code>/action/*</code>) or
     * extension mapped pattern ((<code>*.do</code>)
     * used to determine our Action URIs in this application.
     */
    public String getServletMapping() {

        if (this.application == null) {
            return null;
        }
        return (String) this.application.getAttribute(Globals.SERVLET_KEY);

    }

    // ---------------------------------------------------- Session Context

    /**
     * The <code>java.util.Locale</code> for the user, if any.
     * If a default locale object is not in the user's session,
     * the system default locale is returned.
     * If used, the user locale is typically set during login
     * processing under the key <code>Globals.LOCALE_KEY</code>.
     */
    public Locale getLocale() {
        Locale locale = null;

        if (session != null) {
            locale = (Locale) session.getAttribute(Globals.LOCALE_KEY);
        }

        if ((locale == null) && (request != null)) {
            locale = request.getLocale();
        }

        return locale;
    }

    /**
     * The transaction token stored in this session, if it is used.
     */
    public String getToken() {

        if (this.session == null) {
            return null;
        }
        return (String) session.getAttribute(Globals.TRANSACTION_TOKEN_KEY);

    }

    // ---------------------------------------------------- Request Context

    /**
     * The <code>org.apache.struts.action.ActionErrors</code> object,
     * for this request.
     */
    public ActionErrors getActionErrors() {

        if (this.request == null) {
            return null;
        }
        return (ActionErrors) this.request.getAttribute(Globals.ERROR_KEY);

    }

    /**
     * The runtime JspException that may be been thrown by a Struts tag
     * extension, or compatible presentation extension, and placed
     * in the request.
     */
    public Throwable getException() {

        if (this.request == null) {
            return null;
        }
        return (Throwable) this.request.getAttribute(Globals.EXCEPTION_KEY);

    }

    /**
     * The multipart object for this request.
     */
    public MultipartRequestWrapper getMultipartRequestWrapper() {

        if (this.request == null) {
            return null;
        }
        return (MultipartRequestWrapper) this.request.getAttribute(Globals.MULTIPART_KEY);
    }

    /**
      * The <code>org.apache.struts.ActionMapping</code>
      * instance for this request.
      */
    public ActionMapping getMapping() {

        if (this.request == null) {
            return null;
        }
        return (ActionMapping) this.request.getAttribute(Globals.MAPPING_KEY);

    }

    // ---------------------------------------------------- Utility Methods

    /**
     * Return true if a message string for the specified message key
     * is present for the user's Locale.
     *
     * @param key Message key
     */
    public boolean isMessage(String key) {

        // Look up the requested MessageResources
        MessageResources resources = getMessageResources();

        if (resources == null) {
            return false;
        }

        // Return the requested message presence indicator
        return (resources.isPresent(getLocale(), key));

    }

    /*
     * Retrieve and return the <code>ActionForm</code> bean associated with
     * this mapping, creating and stashing one if necessary.  If there is no
     * form bean associated with this mapping, return <code>null</code>.
     *
     */
    public ActionForm getActionForm() {

        // Is there a mapping associated with this request?
        ActionMapping mapping = getMapping();
        if (mapping == null)
            return (null);

        // Is there a form bean associated with this mapping?
        String attribute = mapping.getAttribute();
        if (attribute == null)
            return (null);

        // Look up the existing form bean, if any
        ActionForm instance = null;
        if ("request".equals(mapping.getScope())) {
            instance = (ActionForm) this.request.getAttribute(attribute);
        } else {
            instance = (ActionForm) this.session.getAttribute(attribute);
        }

        return instance;
    }

    /**
     * Return the form bean definition associated with the specified
     * logical name, if any; otherwise return <code>null</code>.
     *
     * @param name Logical name of the requested form bean definition
     */
    public ActionFormBean getFormBean(String name) {

        ActionFormBeans formBeans = getActionFormBeans();

        if (formBeans == null)
            return null;
        return formBeans.findFormBean(name);

    }

    /**
     * Return the forwarding associated with the specified logical name,
     * if any; otherwise return <code>null</code>.
     *
     * @param name Logical name of the requested forwarding
     */
    public ActionForward getActionForward(String name) {

        ActionForwards forwards = getActionForwards();

        if (forwards == null)
            return null;
        return forwards.findForward(name);

    }

    /**
     * Return the mapping associated with the specified request path, if any;