redirecttag.java

structs源码

/*
 * $Id: RedirectTag.java 471754 2006-11-06 14:55:09Z husted $
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.struts.taglib.logic;

import org.apache.struts.taglib.TagUtils;
import org.apache.struts.util.MessageResources;

import javax.servlet.http.HttpServletResponse;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.tagext.TagSupport;

import java.io.IOException;

import java.net.MalformedURLException;

import java.util.Map;

/**
 * Generate a URL-encoded redirect to the specified URI.
 *
 * @version $Rev: 471754 $ $Date: 2004-10-16 12:38:42 -0400 (Sat, 16 Oct 2004)
 *          $
 */
public class RedirectTag extends TagSupport {
    /**
     * The message resources for this package.
     */
    protected static MessageResources messages =
        MessageResources.getMessageResources(
            "org.apache.struts.taglib.logic.LocalStrings");

    // ------------------------------------------------------------- Properties

    /**
     * The anchor to be added to the end of the generated hyperlink.
     */
    protected String anchor = null;

    /**
     * The logical forward name from which to retrieve the redirect URI.
     */
    protected String forward = null;

    /**
     * The redirect URI.
     */
    protected String href = null;

    /**
     * The JSP bean name for query parameters.
     */
    protected String name = null;

    /**
     * The module-relative page URL (beginning with a slash) to which this
     * redirect will be rendered.
     */
    protected String page = null;

    /**
     * The module-relative action (beginning with a slash) which will be
     * called by this link
     */
    protected String action = null;

    /**
     * The module prefix (beginning with a slash) which will be used to find
     * the action for this link.
     */
    protected String module = null;

    /**
     * The single-parameter request parameter name to generate.
     */
    protected String paramId = null;

    /**
     * The single-parameter JSP bean name.
     */
    protected String paramName = null;

    /**
     * The single-parameter JSP bean property.
     */
    protected String paramProperty = null;

    /**
     * The single-parameter JSP bean scope.
     */
    protected String paramScope = null;

    /**
     * The JSP bean property name for query parameters.
     */
    protected String property = null;

    /**
     * The scope of the bean specified by the name property, if any.
     */
    protected String scope = null;

    /**
     * Include our transaction control token?
     */
    protected boolean transaction = false;

    /**
     * Use character encoding from ServletResponse#getCharacterEncoding to get
     * bytes of the url string for urlencoding?
     */
    protected boolean useLocalEncoding = false;

    public String getAnchor() {
        return (this.anchor);
    }

    public void setAnchor(String anchor) {
        this.anchor = anchor;
    }

    public String getForward() {
        return (this.forward);
    }

    public void setForward(String forward) {
        this.forward = forward;
    }

    public String getHref() {
        return (this.href);
    }

    public void setHref(String href) {
        this.href = href;
    }

    public String getName() {
        return (this.name);
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getPage() {
        return (this.page);
    }

    public void setPage(String page) {
        this.page = page;
    }

    public String getAction() {
        return (this.action);
    }

    public void setAction(String action) {
        this.action = action;
    }

    public String getModule() {
        return (this.module);
    }

    public void setModule(String module) {
        this.module = module;
    }

    public String getParamId() {
        return (this.paramId);
    }

    public void setParamId(String paramId) {
        this.paramId = paramId;
    }

    public String getParamName() {
        return (this.paramName);
    }

    public void setParamName(String paramName) {
        this.paramName = paramName;
    }

    public String getParamProperty() {
        return (this.paramProperty);
    }

    public void setParamProperty(String paramProperty) {
        this.paramProperty = paramProperty;
    }

    public String getParamScope() {
        return (this.paramScope);
    }

    public void setParamScope(String paramScope) {
        this.paramScope = paramScope;
    }

    public String getProperty() {
        return (this.property);
    }

    public void setProperty(String property) {
        this.property = property;
    }

    public String getScope() {
        return (this.scope);
    }

    public void setScope(String scope) {
        this.scope = scope;
    }

    public boolean getTransaction() {
        return (this.transaction);
    }

    public void setTransaction(boolean transaction) {
        this.transaction = transaction;
    }

    public boolean isUseLocalEncoding() {
        return useLocalEncoding;
    }

    public void setUseLocalEncoding(boolean b) {
        useLocalEncoding = b;
    }

    // --------------------------------------------------------- Public Methods

    /**
     * Defer generation until the end of this tag is encountered.
     *
     * @throws JspException if a JSP exception has occurred
     */
    public int doStartTag() throws JspException {
        return (SKIP_BODY);
    }

    /**
     * Render the redirect and skip the remainder of this page.
     *
     * @throws JspException if a JSP exception has occurred
     */
    public int doEndTag() throws JspException {
        this.doRedirect(this.generateRedirectURL());

        return (SKIP_PAGE);
    }

    /**
     * Calculate the url to redirect to.
     *
     * @throws JspException
     * @since Struts 1.2
     */
    protected String generateRedirectURL()
        throws JspException {
        Map params =
            TagUtils.getInstance().computeParameters(pageContext, paramId,
                paramName, paramProperty, paramScope, name, property, scope,
                transaction);

        String url = null;

        try {
            url = TagUtils.getInstance().computeURLWithCharEncoding(pageContext,
                    forward, href, page, action, module, params, anchor, true,
                    useLocalEncoding);
        } catch (MalformedURLException e) {
            TagUtils.getInstance().saveException(pageContext, e);
            throw new JspException(messages.getMessage("redirect.url",
                    e.toString()));
        }

        return url;
    }

    /**
     * Redirect to the given url converting exceptions to JspException.
     *
     * @param url The path to redirect to.
     * @throws JspException
     * @since Struts 1.2
     */
    protected void doRedirect(String url)
        throws JspException {
        HttpServletResponse response =
            (HttpServletResponse) pageContext.getResponse();

        try {
            response.sendRedirect(url);
        } catch (IOException e) {
            TagUtils.getInstance().saveException(pageContext, e);
            throw new JspException(e.getMessage());
        }
    }

    /**
     * Release any acquired resources.
     */
    public void release() {
        super.release();
        anchor = null;
        forward = null;
        href = null;
        name = null;
        page = null;
        action = null;
        paramId = null;
        paramName = null;
        paramProperty = null;
        paramScope = null;
        property = null;
        scope = null;
    }
}