includetag.java

jakarta-struts-1.2.4-src

/*
 * $Header: /home/cvs/jakarta-struts/src/share/org/apache/struts/taglib/bean/IncludeTag.java,v 1.30 2004/03/14 06:23:45 sraeburn Exp $
 * $Revision: 1.30 $
 * $Date: 2004/03/14 06:23:45 $
 *
 * Copyright 1999-2004 The Apache Software Foundation.
 * 
 * Licensed 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.bean;

import java.io.BufferedInputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import java.util.Map;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.tagext.TagSupport;
import org.apache.struts.util.MessageResources;
import org.apache.struts.util.RequestUtils;
import org.apache.struts.taglib.TagUtils;

/**
 * Define the contents of a specified intra-application request as a
 * page scope attribute of type <code>java.lang.String</code>.  If the
 * current request is part of a session, the session identifier will be
 * included in the generated request, so it will be part of the same
 * session.
 * <p>
 * <strong>FIXME</strong>:  In a servlet 2.3 environment, we can use a
 * wrapped response passed to RequestDispatcher.include().
 *
 * @version $Revision: 1.30 $ $Date: 2004/03/14 06:23:45 $
 */

public class IncludeTag extends TagSupport {

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

    /**
     * Buffer size to use when reading the input stream.
     */
    protected static final int BUFFER_SIZE = 256;

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

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

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

    /**
     * The name of the global <code>ActionForward</code> that contains a
     * path to our requested resource.
     */
    protected String forward = null;

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

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

    /**
     * The absolute URL to the resource to be included.
     */
    protected String href = null;

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

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

    /**
     * The name of the scripting variable that will be exposed as a page
     * scope attribute.
     */
    protected String id = null;

    public String getId() {
        return (this.id);
    }

    public void setId(String id) {
        this.id = id;
    }

    /**
     * The message resources for this package.
     */
    protected static MessageResources messages =
        MessageResources.getMessageResources("org.apache.struts.taglib.bean.LocalStrings");

    /**
     * Deprecated method to set the "name" attribute, which has been
     * replaced by the "page" attribute.
     *
     * @deprecated use setPage(String) instead
     */
    public void setName(String name) {
        this.page = name;
    }

    /**
     * The context-relative URI of the page or servlet to be included.
     */
    protected String page = null;

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

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

    /**
     * Include transaction token (if any) in the hyperlink?
     */
    protected boolean transaction = false;

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

    public void setTransaction(boolean transaction) {
        this.transaction = transaction;
    }
    
    protected boolean useLocalEncoding = false;
    
	public boolean isUseLocalEncoding() {
		return useLocalEncoding;
	}

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

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

    /**
     * Define the contents returned for the specified resource as a
     * page scope attribute.
     *
     * @exception JspException if a JSP error occurs
     */
    public int doStartTag() throws JspException {

        // Set up a URLConnection to read the requested resource
        Map params =
            TagUtils.getInstance().computeParameters(
                pageContext,
                null,
                null,
                null,
                null,
                null,
                null,
                null,
                transaction);
        // FIXME - <html:link> attributes
        String urlString = null;
        URL url = null;
        try {
            urlString =
                TagUtils.getInstance().computeURLWithCharEncoding(pageContext, forward, href, page, null,null, params, anchor, false, useLocalEncoding);
            if (urlString.indexOf(':') < 0) {
                HttpServletRequest request = (HttpServletRequest) pageContext.getRequest();
                url = new URL(RequestUtils.requestURL(request), urlString);
            } else {
                url = new URL(urlString);
            }
        } catch (MalformedURLException e) {
            TagUtils.getInstance().saveException(pageContext, e);
            throw new JspException(messages.getMessage("include.url", e.toString()));
        }

        URLConnection conn = null;
        try {
            // Set up the basic connection
            conn = url.openConnection();
            conn.setAllowUserInteraction(false);
            conn.setDoInput(true);
            conn.setDoOutput(false);
            // Add a session id cookie if appropriate
            HttpServletRequest request = (HttpServletRequest) pageContext.getRequest();
            addCookie(conn, urlString, request);
            // Connect to the requested resource
            conn.connect();
        } catch (Exception e) {
            TagUtils.getInstance().saveException(pageContext, e);
            throw new JspException(
                messages.getMessage("include.open", url.toString(), e.toString()));
        }

        // Copy the contents of this URL
        StringBuffer sb = new StringBuffer();
        try {
            BufferedInputStream is = new BufferedInputStream(conn.getInputStream());
            InputStreamReader in = new InputStreamReader(is); // FIXME - encoding
            char buffer[] = new char[BUFFER_SIZE];
            int n = 0;
            while (true) {
                n = in.read(buffer);
                if (n < 1)
                    break;
                sb.append(buffer, 0, n);
            }
            in.close();
        } catch (Exception e) {
            TagUtils.getInstance().saveException(pageContext, e);
            throw new JspException(
                messages.getMessage("include.read", url.toString(), e.toString()));
        }

        // Define the retrieved content as a page scope attribute
        pageContext.setAttribute(id, sb.toString());

        // Skip any body of this tag
        return (SKIP_BODY);
    }
    /**
     *  Add a session id cookie if appropriate. Can be overloaded to
     *  support a cluster.
     * @param conn
     * @param urlString
     * @param request
     * @since Struts 1.2.0
     */
    protected void addCookie(URLConnection conn, String urlString, HttpServletRequest request) {
        if ((conn instanceof HttpURLConnection)
            && urlString.startsWith(request.getContextPath())
            && (request.getRequestedSessionId() != null)
            && request.isRequestedSessionIdFromCookie()) {
            StringBuffer sb = new StringBuffer("JSESSIONID=");
            sb.append(request.getRequestedSessionId());
            conn.setRequestProperty("Cookie", sb.toString());
        }
    }

    /**
     * Release all allocated resources.
     */
    public void release() {
        super.release();
        anchor = null;
        forward = null;
        href = null;
        id = null;
        page = null;
        transaction = false;
    }    

}