urlprocessor.java

Ajax 框架,可以用来做数型菜单或者联动下拉列表

                output = buffer.toString();

                if (mimeType.equals(MimeConstants.MIME_JS) && scriptCompressed)
                {
                    output = JavascriptUtil.compress(output, compressionLevel);
                }

                if (!dynamic)
                {
                    scriptCache.put(path, output);
                }
            }
        }

        response.setContentType(mimeType);
        response.setDateHeader(HttpConstants.HEADER_LAST_MODIFIED, servletContainerStartTime);
        response.setHeader(HttpConstants.HEADER_ETAG, etag);

        PrintWriter out = response.getWriter();
        out.println(output);
        out.flush();
    }

    /**
     * Do we need to send the conent for this file
     * @param req The HTTP request
     * @param path The file path (for debug purposes)
     * @return true iff the ETags and If-Modified-Since headers say we have not changed
     */
    private boolean isUpToDate(HttpServletRequest req, String path)
    {
        if (ignoreLastModified)
        {
            return false;
        }

        long modifiedSince = req.getDateHeader(HttpConstants.HEADER_IF_MODIFIED);
        if (modifiedSince != -1)
        {
            // Browsers are only accurate to the second
            modifiedSince -= modifiedSince % 1000;
        }
        String givenEtag = req.getHeader(HttpConstants.HEADER_IF_NONE);

        // Deal with missing etags
        if (givenEtag == null)
        {
            // There is no ETag, just go with If-Modified-Since
            if (modifiedSince > servletContainerStartTime)
            {
                if (log.isDebugEnabled())
                {
                    log.debug("Sending 304 for " + path + " If-Modified-Since=" + modifiedSince + ", Last-Modified=" + servletContainerStartTime); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
                }
                return true;
            }

            // There are no modified setttings, carry on
            return false;
        }

        // Deal with missing If-Modified-Since
        if (modifiedSince == -1)
        {
            if (!etag.equals(givenEtag))
            {
                // There is an ETag, but no If-Modified-Since
                if (log.isDebugEnabled())
                {
                    log.debug("Sending 304 for " + path + " Old ETag=" + givenEtag + ", New ETag=" + etag); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
                }
                return true;
            }

            // There are no modified setttings, carry on
            return false;
        }

        // Do both values indicate that we are in-date?
        if (etag.equals(givenEtag) && modifiedSince <= servletContainerStartTime)
        {
            if (log.isDebugEnabled())
            {
                log.debug("Sending 304 for " + path); //$NON-NLS-1$
            }
            return true;
        }

        return false;
    }

    /**
     * @param ignoreLastModified The ignoreLastModified to set.
     */
    public void setIgnoreLastModified(boolean ignoreLastModified)
    {
        this.ignoreLastModified = ignoreLastModified;
    }

    /**
     * To what level do we compress scripts?
     * @param scriptCompressed The scriptCompressed to set.
     */
    public void setScriptCompressed(boolean scriptCompressed)
    {
        this.scriptCompressed = scriptCompressed;
    }

    /**
     * @param compressionLevel The compressionLevel to set.
     */
    public void setCompressionLevel(int compressionLevel)
    {
        this.compressionLevel = compressionLevel;
    }

    /**
     * Setter for the remoter
     * @param remoter
     */
    public void setRemoter(Remoter remoter)
    {
        this.remoter = remoter;
    }

    /**
     *
     * @param debugPageGenerator
     */
    public void setDebugPageGenerator(DebugPageGenerator debugPageGenerator)
    {
        this.debugPageGenerator = debugPageGenerator;
    }

    /**
     * Setter for the Plain Javascript Marshaller
     * @param marshaller
     */
    public void setPlainJsMarshaller(DwrpPlainJsMarshaller marshaller)
    {
        this.plainJsMarshaller = marshaller;
    }

    /**
     * Setter for the HTML Javascript Marshaller
     * @param marshaller
     */
    public void setHtmlJsMarshaller(DwrpHtmlJsMarshaller marshaller)
    {
        this.htmlJsMarshaller = marshaller;
    }

    /**
     * Do we use our hack for when pathInfo is null?
     * @param nullPathInfoWorkaround The nullPathInfoWorkaround to set.
     */
    public void setNullPathInfoWorkaround(boolean nullPathInfoWorkaround)
    {
        this.nullPathInfoWorkaround = nullPathInfoWorkaround;
    }

    /**
     * The time on the script files
     */
    private static final long servletContainerStartTime;

    /**
     * The etag (=time for us) on the script files
     */
    private static final String etag;

    /**
     * Initialize the container start time
     */
    static
    {
        // Browsers are only accurate to the second
        long now = System.currentTimeMillis();
        servletContainerStartTime = now - (now % 1000);

        etag = "\"" + servletContainerStartTime + '\"'; //$NON-NLS-1$
    }

    /**
     * Do we use our hack for when pathInfo is null?
     * Enabling this will require you to have a / on the end of the DWR root URL
     */
    private boolean nullPathInfoWorkaround = false;

    /**
     * The page id length
     */
    private int pageIdLength = 16;

    /**
     * The method by which we get new page ids
     */
    private IdGenerator generator = new IdGenerator();

    /**
     * Do we ignore all the Last-Modified/ETags blathering?
     */
    private boolean ignoreLastModified = false;

    /**
     * How much do we compression javascript by?
     */
    private int compressionLevel = JavascriptUtil.LEVEL_DEBUGGABLE;

    /**
     * Do we retain comments and unneeded spaces in Javascript code?
     */
    private boolean scriptCompressed = true;

    /**
     * We cache the script output for speed
     */
    private final Map scriptCache = new HashMap();

    /**
     * The bean to handle debug page requests
     */
    private DebugPageGenerator debugPageGenerator = null;

    /**
     * The 'HTML Javascript' method by which objects are marshalled
     */
    private DwrpPlainJsMarshaller plainJsMarshaller = null;

    /**
     * The 'Plain Javascript' method by which objects are marshalled
     */
    private DwrpHtmlJsMarshaller htmlJsMarshaller = null;

    /**
     * The bean to execute remote requests and generate interfaces
     */
    private Remoter remoter = null;

    /**
     * The session id parameter that goes in engine.js
     */
    private static final String PARAM_HTTP_SESSIONID = "${httpSessionId}"; //$NON-NLS-1$

    /**
     * The page id parameter that goes in engine.js
     */
    private static final String PARAM_SCRIPT_SESSIONID = "${scriptSessionId}"; //$NON-NLS-1$

    /**
     * The log stream
     */
    private static final Logger log = Logger.getLogger(UrlProcessor.class);
}