org.directwebremoting.servlet.PublicPeriodCacheableResponse Maven / Gradle / Ivy

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DWR is easy Ajax for Java. It makes it simple to call Java code directly from Javascript. It gets rid of almost all the boilerplate code between the web browser and your Java code. This version 4.0.2 works with Jakarta Servlet 4.0.2.

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package org.directwebremoting.servlet;

import java.util.Date;

import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;

import org.directwebremoting.extend.Handler;
import org.directwebremoting.util.LocalUtil;

/**
 * @author Mike Wilson
 */
public class PublicPeriodCacheableResponse implements ResponseHandler
{
    /* (non-Javadoc)
     * @see org.directwebremoting.servlet.ResponseHandler#handle(org.directwebremoting.extend.Handler, jakarta.servlet.http.HttpServletRequest, jakarta.servlet.http.HttpServletResponse)
     */
    public void handle(Handler handler, HttpServletRequest request, HttpServletResponse response)
    {
        if (periodCacheableSecs == 0)
        {
            LocalUtil.addNoCacheHeaders(response);
            return;
        }

        int cacheSecs;

        if (periodCacheableSecs < 0)
        {
            // Defaults
            if (debug)
            {
                cacheSecs = 1*60; // 1 minute
            }
            else
            {
                cacheSecs = 5*60; // 5 minutes
            }
        }
        else
        {
            // Explicit setting by developer
            cacheSecs = periodCacheableSecs;
        }

        long expiry = new Date().getTime() + cacheSecs*1000;

        // Set standard HTTP/1.1 cache headers.
        response.setHeader("Cache-Control", "public, max-age=" + cacheSecs);

        // Set to expire far in the past. Prevents caching at the proxy server
        response.setDateHeader("Expires", expiry);
    }

    public void setPeriodCacheableTime(int secs)
    {
        this.periodCacheableSecs = secs;
    }

    public void setDebug(boolean debug)
    {
        this.debug = debug;
    }

    private int periodCacheableSecs = -1;

    private boolean debug = false;
}