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

Go to download

Show more of this group Show more artifacts with this name
Show all versions of dwr Show documentation

DWR is easy Ajax for Java. It makes it simple to call Java code directly from Javascript. It gets rid of almost all the boiler plate code between the web browser and your Java code.

The newest version!

/*
 * Copyright 2005 Joe Walker
 *
 * 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.directwebremoting.servlet;

import java.util.Date;

import javax.servlet.http.HttpServletRequest;
import javax.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, javax.servlet.http.HttpServletRequest, javax.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;
}