com.hysd.util.ServletUtils.java Source code

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Here is the source code for com.hysd.util.ServletUtils.java

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/**
 * Copyright (c) 2005-2010 springside.org.cn
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * 
 * $Id: ServletUtils.java 1211 2010-09-10 16:20:45Z calvinxiu $
 */
package com.hysd.util;

import java.io.UnsupportedEncodingException;
import java.util.Enumeration;
import java.util.Map;
import java.util.StringTokenizer;
import java.util.TreeMap;

import javax.servlet.ServletRequest;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.util.Assert;

/**
 * HttpServlet.
 * 
 */
public class ServletUtils {

    // -- Content Type  --//
    public static final String TEXT_TYPE = "text/plain";
    public static final String JSON_TYPE = "application/json";
    public static final String XML_TYPE = "text/xml";
    public static final String HTML_TYPE = "text/html";
    public static final String JS_TYPE = "text/javascript";
    public static final String EXCEL_TYPE = "application/vnd.ms-excel";

    // -- Header  --//
    public static final String AUTHENTICATION_HEADER = "Authorization";

    // --  --//
    public static final long ONE_YEAR_SECONDS = 60 * 60 * 24 * 365;

    /**
     *  Header.
     */
    public static void setExpiresHeader(HttpServletResponse response, long expiresSeconds) {
        // Http 1.0 header
        response.setDateHeader("Expires", System.currentTimeMillis() + expiresSeconds * 1000);
        // Http 1.1 header
        response.setHeader("Cache-Control", "private, max-age=" + expiresSeconds);
    }

    /**
     * ?Header.
     */
    public static void setDisableCacheHeader(HttpServletResponse response) {
        // Http 1.0 header
        response.setDateHeader("Expires", 1L);
        response.addHeader("Pragma", "no-cache");
        // Http 1.1 header
        response.setHeader("Cache-Control", "no-cache, no-store, max-age=0");
    }

    /**
     * LastModified Header.
     */
    public static void setLastModifiedHeader(HttpServletResponse response, long lastModifiedDate) {
        response.setDateHeader("Last-Modified", lastModifiedDate);
    }

    /**
     * Etag Header.
     */
    public static void setEtag(HttpServletResponse response, String etag) {
        response.setHeader("ETag", etag);
    }

    /**
     * ??If-Modified-Since Header, ?.
     * 
     * , checkIfModifyfalse ,304 not modify status.
     * 
     * @param lastModified
     *            ?.
     */
    public static boolean checkIfModifiedSince(HttpServletRequest request, HttpServletResponse response,
            long lastModified) {
        long ifModifiedSince = request.getDateHeader("If-Modified-Since");
        if ((ifModifiedSince != -1) && (lastModified < ifModifiedSince + 1000)) {
            response.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
            return false;
        }
        return true;
    }

    /**
     * ?? If-None-Match Header, Etag?.
     * 
     * Etag, checkIfNoneMatchfalse, 304 not modify status.
     * 
     * @param etag
     *            ETag.
     */
    public static boolean checkIfNoneMatchEtag(HttpServletRequest request, HttpServletResponse response,
            String etag) {
        String headerValue = request.getHeader("If-None-Match");
        if (headerValue != null) {
            boolean conditionSatisfied = false;
            if (!"*".equals(headerValue)) {
                StringTokenizer commaTokenizer = new StringTokenizer(headerValue, ",");

                while (!conditionSatisfied && commaTokenizer.hasMoreTokens()) {
                    String currentToken = commaTokenizer.nextToken();
                    if (currentToken.trim().equals(etag)) {
                        conditionSatisfied = true;
                    }
                }
            } else {
                conditionSatisfied = true;
            }

            if (conditionSatisfied) {
                response.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
                response.setHeader("ETag", etag);
                return false;
            }
        }
        return true;
    }

    /**
     * ??Header.
     * 
     * @param fileName
     *            ???.
     */
    public static void setFileDownloadHeader(HttpServletResponse response, String fileName) {
        try {
            // ???
            String encodedfileName = new String(fileName.getBytes(), "ISO8859-1");
            response.setHeader("Content-Disposition", "attachment; filename=\"" + encodedfileName + "\"");
        } catch (UnsupportedEncodingException e) {
        }
    }

    /**
     * ???Request Parameters.
     * 
     * Parameter???.
     */

    @SuppressWarnings("rawtypes")
    public static Map<String, Object> getParametersStartingWith(ServletRequest request, String prefix) {
        Assert.notNull(request, "Request must not be null");

        Enumeration paramNames = request.getParameterNames();
        Map<String, Object> params = new TreeMap<String, Object>();
        if (prefix == null) {
            prefix = "";
        }
        while (paramNames != null && paramNames.hasMoreElements()) {
            String paramName = (String) paramNames.nextElement();
            if ("".equals(prefix) || paramName.startsWith(prefix)) {
                String unprefixed = paramName.substring(prefix.length());
                String[] values = request.getParameterValues(paramName);
                if (values == null || values.length == 0) {
                    // Do nothing, no values found at all.
                } else if (values.length > 1) {
                    params.put(unprefixed, values);
                } else {
                    params.put(unprefixed, values[0]);
                }
            }
        }
        return params;
    }
}