/**
* Copyright (c) 2005-2012 springside.org.cn
*
* Licensed under the Apache License, Version 2.0 (the "License");
*/
package com.sobey.framework.utils;
import java.io.UnsupportedEncodingException;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;
import java.util.StringTokenizer;
import java.util.TreeMap;
import javax.servlet.ServletRequest;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.lang3.Validate;
import com.google.common.net.HttpHeaders;
/**
* Http与Servlet工具类.
*
* @author calvin
*/
public class Servlets {
// -- 常用数值定义 --//
public static final long ONE_YEAR_SECONDS = 60 * 60 * 24 * 365;
/**
* 设置客户端缓存过期时间 的Header.
*/
public static void setExpiresHeader(HttpServletResponse response, long expiresSeconds) {
// Http 1.0 header, set a fix expires date.
response.setDateHeader(HttpHeaders.EXPIRES, System.currentTimeMillis() + expiresSeconds * 1000);
// Http 1.1 header, set a time after now.
response.setHeader(HttpHeaders.CACHE_CONTROL, "private, max-age=" + expiresSeconds);
}
/**
* 设置禁止客户端缓存的Header.
*/
public static void setNoCacheHeader(HttpServletResponse response) {
// Http 1.0 header
response.setDateHeader(HttpHeaders.EXPIRES, 1L);
response.addHeader(HttpHeaders.PRAGMA, "no-cache");
// Http 1.1 header
response.setHeader(HttpHeaders.CACHE_CONTROL, "no-cache, no-store, max-age=0");
}
/**
* 设置LastModified Header.
*/
public static void setLastModifiedHeader(HttpServletResponse response, long lastModifiedDate) {
response.setDateHeader(HttpHeaders.LAST_MODIFIED, lastModifiedDate);
}
/**
* 设置Etag Header.
*/
public static void setEtag(HttpServletResponse response, String etag) {
response.setHeader(HttpHeaders.ETAG, etag);
}
/**
* 根据浏览器If-Modified-Since Header, 计算文件是否已被修改.
*
* 如果无修改, checkIfModify返回false ,设置304 not modify status.
*
* @param lastModified
* 内容的最后修改时间.
*/
public static boolean checkIfModifiedSince(HttpServletRequest request, HttpServletResponse response,
long lastModified) {
long ifModifiedSince = request.getDateHeader(HttpHeaders.IF_MODIFIED_SINCE);
if ((ifModifiedSince != -1) && (lastModified < ifModifiedSince + 1000)) {
response.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
return false;
}
return true;
}
/**
* 根据浏览器 If-None-Match Header, 计算Etag是否已无效.
*
* 如果Etag有效, checkIfNoneMatch返回false, 设置304 not modify status.
*
* @param etag
* 内容的ETag.
*/
public static boolean checkIfNoneMatchEtag(HttpServletRequest request, HttpServletResponse response, String etag) {
String headerValue = request.getHeader(HttpHeaders.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(HttpHeaders.ETAG, etag);
return false;
}
}
return true;
}
/**
* 设置让浏览器弹出下载对话框的Header.
*
* @param fileName
* 下载后的文件名.
*/
public static void setFileDownloadHeader(HttpServletResponse response, String fileName) {
try {
// 中文文件名支持
String encodedfileName = new String(fileName.getBytes(), "ISO8859-1");
response.setHeader(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=\"" + encodedfileName + "\"");
} catch (UnsupportedEncodingException e) {
}
}
/**
* 取得带相同前缀的Request Parameters, copy from spring WebUtils.
*
* 返回的结果的Parameter名已去除前缀.
*/
@SuppressWarnings("rawtypes")
public static Map<String, Object> getParametersStartingWith(ServletRequest request, String prefix) {
Validate.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;
}
/**
* 组合Parameters生成Query String的Parameter部分, 并在paramter name上加上prefix.
*
* @see #getParametersStartingWith
*/
public static String encodeParameterStringWithPrefix(Map<String, Object> params, String prefix) {
if (params == null || params.size() == 0) {
return "";
}
if (prefix == null) {
prefix = "";
}
StringBuilder queryStringBuilder = new StringBuilder();
Iterator<Entry<String, Object>> it = params.entrySet().iterator();
while (it.hasNext()) {
Entry<String, Object> entry = it.next();
queryStringBuilder.append(prefix).append(entry.getKey()).append('=').append(entry.getValue());
if (it.hasNext()) {
queryStringBuilder.append('&');
}
}
return queryStringBuilder.toString();
}
/**
* 客户端对Http Basic验证的 Header进行编码.
*/
public static String encodeHttpBasic(String userName, String password) {
String encode = userName + ":" + password;
return "Basic " + Encodes.encodeBase64(encode.getBytes());
}
}