package com.mossle.core.util;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
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;
/**
* servlet utils.
*
* @author Lingo
*/
public class ServletUtils {
// -- Content Type 定义 --//
/** text type. */
public static final String TEXT_TYPE = "text/plain";
/** json type. */
public static final String JSON_TYPE = "application/json";
/** xml type. */
public static final String XML_TYPE = "text/xml";
/** html type. */
public static final String HTML_TYPE = "text/html";
/** js type. */
public static final String JS_TYPE = "text/javascript";
/** excel type. */
public static final String EXCEL_TYPE = "application/vnd.ms-excel";
/** stream type. */
public static final String STREAM_TYPE = "application/octet-stream";
// -- Header 定义 --//
/** authencation header. */
public static final String AUTHENTICATION_HEADER = "Authorization";
// -- 常用数值定义 --//
/** one year seconds. */
public static final long ONE_YEAR_SECONDS = 60 * 60 * 24 * 365;
/** mill seconds. */
public static final int MILL_SECONDS = 1000;
/** protected constructor. */
protected ServletUtils() {
}
/**
* 设置客户端缓存过期时间的Header.
*
* @param response
* HttpServletResponse
* @param expiresSeconds
* long
*/
public static void setExpiresHeader(HttpServletResponse response,
long expiresSeconds) {
// Http 1.0 header
response.setDateHeader("Expires", System.currentTimeMillis()
+ (expiresSeconds * MILL_SECONDS));
// Http 1.1 header
response.setHeader("Cache-Control", "private, max-age="
+ expiresSeconds);
}
/**
* 设置禁止客户端缓存的Header.
*
* @param response
* HttpServletResponse
*/
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");
}
/**
* 设置LastModified Header.
*
* @param response
* HttpServletResponse
* @param lastModifiedDate
* long
*/
public static void setLastModifiedHeader(HttpServletResponse response,
long lastModifiedDate) {
response.setDateHeader("Last-Modified", lastModifiedDate);
}
/**
* 设置Etag Header.
*
* @param response
* HttpServletResponse
* @param etag
* String
*/
public static void setEtag(HttpServletResponse response, String etag) {
response.setHeader("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 request
* HttpServletRequest
* @param response
* HttpServletResponse
* @param lastModified
* 内容的最后修改时间.
* @return boolean
*/
public static boolean checkIfModifiedSince(HttpServletRequest request,
HttpServletResponse response, long lastModified) {
long ifModifiedSince = request.getDateHeader("If-Modified-Since");
if ((ifModifiedSince != -1)
&& (lastModified < (ifModifiedSince + MILL_SECONDS))) {
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 request
* HttpServletRequest
* @param response
* HttpServletResponse
* @param etag
* 内容的ETag.
* @return boolean
*/
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;
}
/**
* 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(HttpServletRequest request,
HttpServletResponse response, String fileName)
throws UnsupportedEncodingException {
// 中文文件名支持
String encodedFileName = null;
// 替换空格，否则firefox下有空格文件名会被截断,其他浏览器会将空格替换成+号
encodedFileName = fileName.trim().replaceAll(" ", "_");
String agent = request.getHeader("User-Agent");
boolean isMSIE = ((agent != null) && (agent.toUpperCase().indexOf(
"MSIE") != -1));
if (isMSIE) {
encodedFileName = URLEncoder.encode(encodedFileName, "UTF-8");
} else {
encodedFileName = new String(fileName.getBytes("UTF-8"),
"ISO8859-1");
}
response.setHeader("Content-Disposition", "attachment; filename=\""
+ encodedFileName + "\"");
}
/**
* 取得带相同前缀的Request Parameters. 返回的结果的Parameter名已去除前缀.
*
* @param request
* HttpServletRequest
* @param prefix
* String
* @return Map
*/
@SuppressWarnings("unchecked")
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>();
String thePrefix = (prefix == null) ? "" : prefix;
while (paramNames.hasMoreElements()) {
String paramName = (String) paramNames.nextElement();
if ("".equals(thePrefix) || paramName.startsWith(thePrefix)) {
String unprefixed = paramName.substring(thePrefix.length());
String[] values = request.getParameterValues(paramName);
if ((values == null) || (values.length == 0)) {
// Do nothing, no values found at all.
continue;
}
if (values.length > 1) {
params.put(unprefixed, values);
} else {
params.put(unprefixed, values[0]);
}
}
}
return params;
}
public static Map<String, Object> getParametersStartingWith(
Map<String, Object> parameterMap, String prefix) {
Map<String, Object> params = new TreeMap<String, Object>();
String thePrefix = (prefix == null) ? "" : prefix;
for (Map.Entry<String, Object> entry : parameterMap.entrySet()) {
String paramName = entry.getKey();
Object paramValue = entry.getValue();
if ("".equals(thePrefix) || paramName.startsWith(thePrefix)) {
String unprefixed = paramName.substring(thePrefix.length());
if (paramValue == null) {
// Do nothing, no values found at all.
continue;
}
params.put(unprefixed, paramValue);
}
}
return params;
}
/**
* 对Http Basic验证的 Header进行编码.
*
* @param userName
* String
* @param password
* String
* @return String
*/
public static String encodeHttpBasic(String userName, String password)
throws UnsupportedEncodingException {
String encode = userName + ":" + password;
return "Basic " + EncodeUtils.base64Encode(encode.getBytes("UTF-8"));
}
}