Java tutorial
/** * Copyright (c) 2005-2012 springside.org.cn * * Licensed under the Apache License, Version 2.0 (the "License"); */ package cn.com.qiqi.order.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.StringUtils; import org.apache.commons.lang3.Validate; import org.springframework.data.domain.PageRequest; import org.springframework.data.domain.Pageable; import com.google.common.net.HttpHeaders; /** * HttpServlet. * * @author calvin */ public class Servlets { // -- --// public static final long ONE_YEAR_SECONDS = 60 * 60 * 24 * 365; /** * 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); } /** * ?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"); } /** * LastModified Header. */ public static void setLastModifiedHeader(HttpServletResponse response, long lastModifiedDate) { response.setDateHeader(HttpHeaders.LAST_MODIFIED, lastModifiedDate); } /** * Etag Header. */ public static void setEtag(HttpServletResponse response, String etag) { response.setHeader(HttpHeaders.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(HttpHeaders.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(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; } /** * ??Header. * * @param fileName ???. */ public static void setFileDownloadHeader(HttpServletResponse response, String fileName) { try { // ??? String encodedfileName = new String(fileName.getBytes(), "ISO8859-1"); response.setHeader(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=\"" + encodedfileName + "\""); } catch (UnsupportedEncodingException e) { } } /** * ???Request Parameters, copy from spring WebUtils. * * Parameter???. */ @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; } /** * ?Parameters?Query StringParameter, paramter nameprefix. * * @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(); } /** * Http Basic? Header?. */ public static String encodeHttpBasic(String userName, String password) { String encode = userName + ":" + password; return "Basic " + Encodes.encodeBase64(encode.getBytes()); } /** * ?Pageable * @param request * @return */ public static Pageable buildPageable(HttpServletRequest request) { String pageNo = StringUtils.defaultIfBlank(request.getParameter("page"), "0"); int page = Integer.parseInt(pageNo); String ps = StringUtils.defaultIfBlank(request.getParameter("pageSize"), "50"); int pageSize = Integer.parseInt(ps); Pageable pageable = new PageRequest(page, pageSize); return pageable; } }