Java tutorial
/** * Copyright (c) 2005-2012 springside.org.cn * * Licensed under the Apache License, Version 2.0 (the "License"); */ package net.turnbig.pandora.web; import java.io.IOException; import java.io.UnsupportedEncodingException; import java.net.URLEncoder; import java.util.Enumeration; import java.util.Iterator; import java.util.List; import java.util.Map; import java.util.Map.Entry; import java.util.StringTokenizer; import java.util.TreeMap; import javax.servlet.ServletOutputStream; import javax.servlet.ServletRequest; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.lang3.StringUtils; import org.springframework.http.HttpHeaders; import com.google.common.collect.Lists; import net.turnbig.pandora.utils.Collections3; import net.turnbig.pandora.utils.Encodes; /** * 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(HttpServletRequest request, HttpServletResponse response, String fileName) { try { String agent = request.getHeader("User-Agent"); boolean isMSIE = ((agent != null) && (agent.indexOf("MSIE") != -1)); String encoded = isMSIE ? URLEncoder.encode(fileName, "UTF-8") : new String(fileName.getBytes("UTF-8"), "ISO-8859-1"); response.setHeader(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=\"" + encoded + "\""); } catch (UnsupportedEncodingException e) { } } /** * ???Request Parameters, copy from spring WebUtils. * * Parameter???. */ public static Map<String, Object> getParametersStartingWith(ServletRequest request, String prefix) { Enumeration paramNames = request.getParameterNames(); Map<String, Object> params = new TreeMap<String, Object>(); String prefix_ = 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; } /** * ?Request Parameters, copy from spring WebUtils. * * Parameter */ @SuppressWarnings("rawtypes") public static Map<String, Object> getParameters(ServletRequest request) { Enumeration paramNames = request.getParameterNames(); Map<String, Object> params = new TreeMap<String, Object>(); while ((paramNames != null) && paramNames.hasMoreElements()) { String paramName = (String) paramNames.nextElement(); 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(paramName, values); } else { params.put(paramName, 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 ""; } String prefix_ = prefix == null ? "" : prefix; List<String> list = Lists.newArrayList(); Iterator<Entry<String, Object>> it = params.entrySet().iterator(); while (it.hasNext()) { Entry<String, Object> entry = it.next(); Object values = entry.getValue(); if (values instanceof String[]) { for (String v : (String[]) values) { list.add(String.format("%s%s=%s", prefix_, entry.getKey(), v)); } } else if (values instanceof String) { list.add(String.format("%s%s=%s", prefix_, entry.getKey(), values)); } } return Collections3.convertToString(list, "&"); } /** * Http Basic? Header?. */ public static String encodeHttpBasic(String userName, String password) { String encode = userName + ":" + password; return "Basic " + Encodes.encodeBase64(encode.getBytes()); } /** * http://domain:port/context/related-path * * @param request * @return http://domain:port/context */ public static String getBasePath(HttpServletRequest request) { String requestURL = request.getRequestURL().toString(); // whole URL String requestURI = request.getRequestURI(); // context-path + path String host = StringUtils.substringBeforeLast(requestURL, requestURI); String contextPath = request.getContextPath(); return StringUtils.removeEnd(host + contextPath, "/"); } /** * * http://domain:port/context/related-path * * @param request * @return related-path */ public static String getRelatedpath(HttpServletRequest request) { String requestURI = request.getRequestURI(); // context-path + path String contextPath = request.getContextPath(); return StringUtils.removeStart(requestURI, contextPath); } public static String getHost(HttpServletRequest request) { String requestURL = request.getRequestURL().toString(); String requestURI = request.getRequestURI(); String host = StringUtils.substringBefore(requestURL, requestURI); return host; } public static String getIp(HttpServletRequest request) { String xforward = request.getHeader("x-forwarded-for"); // TODO shall we use a more reliable solution? // compare xforward with haproxy ip if (StringUtils.isNotEmpty(xforward)) { String[] split = StringUtils.split(xforward, "."); if (split.length == 4) { return xforward; } } return request.getRemoteAddr(); } public static void output(HttpServletResponse response, String contentType, Object content) throws IOException { ServletOutputStream output = response.getOutputStream(); try { response.setContentType(contentType); if (content instanceof byte[]) { byte[] temp = (byte[]) content; output.write(temp); } else if (content instanceof String) { output.print(String.valueOf(content)); } } finally { output.flush(); output.close(); } } }