Java tutorial
/** * Copyright (c) 2005-2012 springside.org.cn * * Licensed under the Apache License, Version 2.0 (the "License"); */ package com.yiji.openapi.sdk.util; import com.google.common.collect.Lists; import com.google.common.collect.Maps; import com.google.common.net.HttpHeaders; import org.apache.commons.io.IOUtils; import org.apache.commons.lang3.StringUtils; import org.apache.commons.lang3.Validate; import org.springframework.http.MediaType; import javax.servlet.ServletRequest; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.ByteArrayInputStream; import java.io.InputStream; import java.io.OutputStream; import java.io.UnsupportedEncodingException; import java.nio.charset.Charset; import java.util.*; import java.util.Map.Entry; /** * HttpServlet. * */ public class Servlets { // -- --// public static final long ONE_YEAR_SECONDS = 60 * 60 * 24 * 365; public static void writeResponse(HttpServletResponse response, String data) { OutputStream output = null; InputStream input = null; try { response.setCharacterEncoding("UTF-8"); response.setContentType(MediaType.APPLICATION_JSON_VALUE); output = response.getOutputStream(); input = new ByteArrayInputStream(data.getBytes(Charset.forName("UTF-8"))); IOUtils.copy(input, output); output.flush(); } catch (Exception e) { throw new RuntimeException("?(flushResponse):" + e.getMessage()); } finally { IOUtils.closeQuietly(output); IOUtils.closeQuietly(input); } } /** * 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()); } /** * ?URL * * @param request * @return */ public static String getRequestPath(HttpServletRequest request) { return StringUtils.substringAfter(request.getRequestURI(), request.getContextPath()); } public static String getRequestPage(HttpServletRequest request) { return StringUtils.substringAfterLast(request.getRequestURI(), "/"); } public static String getRequestFullPath(HttpServletRequest request) { return getRequestPath(request) + "?" + request.getQueryString(); } public static String getHeaderValue(HttpServletRequest request, String name) { String value = request.getHeader(name); if (StringUtils.isBlank(value)) { value = request.getHeader(StringUtils.lowerCase(name)); } return value; } @SuppressWarnings("unchecked") public static List<String> getHeaderValues(HttpServletRequest request, String name) { Enumeration<String> e = request.getHeaders(name); List<String> values = Lists.newArrayList(); while (e.hasMoreElements()) { values.add(e.nextElement()); } return values; } @SuppressWarnings("unchecked") public static Map<String, String> getHeaders(HttpServletRequest request, String prefixName) { Enumeration<String> names = request.getHeaderNames(); String name = null; Map<String, String> map = Maps.newLinkedHashMap(); while (names.hasMoreElements()) { name = names.nextElement(); if (StringUtils.isNotBlank(prefixName)) { if (StringUtils.startsWithIgnoreCase(name, prefixName)) { map.put(StringUtils.lowerCase(name), getHeaderValue(request, name)); } } else { map.put(StringUtils.lowerCase(name), getHeaderValue(request, name)); } } return map; } public static void setHeader(HttpServletResponse response, String name, String value) { response.setHeader(name, value); } public static void setHeaders(HttpServletResponse response, Map<String, String> map) { for (Map.Entry<String, String> entry : map.entrySet()) { setHeader(response, entry.getKey(), entry.getValue()); } } public static String getQueryString(HttpServletRequest request) { return getRequestPath(request) + "?" + request.getQueryString(); } }