Admin: 1 версия

2010-06-01T06:11:45Z

1 версия

в 18:01, 31 мая 2010

2010-05-31T18:01:43Z

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== Browser detection ==



<source lang="java">

/*
* Copyright 2005 Joe Walker
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import javax.servlet.http.HttpServletRequest;

/**
* Various functions to do with working out what is at the other end of the
* wire, and what it can do.
*
* <h2>Version number documentation</h2>
*
* <h3>Safari</h3>
* <p>Quick summary:
* <ul>
* <li>Jaguar = 10.2.x = Safari 1.0.x = WebKit/85
* <li>Panther = 10.3.0+ = Safari 1.1.x = WebKit/100
* <li>Panther = 10.3.4+ = Safari 1.2.x = WebKit/125
* <li>Panther = 10.3.9+ = Safari 1.3.x = WebKit/312
* <li>Tiger = 10.4.x = Safari 2.0.x = WebKit/412-419
* <li>Tiger = 10.4.11 = Safari 3.0.x = WebKit/523
* <li>Leopard = 10.5.x = Safari 3.0.x = WebKit/523
* <li>Windows = Safari 3.0.x = WebKit/523
* <li>Leopard = 10.5.x = Safari 3.1.x = WebKit/525-526
* </ul>
*
* <p>For full information see the Safari and WebKit Version Information:
* .</p>
* @author Joe Walker [joe at getahead dot ltd dot uk]
*/
public class BrowserDetect
{
/**
* How many connections can this browser open simultaneously?
* @param request The request so we can get at the user-agent header
* @return The number of connections that we think this browser can take
*/
public static int getConnectionLimit(HttpServletRequest request)
{
if (atLeast(request, UserAgent.IE, 8))
{
return 6;
}
else if (atLeast(request, UserAgent.AppleWebKit, 8))
{
return 4;
}
else if (atLeast(request, UserAgent.Opera, 9))
{
return 4;
}
else
{
return 2;
}
}
/**
* Does this web browser support comet?
* @param request The request so we can get at the user-agent header
* @return True if long lived HTTP connections are supported
*/
public static boolean supportsComet(HttpServletRequest request)
{
String userAgent = request.getHeader("user-agent");
// None of the non-iPhone mobile browsers that I"ve tested support comet
if (userAgent.contains("Symbian"))
{
return false;
}
// We need to test for other failing browsers here
return true;
}
/**
* Check that the user-agent string indicates some minimum browser level
* @param request The browsers request
* @param requiredUserAgent The UA required
* @return true iff the browser matches the spec.
*/
public static boolean atLeast(HttpServletRequest request, UserAgent requiredUserAgent)
{
return atLeast(request, requiredUserAgent, -1);
}
/**
* Check that the user-agent string indicates some minimum browser level
* @param request The browsers request
* @param requiredUserAgent The UA required. Currently this is major version only
* @param requiredVersion The version required, or -1 if versions are not important
* @return true iff the browser matches the spec.
*/
public static boolean atLeast(HttpServletRequest request, UserAgent requiredUserAgent, int requiredVersion)
{
String userAgent = request.getHeader("user-agent");
int realVersion;
switch (requiredUserAgent)
{
case IE:
realVersion = getMajorVersionAssumingIE(userAgent);
break;
case Gecko:
realVersion = getMajorVersionAssumingGecko(userAgent);
break;
case Opera:
realVersion = getMajorVersionAssumingOpera(userAgent);
break;
case AppleWebKit:
realVersion = getMajorVersionAssumingAppleWebKit(userAgent);
break;
default:
throw new UnsupportedOperationException("Detection of " + requiredUserAgent + " is not supported yet.");
}
return realVersion >= requiredVersion;
}
/**
* Check {@link #atLeast(HttpServletRequest, UserAgent)} for
* {@link UserAgent#AppleWebKit}
*/
private static int getMajorVersionAssumingAppleWebKit(String userAgent)
{
int webKitPos = userAgent.indexOf("AppleWebKit");
if (webKitPos == -1)
{
return -1;
}
return parseNumberAtStart(userAgent.substring(webKitPos + 12));
}
/**
* Check {@link #atLeast(HttpServletRequest, UserAgent)} for
* {@link UserAgent#Opera}
*/
private static int getMajorVersionAssumingOpera(String userAgent)
{
int operaPos = userAgent.indexOf("Opera");
if (operaPos == -1)
{
return -1;
}
return parseNumberAtStart(userAgent.substring(operaPos + 6));
}
/**
* Check {@link #atLeast(HttpServletRequest, UserAgent)} for
* {@link UserAgent#Gecko}
*/
private static int getMajorVersionAssumingGecko(String userAgent)
{
int geckoPos = userAgent.indexOf(" Gecko/20");
if (geckoPos == -1 || userAgent.contains("WebKit/"))
{
return -1;
}
return parseNumberAtStart(userAgent.substring(geckoPos + 7));
}
/**
* Check {@link #atLeast(HttpServletRequest, UserAgent)} for
* {@link UserAgent#IE}
*/
private static int getMajorVersionAssumingIE(String userAgent)
{
int msiePos = userAgent.indexOf("MSIE ");
if (msiePos == -1 || userAgent.contains("Opera"))
{
return -1;
}
return parseNumberAtStart(userAgent.substring(msiePos + 5));
}
/**
* We"ve found the start of a sequence of numbers, what is it as an int?
*/
private static int parseNumberAtStart(String numberString)
{
if (numberString == null || numberString.length() == 0)
{
return -1;
}
int endOfNumbers = 0;
while (Character.isDigit(numberString.charAt(endOfNumbers)))
{
endOfNumbers++;
}
try
{
return Integer.parseInt(numberString.substring(0, endOfNumbers));
}
catch (NumberFormatException ex)
{
return -1;
}
}
/**
* This method is for debugging only
*/
public static String getUserAgentDebugString(HttpServletRequest request)
{
String userAgent = request.getHeader("user-agent");
int version = getMajorVersionAssumingIE(userAgent);
if (version != -1)
{
return "IE/" + version;
}
version = getMajorVersionAssumingGecko(userAgent);
if (version != -1)
{
return "Gecko/" + version;
}
version = getMajorVersionAssumingAppleWebKit(userAgent);
if (version != -1)
{
return "WebKit/" + version;
}
version = getMajorVersionAssumingOpera(userAgent);
if (version != -1)
{
return "Opera/" + version;
}
return "Unknown: (" + userAgent + ")";
}

}
/*
* Copyright 2005 Joe Walker
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @author Joe Walker [joe at getahead dot ltd dot uk]
*/
enum UserAgent
{
IE,
Opera,
Gecko,
AppleWebKit,
}

</source>



== Example servlet showing request headers ==



<source lang="java">

/*
* Copyright 2004 The Apache Software Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/* $Id: CookieExample.java,v 1.3 2004/03/18 16:40:33 jfarcand Exp $
*
*/
import java.io.*;
import java.text.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
/**
* Example servlet showing request headers
*
* @author James Duncan Davidson <duncan@eng.sun.ru>
*/
public class CookieExample extends HttpServlet {
ResourceBundle rb = ResourceBundle.getBundle("LocalStrings");

public void doGet(HttpServletRequest request,
HttpServletResponse response)
throws IOException, ServletException
{
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out.println("<html>");
out.println("<body bgcolor=\"white\">");
out.println("<head>");
String title = rb.getString("cookies.title");
out.println("<title>" + title + "</title>");
out.println("</head>");
out.println("<body>");
// relative links
// XXX
// making these absolute till we work out the
// addition of a PathInfo issue

out.println("");
out.println("<h3>" + title + "</h3>");
Cookie[] cookies = request.getCookies();
if ((cookies != null) && (cookies.length > 0)) {
out.println(rb.getString("cookies.cookies") + "<br>");
for (int i = 0; i < cookies.length; i++) {
Cookie cookie = cookies[i];
out.print("Cookie Name: " + HTMLFilter.filter(cookie.getName())
+ "<br>");
out.println(" Cookie Value: "
+ HTMLFilter.filter(cookie.getValue())
+ "<br><br>");
}
} else {
out.println(rb.getString("cookies.no-cookies"));
}
String cookieName = request.getParameter("cookiename");
String cookieValue = request.getParameter("cookievalue");
if (cookieName != null && cookieValue != null) {
Cookie cookie = new Cookie(cookieName, cookieValue);
response.addCookie(cookie);
out.println("<P>");
out.println(rb.getString("cookies.set") + "<br>");
out.print(rb.getString("cookies.name") + " "
+ HTMLFilter.filter(cookieName) + "<br>");
out.print(rb.getString("cookies.value") + " "
+ HTMLFilter.filter(cookieValue));
}

out.println("<P>");
out.println(rb.getString("cookies.make-cookie") + "<br>");
out.print("<form action=\"");
out.println("CookieExample\" method=POST>");
out.print(rb.getString("cookies.name") + " ");
out.println("<input type=text length=20 name=cookiename><br>");
out.print(rb.getString("cookies.value") + " ");
out.println("<input type=text length=20 name=cookievalue><br>");
out.println("<input type=submit></form>");

out.println("</body>");
out.println("</html>");
}
public void doPost(HttpServletRequest request,
HttpServletResponse response)
throws IOException, ServletException
{
doGet(request, response);
}
}

</source>



== Get Cookie from Request ==



<source lang="java">

import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class Cookies extends HttpServlet {
public void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException,
IOException {
resp.setContentType("text/html");
req.getSession();
PrintWriter out = resp.getWriter();
Cookie cookies[] = req.getCookies();
out.println("<html>");
out.println("<head>");
out.println("<title>Servlet Cookie Information</title>");
out.println("</head>");
out.println("<body>");
if ((cookies == null) || (cookies.length == 0)) {
out.println("<center><h1>No Cookies found</h1>");
} else {
out.println("<center><h1>Cookies found</h1>");
out.println("<table border>");
out.println("<tr><th>Name</th><th>Value</th>" + "<th>Comment</th><th>Max Age</th></tr>");
for (int i = 0; i < cookies.length; i++) {
Cookie c = cookies[i];
out.println("<tr><td>" + c.getName() + "</td><td>" + c.getValue() + "</td><td>"
+ c.getComment() + "</td><td>" + c.getMaxAge() + "</td></tr>");
}
out.println("</table></center>");
}
out.println("</body>");
out.println("</html>");
out.flush();
}
}

</source>



== Get Locale Information from Request ==



<source lang="java">

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Enumeration;
import java.util.Locale;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class LocaleInformationServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException,
ServletException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
Locale userPreferredLocale = request.getLocale();
Enumeration userPreferredLocales = request.getLocales();
out.println("Preferred Locale: " + userPreferredLocale.toString());
out.println("");
out.print("Preferred Locales: ");
while (userPreferredLocales.hasMoreElements()) {
userPreferredLocale = (Locale) userPreferredLocales.nextElement();
out.print(userPreferredLocale.toString() + ", ");
}
out.println();
out.println("");
}
}

</source>



== Get session from request ==



<source lang="java">

import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
public class Counter extends HttpServlet {
static final String COUNTER_KEY = "Counter.count";
public void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException,
IOException {
HttpSession session = req.getSession(true);
resp.setContentType("text/html");
PrintWriter out = resp.getWriter();
int count = 1;
Integer i = (Integer) session.getAttribute(COUNTER_KEY);
if (i != null) {
count = i.intValue() + 1;
}
session.setAttribute(COUNTER_KEY, new Integer(count));
out.println("<html>");
out.println("<head>");
out.println("<title>Session Counter</title>");
out.println("</head>");
out.println("<body>");
out.println("Your session ID is <b>" + session.getId());
out.println("</b> and you have hit this page <b>" + count
+ "</b> time(s) during this browser session");
out.println("<form method=GET action=\"" + req.getRequestURI() + "\">");
out.println("<input type=submit " + "value=\"Hit page again\">");
out.println("</form>");
out.println("</body>");
out.println("</html>");
out.flush();
}
}

</source>



== javax.servlet.request.X509Certificate ==



<source lang="java">

import java.io.IOException;
import java.io.PrintWriter;
import java.security.cert.X509Certificate;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class X509Snoop extends HttpServlet {
public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException,
IOException {
res.setContentType("text/plain");
PrintWriter out = res.getWriter();
X509Certificate[] certs = (X509Certificate[]) req
.getAttribute("javax.servlet.request.X509Certificate");
if (certs != null) {
for (int i = 0; i < certs.length; i++) {
out.println("Client Certificate [" + i + "] = " + certs[i].toString());
}
} else {
if ("https".equals(req.getScheme())) {
out.println("This was an HTTPS request, " + "but no client certificate is available");
} else {
out.println("This was not an HTTPS request, " + "so no client certificate is available");
}
}
}
}

</source>



== Request handling utility class ==



<source lang="java">

/*
* $Id: RequestUtils.java 651946 2008-04-27 13:41:38Z apetrelli $
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/

import javax.servlet.http.HttpServletRequest;

/**
* Request handling utility class.
*/
public class RequestUtils {
/**
* Retrieves the current request servlet path.
* Deals with differences between servlet specs (2.2 vs 2.3+)
*
* @param request the request
* @return the servlet path
*/
public static String getServletPath(HttpServletRequest request) {
String servletPath = request.getServletPath();

String requestUri = request.getRequestURI();
// Detecting other characters that the servlet container cut off (like anything after ";")
if (requestUri != null && servletPath != null && !requestUri.endsWith(servletPath)) {
int pos = requestUri.indexOf(servletPath);
if (pos > -1) {
servletPath = requestUri.substring(requestUri.indexOf(servletPath));
}
}

if (null != servletPath && !"".equals(servletPath)) {
return servletPath;
}

int startIndex = request.getContextPath().equals("") ? 0 : request.getContextPath().length();
int endIndex = request.getPathInfo() == null ? requestUri.length() : requestUri.lastIndexOf(request.getPathInfo());
if (startIndex > endIndex) { // this should not happen
endIndex = startIndex;
}
return requestUri.substring(startIndex, endIndex);
}
}

</source>



== Returns any parameters and lists server properties. ==



<source lang="java">

import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class Properties extends HttpServlet {
public void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException,
IOException {
PrintWriter out = resp.getWriter();
out.println("<html>");
out.println("<center><table>");
out.println("<tr>");
out.println("<td>Method</td>");
out.println("<td>" + req.getMethod() + "</td>");
out.println("</tr>");
out.println("<tr>");
out.println("<td>User</td>");
out.println("<td>" + req.getRemoteUser() + "</td>");
out.println("</tr>");
out.println("<tr>");
out.println("<td>Client</td>");
out.println("<td>" + req.getRemoteHost() + "</td>");
out.println("</tr>");
out.println("<tr>");
out.println("<td>Protocol</td>");
out.println("<td>" + req.getProtocol() + "</td>");
out.println("</tr>");
java.util.Enumeration e = req.getParameterNames();
while (e.hasMoreElements()) {
String name = (String) e.nextElement();
out.println("<tr>");
out.println("<td>Parameter "" + name + ""</td>");
out.println("<td>" + req.getParameter(name) + "</td>");
out.println("</tr>");
}
out.println("</table></center><br><hr><br>");
out.println("<h2><center>");
out.println("Server Properties</center></h2>");
out.println("<br>");
out.println("<center><table>");
java.util.Properties props = System.getProperties();
e = props.propertyNames();
while (e.hasMoreElements()) {
String name = (String) e.nextElement();
out.println("<tr>");
out.println("<td>" + name + "</td>");
out.println("<td>" + props.getProperty(name) + "</td>");
out.println("</tr>");
}
out.println("</table></center>");
out.println("</html>");
out.flush();
}
public void init() throws ServletException {
ServletConfig config = getServletConfig();
}
public void destroy() {
}
}

</source>



== Using Request Object Servlet ==

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Java/Servlets/Request - История изменений

Admin: 1 версия

в 18:01, 31 мая 2010