Admin: 1 версия

2010-06-01T06:11:47Z

1 версия

в 18:01, 31 мая 2010

2010-05-31T18:01:43Z

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== Add headers to prevent browsers and proxies from caching this reply. ==



<source lang="java">

import javax.servlet.http.HttpServletResponse;
/*
* 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]
*/
public class Main {
/**
* Add headers to prevent browsers and proxies from caching this reply.
* @param resp The response to add headers to
*/
public static void addNoCacheHeaders(HttpServletResponse resp)
{
// Set standard HTTP/1.1 no-cache headers.
resp.setHeader("Cache-Control", "no-store, no-cache, must-revalidate");
// Set IE extended HTTP/1.1 no-cache headers (use addHeader).
resp.addHeader("Cache-Control", "post-check=0, pre-check=0");
// Set standard HTTP/1.0 no-cache header.
resp.setHeader("Pragma", "no-cache");
// Set to expire far in the past. Prevents caching at the proxy server
resp.setHeader("Expires", "Sat, 6 May 1995 12:00:00 GMT");
}
}

</source>



== Get output stream from HttpServletResponse ==



<source lang="java">

import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
public class CounterServer extends HttpServlet {
static final String COUNTER_KEY = "Counter.txt";
public void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException,
IOException {
HttpSession session = req.getSession(true);
int count = 1;
Integer i = (Integer) session.getAttribute(COUNTER_KEY);
if (i != null) {
count = i.intValue() + 5;
}
session.setAttribute(COUNTER_KEY, new Integer(count));
DataInputStream in = new DataInputStream(req.getInputStream());
resp.setContentType("application/octet-stream");
ByteArrayOutputStream byteOut = new ByteArrayOutputStream();
DataOutputStream out = new DataOutputStream(byteOut);
out.writeInt(count);
out.flush();
byte[] buf = byteOut.toByteArray();
resp.setContentLength(buf.length);
ServletOutputStream servletOut = resp.getOutputStream();
servletOut.write(buf);
servletOut.close();
}
}

</source>



== Set content type to charset=ISO-8850-1 ==



<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;
public class UnknownEncodingServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException,
ServletException {
response.setContentType("text/html; charset=ISO-8850-1");
PrintWriter out = response.getWriter();
}
}

</source>



== URL rewriting through HttpServletResponse ==



<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 CounterRewrite 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");
String url = req.getRequestURI();
out.println("<form method=GET action=\"" + resp.encodeURL(url) + "\">");
out.println("<input type=submit " + "value=\"Hit page again\">");
out.println("</form>");
out.println("</body>");
out.println("</html>");
out.flush();
}
}

</source>

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Admin: 1 версия

в 18:01, 31 мая 2010