в 17:43, 31 мая 2010

2010-05-31T17:43:48Z

Admin: 1 версия

2010-05-31T14:35:33Z

1 версия

Новая страница

== HttpServletResponse: addCookie(Cookie arg0) ==



<source lang="java">
import java.io.IOException;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
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 ShoppingCartViewerCookie extends HttpServlet {
public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException,
IOException {
res.setContentType("text/html");
PrintWriter out = res.getWriter();
String sessionid = null;
Cookie[] cookies = req.getCookies();
if (cookies != null) {
for (int i = 0; i < cookies.length; i++) {
if (cookies[i].getName().equals("sessionid")) {
sessionid = cookies[i].getValue();
break;
}
}
}
// If the session ID wasn"t sent, generate one.
// Then be sure to send it to the client with the response.
if (sessionid == null) {
sessionid = generateSessionId();
Cookie c = new Cookie("sessionid", sessionid);
res.addCookie(c);
}
out.println("<HEAD><TITLE>Current Shopping Cart Items</TITLE></HEAD>");
out.println("<BODY>");
// Cart items are associated with the session ID
String[] items = getItemsFromCart(sessionid);
// Print the current cart items.
out.println("You currently have the following items in your cart:<BR>");
if (items == null) {
out.println("<B>None</B>");
} else {
out.println("<UL>");
for (int i = 0; i < items.length; i++) {
out.println("<LI>" + items[i]);
}
out.println("</UL>");
}
// Ask if they want to add more items or check out.
out.println("<FORM ACTION=\"/servlet/ShoppingCart\" METHOD=POST>");
out.println("Would you like to<BR>");
out.println("<INPUT TYPE=SUBMIT VALUE=\" Add More Items \">");
out.println("<INPUT TYPE=SUBMIT VALUE=\" Check Out \">");
out.println("</FORM>");
// Offer a help page.
out.println("For help, click ");
out.println("</BODY></HTML>");
}
private static String generateSessionId() throws UnsupportedEncodingException {
String uid = new java.rmi.server.UID().toString(); // guaranteed unique
return URLEncoder.encode(uid,"UTF-8"); // encode any special chars
}
private static String[] getItemsFromCart(String sessionid) {
return new String[]{"a","b"};
}
}

</source>



== HttpServletResponse: encodeURL(String url) ==



<source lang="java">
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Date;
import java.util.Enumeration;
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 SessionSnoop extends HttpServlet {
public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException,
IOException {
res.setContentType("text/html");
PrintWriter out = res.getWriter();
HttpSession session = req.getSession();
Integer count = (Integer) session.getAttribute("count");
if (count == null)
count = new Integer(1);
else
count = new Integer(count.intValue() + 1);
session.setAttribute("count", count);
out.println("<HTML><HEAD><TITLE>Session Count</TITLE></HEAD>");
out.println("<BODY><H1>Session Count</H1>");
out.println("You"ve visited this page " + count
+ ((count == 1) ? " time." : " times."));
out.println("<P>");
out.println("<H3>Here is your saved session data:</H3>");
Enumeration e = session.getAttributeNames();
while (e.hasMoreElements()) {
String name = (String) e.nextElement();
out.println(name + ": " + session.getAttribute(name) + "<BR>");
}
out.println("<H3>Here are some vital stats on your session:</H3>");
out.println("Session id: " + session.getId() + " <I>(keep it secret)</I><BR>");
out.println("New session: " + session.isNew() + "<BR>");
out.println("Timeout: " + session.getMaxInactiveInterval());
out.println("<I>(" + session.getMaxInactiveInterval() / 60 + " minutes)</I><BR>");
out.println("Creation time: " + session.getCreationTime());
out.println("<I>(" + new Date(session.getCreationTime()) + ")</I><BR>");
out.println("Last access time: " + session.getLastAccessedTime());
out.println("<I>(" + new Date(session.getLastAccessedTime()) + ")</I><BR>");
out.println("Requested session ID from cookie: " + req.isRequestedSessionIdFromCookie()
+ "<BR>");
out.println("Requested session ID from URL: " + req.isRequestedSessionIdFromURL() + "<BR>");
out.println("Requested session ID valid: " + req.isRequestedSessionIdValid() + "<BR>");
out.println("<H3>Test URL Rewriting</H3>");
out.println("Click ");
out.println("to test that session tracking works via URL");
out.println("rewriting even when cookies aren"t supported.");
out.println("</BODY></HTML>");
}
}

</source>



== HttpServletResponse.SC_BAD_REQUEST ==



<source lang="java">
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class GoTo extends HttpServlet {
public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException,
IOException {
// Determine the site where they want to go
String site = req.getPathInfo();
String query = req.getQueryString();
// Handle a bad request
if (site == null) {
res.sendError(res.SC_BAD_REQUEST, "Extra path info required");
}
// Cut off the leading "/" and append the query string
// We"re assuming the path info URL is always absolute
String url = site.substring(1) + (query == null ? "" : "?" + query);
// Log the requested URL and redirect
log(url); // or write to a special file
res.sendRedirect(url);
}
}

</source>



== HttpServletResponse.SC_MOVED_TEMPORARILY ==



<source lang="java">
import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class SiteSelector extends HttpServlet {
Vector<String> sites = new Vector<String>();
Random random = new Random();
public void init() throws ServletException {
sites.addElement("http://www.jexp.ru");
sites.addElement("http://www.servlets.ru");
sites.addElement("http://java.sun.ru/products/servlet");
sites.addElement("http://www.google.ru");
}
public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException,
IOException {
res.setContentType("text/html");
PrintWriter out = res.getWriter();
int siteIndex = Math.abs(random.nextInt()) % sites.size();
String site = sites.elementAt(siteIndex);
res.setStatus(res.SC_MOVED_TEMPORARILY);
res.setHeader("Location", site);
}
}

</source>



== HttpServletResponse: sendError(int arg0, String arg1) ==



<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 Buffering extends HttpServlet {
public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException,
IOException {
res.setBufferSize(8 * 1024); // 8K
res.setContentType("text/html");
PrintWriter out = res.getWriter();
int size = res.getBufferSize(); // returns 8096 or greater
log("The default buffer size is " + size);
out.println("The client won"t see this");
res.reset();
out.println("Nor will the client see this!");
res.reset();
out.println("And this won"t be seen if sendError() is called");
if (req.getParameter("param") == null) {
res.sendError(res.SC_BAD_REQUEST, "param needed");
}
}
}

</source>



== HttpServletResponse: sendRedirect(String arg0) ==



<source lang="java">
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class GoTo extends HttpServlet {
public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException,
IOException {
// Determine the site where they want to go
String site = req.getPathInfo();
String query = req.getQueryString();
// Handle a bad request
if (site == null) {
res.sendError(res.SC_BAD_REQUEST, "Extra path info required");
}
// Cut off the leading "/" and append the query string
// We"re assuming the path info URL is always absolute
String url = site.substring(1) + (query == null ? "" : "?" + query);
// Log the requested URL and redirect
log(url); // or write to a special file
res.sendRedirect(url);
}
}

</source>



== HttpServletResponse: setContentType( text/html; charset=UTF-8 ); ==



<source lang="java">
import java.io.BufferedReader;
import java.io.IOException;
import java.io.OutputStreamWriter;
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 UTF8 extends HttpServlet {
public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException,
IOException {
try {
BufferedReader reader = req.getReader();
res.setContentType("text/html; charset=UTF-8");
PrintWriter out = new PrintWriter(new OutputStreamWriter(res.getOutputStream(), "UTF8"), true);
// Read and write 4K chars at a time
// (Far more efficient than reading and writing a line at a time)
char[] buf = new char[4 * 1024]; // 4Kchar buffer
int len;
while ((len = reader.read(buf, 0, buf.length)) != -1) {
out.write(buf, 0, len);
}
out.flush();
} catch (Exception e) {
getServletContext().log(e, "Problem filtering page to UTF-8");
}
}
}

</source>



== HttpServletResponse: setContentType("text/vnd.wap.wml") ==



<source lang="java">

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Properties;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class AreaCode extends HttpServlet {
private Object[][] data = new Object[][] { { "Yukon Territory", new int[] { 867 } }, };
Properties lookup = new Properties();
public void init() {
for (int i = 0; i < data.length; i++) {
Object[] record = data[i];
String state = (String) record[0];
int[] codes = (int[]) record[1];
for (int j = 0; j < codes.length; j++) {
lookup.put(String.valueOf(codes[j]), state);
}
}
}
public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException,
IOException {
res.setContentType("text/vnd.wap.wml");
PrintWriter out = res.getWriter();
String msg = null;
String code = req.getParameter("code");
String region = null;
if (code != null) {
region = lookup.getProperty(code);
}
out.println("<?xml version=\"1.0\"?>");
out.println("<!DOCTYPE wml PUBLIC " + "\"-//WAPFORUM//DTD WML 1.1//EN\" "
+ "\"http://www.wapforum.org/DTD/wml_1.1.xml\">");
out.println("<wml>");
out.println("<card id=\"Code\" title=\"Code\">");
out.println(" <p>");
out.println(" Area code "" + code + ""<br/>");
if (region != null) {
out.println(" is " + region + ".<br/>");
} else {
out.println(" is not valid.<br/>");
}
out.println(" </p>");
out.println("</card>");
out.println("</wml>");
}

}
/*
<?xml version="1.0"?>
<!DOCTYPE wml PUBLIC
"-//WAPFORUM//DTD WML 1.1//EN"
"http://www.wapforum.org/DTD/wml_1.1.xml">
<wml>
<card id="AreaCode" title="Enter an Area Code">
<do type="accept" label="Enter">
<go href="servlet/AreaCode?code=$(code)"/>
</do>
<p>
Enter an Area Code: <input type="text" name="code"/>
</p>
</card>
</wml>
*/

</source>



== HttpServletResponse: setHeader(String name, String value) ==



<source lang="java">
import java.io.IOException;
import java.io.PrintWriter;
import java.text.DateFormat;
import java.util.Date;
import java.util.Locale;
import java.util.TimeZone;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class HelloSpain extends HttpServlet {
public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException,
IOException {
res.setContentType("text/plain");
PrintWriter out = res.getWriter();
res.setHeader("Content-Language", "es");
Locale locale = new Locale("es", "");
DateFormat fmt = DateFormat.getDateTimeInstance(DateFormat.LONG, DateFormat.LONG, locale);
fmt.setTimeZone(TimeZone.getDefault());
out.println("En Espa\u00f1ol:");
out.println("\u00a1Hola Mundo!");
out.println(fmt.format(new Date()));
}
}

</source>



== HttpServletResponse: setHeader(String name, String value) (2) ==



<source lang="java">
import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class SiteSelector extends HttpServlet {
Vector<String> sites = new Vector<String>();
Random random = new Random();
public void init() throws ServletException {
sites.addElement("http://www.jexp.ru");
sites.addElement("http://www.servlets.ru");
sites.addElement("http://java.sun.ru/products/servlet");
sites.addElement("http://www.google.ru");
}
public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException,
IOException {
res.setContentType("text/html");
PrintWriter out = res.getWriter();
int siteIndex = Math.abs(random.nextInt()) % sites.size();
String site = sites.elementAt(siteIndex);
res.setStatus(res.SC_MOVED_TEMPORARILY);
res.setHeader("Location", site);
}
}

</source>



== HttpServletResponse: setStatus(int status) ==



<source lang="java">
import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class SiteSelector extends HttpServlet {
Vector<String> sites = new Vector<String>();
Random random = new Random();
public void init() throws ServletException {
sites.addElement("http://www.jexp.ru");
sites.addElement("http://www.servlets.ru");
sites.addElement("http://java.sun.ru/products/servlet");
sites.addElement("http://www.google.ru");
}
public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException,
IOException {
res.setContentType("text/html");
PrintWriter out = res.getWriter();
int siteIndex = Math.abs(random.nextInt()) % sites.size();
String site = sites.elementAt(siteIndex);
res.setStatus(res.SC_MOVED_TEMPORARILY);
res.setHeader("Location", site);
}
}

</source>



== ServletResponse: setBufferSize(int arg0) ==



<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 Buffering extends HttpServlet {
public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException,
IOException {
res.setBufferSize(8 * 1024); // 8K
res.setContentType("text/html");
PrintWriter out = res.getWriter();
int size = res.getBufferSize(); // returns 8096 or greater
log("The default buffer size is " + size);
out.println("The client won"t see this");
res.reset();
out.println("Nor will the client see this!");
res.reset();
out.println("And this won"t be seen if sendError() is called");
if (req.getParameter("param") == null) {
res.sendError(res.SC_BAD_REQUEST, "param needed");
}
}
}

</source>

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в 17:43, 31 мая 2010

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