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电梯直达

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发表于 2003-09-05 09:52 |只看该作者 |倒序浏览

由于客户要求，小弟要用 SERVLET 写一个在远程搜索数据库与读者客户端之间的中间层代理程序。
考虑到有的远程数据库登陆时写了 cookie 进行身份和过期验证，所以，我的这个中间层代理程序需要把这些 cookie 接受到。

现在的问题是：我不知道如何把 cookie 回发给对应的读者客户端。
请帮个忙，多谢！

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knight-yl

家境小康

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发表于 2003-09-05 16:05 |只看该作者

救急：在客户端和服务器之间传递cookie 的问题。

// Changes by: Saar Machtinger, me@cawa.com
import java.net.*;
import java.io.*;
import java.util.*;
class CookiesInJava {
static Hashtable theCookies = new Hashtable();
/**
* Send the Hashtable (theCookies) as cookies, and write them to the specified URLconnection
*
* @param urlConn The connection to write the cookies to.
* @param printCookies Print or not the action taken.
*
* @return The urlConn with the all the cookies in it.
*/
public URLConnection writeCookies(URLConnection urlConn, boolean printCookies){
String cookieString = "";
Enumeration keys = theCookies.keys();
while (keys.hasMoreElements()) {
String key = (String)keys.nextElement();
cookieString += key + "=" + theCookies.get(key);
if (keys.hasMoreElements())
cookieString += "; ";
}
urlConn.setRequestProperty("Cookie", cookieString);
if (printCookies)
System.out.println("Wrote cookies:\n " + cookieString);
return urlConn;
}
/**
* Read cookies from a specified URLConnection, and insert them to the Hashtable
* The hashtable represents the Cookies.
*
* @param urlConn the connection to read from
* @param printCookies Print the cookies or not, for debugging
* @param reset Clean the Hashtable or not
*/
public void readCookies(URLConnection urlConn, boolean printCookies,
boolean reset){
if (reset)
theCookies.clear();
int i=1;
String hdrKey;
String hdrString;
String aCookie;
while ((hdrKey = urlConn.getHeaderFieldKey(i)) != null) {
if (hdrKey.equals("Set-Cookie")) {
hdrString = urlConn.getHeaderField(i);
StringTokenizer st = new StringTokenizer(hdrString,",");
while (st.hasMoreTokens()) {
String s = st.nextToken();
aCookie = s.substring(0, s.indexOf(";"));
// aCookie = hdrString.substring(0, s.indexOf(";"));
int j = aCookie.indexOf("=");
if (j != -1) {
if (!theCookies.containsKey(aCookie.substring(0, j))){
// if the Cookie do not already exist then when keep it,
// you may want to add some logic to update the stored Cookie instead.
// thanks to rwhelan
theCookies.put(aCookie.substring(0, j),aCookie.substring(j + 1));
if (printCookies){
System.out.println("Reading Key: " + aCookie.substring(0, j));
System.out.println(" Val: " + aCookie.substring(j + 1));
}
}
}
}
}
i++;
}
}
/**
* Display all the cookies currently in the HashTable
*
*/
public void viewAllCookies() {
System.out.println("All Cookies are:");
Enumeration keys = theCookies.keys();
String key;
while (keys.hasMoreElements()){
key = (String)keys.nextElement();
System.out.println(" " + key + "=" +
theCookies.get(key));
}
}
/**
* Display the current cookies in the URLConnection, searching for the: "Cookie" header
*
* This is Valid only after a writeCookies operation.
*
* @param urlConn The URL to print the associates cookies in.
*/
public void viewURLCookies(URLConnection urlConn) {
System.out.print("Cookies in this URLConnection are:\n ");
System.out.println(urlConn.getRequestProperty("Cookie"));
}
/**
* Add a specific cookie, by hand, to the HastTable of the Cookies
*
* @param _key The Key/Name of the Cookie
* @param _val The Calue of the Cookie
* @param printCookies Print or not the result
*/
public void addCookie(String _key, String _val, boolean printCookies){
if (!theCookies.containsKey(_key)){
theCookies.put(_key,_val);
if (printCookies){
System.out.println("Adding Cookie: ");
System.out.println(" " + _key + " = " + _val);
}
}
}
}