1. User Agent -> Server

POST /acme/login HTTP/1.1

[form data]

2. Server -> User Agent

HTTP/1.1 200 OK

Set-Cookie2: Customer="WILE_E_COYOTE"; Version="1"; Path="/acme"

3. User Agent -> Server

POST /acme/pickitem HTTP/1.1

Cookie: $Version="1"; Customer="WILE_E_COYOTE"; $Path="/acme"

[form data]

URL url = new URL( "http://java.sun.com/" );

URLConnection conn = url.openConnection();

conn.setRequestProperty("Cookie", "foo=bar");

InputStream is = conn.getInputStream();

......

URL url = new URL( "http://java.sun.com/" );

URLConnection conn = url.openConnection();

conn.connect();

.....

Map<String, List<String>> headers = conn.getHeaderFields();

List<String> values = headers.get("Set-Cookie"); 

String cookieValue = null;

for (Iterator iter = values.iterator(); iter.hasNext(); ) {

String v = values.next();

if (cookieValue == null)

cookieValue = v;

else

cookieValue = cookieValue + ";" + v;

} 

public abstract Map<String,List<String>> get(URI uri,Map<String,List<String>> requestHeaders)

throws IOException

Gets all the applicable cookies from a cookie cache for the specified uri in the request header. HTTP protocol implementers should make sure that this method is called after all request headers related to choosing cookies are added, and before the request is sent.

该方法用于从Cookie Cache(也就是CookieStore)中获取所有的可以使用的Cookie。

HTTP协议的实现应该确保这个方法在相关Cookie 请求头被设置后，在请求发送之前被调用。