3
看看這些代碼：何時使用Java在HttpURLConnection中設置cookie？
public static String get(String url, Properties parameters) throws MalformedURLException, IOException{
url = buldGetUrl(url, parameters);
if(DEBUG) System.out.println("[HTTP GET REQUEST]");
if(DEBUG) System.out.println(" URL: " + url);
HttpURLConnection conn = (HttpURLConnection) new URL(url).openConnection();
conn.setRequestProperty("Cookie","JSESSIONID=" + J_SESSION_ID);
conn.connect();
if(DEBUG) System.out.println("\n[HTTP GET RESPONSE]");
if(DEBUG) System.out.println("==== Response Headers =====");
String serverCookies = conn.getHeaderField("Set-Cookie");
if(serverCookies != null){
String[] cookies = serverCookies.split(";");
for(String s : cookies){
s = s.trim();
if(s.split("=")[0].equals("JSESSIONID")){
J_SESSION_ID = s.split("=")[1];
if(DEBUG) System.out.println(" Session ID Found: " + J_SESSION_ID);
break;
}
}
}
if(DEBUG){
for(String s : conn.getHeaderFields().keySet()){
if(s == null)
System.out.println(" " + conn.getHeaderField(s));
else
System.out.println(" " + s + "=" + conn.getHeaderField(s));
}
}
if(DEBUG) System.out.println("==== Response Content =====");
BufferedReader br = new BufferedReader(new InputStreamReader(conn.getInputStream()));
String str = null;
StringBuilder sb = new StringBuilder();
while ((str = br.readLine()) != null) {
sb.append(str + System.getProperty("line.separator"));
if(DEBUG) System.out.println(str);
}
br.close();
return sb.toString();
}
請注意以下三行：
HttpURLConnection conn = (HttpURLConnection) new URL(url).openConnection();
conn.setRequestProperty("Cookie","JSESSIONID=" + J_SESSION_ID);
conn.connect();
URL＃的openConnection和URL＃連接，該方法將請求發送到服務器？ 如果答案是openConnection方法，請求已被髮送後如何設置cookie？如果答案是連接方法，你猜是什麼？下面這些代碼工作過，我可以從服務器響應：
url = buldGetUrl(url, parameters);
if(DEBUG) System.out.println("[HTTP GET REQUEST]");
if(DEBUG) System.out.println(" URL: " + url);
HttpURLConnection conn = (HttpURLConnection) new URL(url).openConnection();
if(DEBUG) System.out.println("\n[HTTP GET RESPONSE]");
if(DEBUG) System.out.println("==== Response Headers =====");
String serverCookies = conn.getHeaderField("Set-Cookie");
if(serverCookies != null){
String[] cookies = serverCookies.split(";");
for(String s : cookies){
s = s.trim();
if(s.split("=")[0].equals("JSESSIONID")){
J_SESSION_ID = s.split("=")[1];
if(DEBUG) System.out.println(" Session ID Found: " + J_SESSION_ID);
break;
}
}
}
if(DEBUG){
for(String s : conn.getHeaderFields().keySet()){
if(s == null)
System.out.println(" " + conn.getHeaderField(s));
else
System.out.println(" " + s + "=" + conn.getHeaderField(s));
}
}
if(DEBUG) System.out.println("==== Response Content =====");
BufferedReader br = new BufferedReader(new InputStreamReader(conn.getInputStream()));
String str = null;
StringBuilder sb = new StringBuilder();
while ((str = br.readLine()) != null) {
sb.append(str + System.getProperty("line.separator"));
if(DEBUG) System.out.println(str);
}
br.close();
return sb.toString();
但你怎麼解釋這一點。在我的第二個例子中，我根本沒有調用open（）方法，但我也可以從服務器獲得響應。 – CaiNiaoCoder
@CaiNiaoCoder看看這個答案http://stackoverflow.com/questions/2151359/java-httpurlconnection-doesnt-connect-when-i-call-connect。感謝您的問題 – vinoth