co zostało zrobione, gdy URL.openconnection ()?
Chcę wiedzieć, co zostało zrobione, gdy URL.openconnection ().
zrobiłem taki test:
public static void main(String[] args) {
// testConnection("http://www.google.com");
testConnection("http://219.09.34.23.1");
}
private static void testConnection(final String _url) {
new Thread(new Runnable() {
String strurl = _url;
long starttime = 0;
long endtime = 0;
public void run() {
try {
System.out.println("open:" + strurl);
starttime = System.currentTimeMillis();
System.out.println("starttime:" + starttime);
URL url = new URL(strurl);
HttpURLConnection conn = (HttpURLConnection) url
.openConnection();
endtime = System.currentTimeMillis();
System.out.println("openConnection endtime:" + endtime);
System.out
.println("spend:" + (endtime - starttime) + " ms");
conn.connect();
endtime = System.currentTimeMillis();
System.out.println("connect endtime2:" + endtime);
System.out
.println("spend:" + (endtime - starttime) + " ms");
conn.getResponseCode();
endtime = System.currentTimeMillis();
System.out.println("endtime3:" + endtime);
System.out
.println("spend:" + (endtime - starttime) + " ms");
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
endtime = System.currentTimeMillis();
System.out.println("MalformedURLException endtime:"
+ endtime);
System.out
.println("spend:" + (endtime - starttime) + " ms");
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
endtime = System.currentTimeMillis();
System.out.println(" IOException endtime:" + endtime);
System.out
.println("spend:" + (endtime - starttime) + " ms");
}
}
}).start();
}
kiedy uruchamiam testConnection („http://www.google.com”), wszystko jest w porządku.
kiedy uruchomię testConnection („http: //219.09.34.23.1”), „219.09.34.23.1” jest przypadkowym ip, który może nie istnieje, napisałem to, drukuje to:
open:http://219.09.34.23.1
starttime:1338978920350
openconnection endtime:1338978920355
spend:5 ms
java.net.UnknownHostException: 219.09.34.23.1
at java.net.PlainSocketImpl.connect(Unknown Source)
at java.net.SocksSocketImpl.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at sun.net.NetworkClient.doConnect(Unknown Source)
at sun.net.www.http.HttpClient.openServer(Unknown Source)
at sun.net.www.http.HttpClient.openServer(Unknown Source)
at sun.net.www.http.HttpClient.<init>(Unknown Source)
at sun.net.www.http.HttpClient.New(Unknown Source)
at sun.net.www.http.HttpClient.New(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.connect(Unknown Source)
at Main$1.run(Main.java:37)
at java.lang.Thread.run(Unknown Source)
IOException endtime:1338978920393
spend:43 ms
oznacza to, że spędził 5 ms na uruchomieniu openconnection i spędził 43ms na znalezieniu nieznanego hosta, moim problemem jest to, co zostało zrobione, gdy URL.openconnection () jako „219.09.34.23.1” jest nieznanym hostem? Dzięki za pomoc!