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At first I thought this is a programming issue as I am creating connections every 10 seconds.Which might get into creating connections and not properly closing it.But as suggested its not programming but an implementation/design issue.

I need to check for any new resource available every 5 or 10 seconds ex: testign.com/list_items. The webservices are developed using cakephp.

If any resource available I will be processing it. Can anyone help/guide me to connect to url and poll the new resource every 10 secs.

Every 10 secs doing the below code gives a connection refused or connection timed out exception after 20 loops and also after the exception starts hitting in, the url cannot be loaded on the browser.

oracleIncoming = new URL("http://calvins.restasy.com/bills/list_current/Kitchen");
    inputStreamReaderList = new InputStreamReader(oracleIncoming.openStream());

    //= new InputStreamReader(oracle.openStream());
    for (int j = 0; j < 10;) {
        URLReader.inputStreamReaderList.close();
        inputStreamReaderList = new InputStreamReader(oracleIncoming.openStream());




        BufferedReader in = new BufferedReader(URLReader.inputStreamReaderList);

    String inputLine;
    while ((inputLine = in.readLine()) != null) {
        URLReader.storeInput = URLReader.storeInput + inputLine;
    }
    in.close();

        URLReader.storeInput = "";
        //send response with bill no
        if (URLReader.sendBillNo == true) {
            URLReader.sendBillNo = false;

            oracle = new URL("http://calvins.restasy.com/bills/successfully_generated/" +billNo+"/"+"Kitchen");
            inputStreamReader = new InputStreamReader(oracle.openStream());
             try {

                BufferedReader in2 = new BufferedReader(inputStreamReader);


                String inputLine2;
                while ((inputLine2 = in2.readLine()) != null) {
                    urlBillData2 = urlBillData2 + inputLine2;
                }
                in.close();
                inputStreamReader.close();
            } catch (Exception e) {
                System.out.println(e);
            }
            System.out.println("Successfully Printed Order " + billNo);
            //System.out.println("http://calvins.restasy.com/bills/successfully_generated/" +billNo);
        }
        Thread.sleep(10000);
    }
} catch (Exception e) {
    System.out.println(e);
    callWeb();
}

Here is the stack trace:

java.net.ConnectException: Connection timed out: connect
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:351)
at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:213)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:200)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)
at java.net.Socket.connect(Socket.java:529)
at java.net.Socket.connect(Socket.java:478)
at sun.net.NetworkClient.doConnect(NetworkClient.java:163)
at sun.net.www.http.HttpClient.openServer(HttpClient.java:394)
at sun.net.www.http.HttpClient.openServer(HttpClient.java:529)
at sun.net.www.http.HttpClient.<init>(HttpClient.java:233)
at sun.net.www.http.HttpClient.New(HttpClient.java:306)
at sun.net.www.http.HttpClient.New(HttpClient.java:323)
at sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(HttpURLConnection.java:970)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:911)
at sun.net.www.protocol.http.HttpURLConnection.connect(HttpURLConnection.java:836)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1172)
at java.net.URL.openStream(URL.java:1010)
at printerapp.URLReader.callWeb(URLReader.java:122)
at printerapp.URLReader.main(URLReader.java:71)

As HotLicks suggested to respond from web-service only after any resource is available, the php timeout for an execution is 30 seconds. How to keep a request alive for more than this time.Increasing PHP execution time limit would be a security issue.

Thanks in advance.

4

2 回答 2

0 
while(true) {
    dataIncoming = new URL("http://xyz.com/bills/list_current/Kitchen");
    inputStreamReaderList = new InputStreamReader(dataIncoming.openStream());

    //Your code

    try {
        Thread.sleep(5000);
    } catch(Exception e) {
        //Thread.sleep() can throw an exception if you
        //notify the thread from another thread
    }
}
于 2013-05-01T16:32:01.630 回答
0

In general, you should not be polling a web site every 5 seconds. Where near instantaneous response is needed the web site should provide a mechanism where you can issue a get and the server will not respond until there is data available (though there should generally be a timeout after several minutes).

于 2016-08-18T12:15:13.983 回答