error message : stream closed

Question

Upon running following code under class FlightSearch

String moreSearch = "y";
    List<Flight> resultList;

    // load initial flight data into DB
    if (!init()) {
        return;
    }
    // A background thread to monitor changes in csv repository
    FileListner fl = new FileListner();
    fl.start();

    do {
        InputStreamReader isr = new InputStreamReader(System.in);
        BufferedReader br = new BufferedReader(isr);
        // main thread gets input
        Input inputQuery = new Input();
        try {
            inputQuery.getQuery();
        } catch (InvalidException e1) {
            e1.getMessage();
        } finally {
            fl.stopThread();
        }
        // main thread STARTs processing task as background monitors csv
        // repo
        QueryProcessor processor = new QueryProcessor();
        resultList = null;
        resultList = processor.matchQuery(inputQuery);

        displayResult(resultList, inputQuery.getFlightClass());

        System.out
                .println("More Flight Query ? Press n/N to exit. Anyother key to continue searching.");

        try {
            moreSearch = br.readLine(); // LINE 56
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally{
            if(br!=null){
                try {
                    br.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }


    } while (!moreSearch.equalsIgnoreCase("n"));

    System.out.println("Thank You !!!");

I get following error :

java.io.IOException: Stream closed
at java.io.BufferedInputStream.getBufIfOpen(BufferedInputStream.java:162)
at java.io.BufferedInputStream.read(BufferedInputStream.java:325)
at sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:283)
at sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:325)
at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:177)
at java.io.InputStreamReader.read(InputStreamReader.java:184)
at java.io.BufferedReader.fill(BufferedReader.java:154)
at java.io.BufferedReader.readLine(BufferedReader.java:317)
at java.io.BufferedReader.readLine(BufferedReader.java:382)
at com.myApp.FlightSearch.main(FlightSearch.java:56)

I have also tried moving

InputStreamReader isr = new InputStreamReader(System.in);
BufferedReader br = new BufferedReader(isr);

moving out of do-while loop but in vain.

Answer 1

Your issue is that you're calling br.close() in the finally block where you read a line from the buffer. When you close a Stream, any stream that was wrapped by the one you closed is also closed. As a result, your first iteration through the do { } while () loop is closing the System.in InputStream, which you cannot then reopen.

To avoid this, you can use a CloseShieldInputStream from Apache Commons to wrap System.in before you wrap it with the InputStreamReader. This will allow you to close the BufferedReader (which will also close the InputStreamReader and the CloseShieldInputStream) without triggering the closure of System.in.

See bmargulies answer here: Closing BufferedReader and System.in

Answer 2

After making changes as suggested in previous answer my code didn't tun but with slight more changes as shown below, my code compiled and run just fine

    try {
        do {
            // main thread gets input
            Input inputQuery = new Input();
            inputQuery.getQuery();

            // main thread STARTs processing task as background monitors csv
            // repo
            QueryProcessor processor = new QueryProcessor();
            resultList = null;
            resultList = processor.matchQuery(inputQuery);

            displayResult(resultList, inputQuery.getFlightClass());
            System.out
                    .println("More Flight Query ? Press n/N to exit. Anyother key to continue searching.");
            moreSearch = br.readLine();

        } while (!moreSearch.equalsIgnoreCase("n"));
    } catch (IOException e) {
        e.printStackTrace();
    } catch (InvalidException e1) {
        e1.getMessage();
    } finally {
        fl.stopThread();
        if (br != null) {
            try {
                br.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
    System.out.println("Thank You !!!");
}

thanks for help.

Answer 3

The problem

The problem is that you execute the br.close() that, as javadoc states, closes the stream and releases any system resources associated with it.

Just for a quick verification comment out the:

if (br != null) {
//    try {
//        br.close();
//    } catch (IOException e) {
//        // TODO Auto-generated catch block
//        e.printStackTrace();
//    }
}

and you can answer s any times you want without any exception.

A solution

A solution is closing the buffer reader after all reads are terminated:

    String moreSearch = null;
    InputStreamReader isr = new InputStreamReader(System.in);
    BufferedReader br = new BufferedReader(isr);
    try {
        do {
            // ...
            System.out.println("More Flight Query ? Press n/N to exit. Anyother key to continue searching.");
            moreSearch = br.readLine();
        } while (!moreSearch.equalsIgnoreCase("n"));

    } catch (IOException e) {
        Logger.getLogger(FlightSearch.class.getName()).log(Level.SEVERE, "Cant read line from a System.in based BufferedReader", e);
    } finally {
        if (br != null) {
            try {
                br.close();
            } catch (IOException ignoreMe) {
                Logger.getLogger(FlightSearch.class.getName()).log(Level.SEVERE, "Can't close a System.in based BufferedReader", ignoreMe);
            }
        }
    }