x.Hm have a client server java program where the server accepts query requests f

Question

x.Hm have a client server java program where the server accepts query requests from clients and sometimes returns the result. I keep getitng outofmemory error. I search online and found you can increase the runtime java heapspace with Xmx128m... Also, something might now be getting deleted properly. I have closed all connections and most other things that I possibly could.

The only things I don't close are
                  //isr.close(); is.close();
                  //os.close(); osw.close();
but when I try and close them, not all the input goes through and I get a wierd error in the client program.


I would appreciate any ideas-suggestions

Thanks
Ryan




Exception in thread "Thread-4" java.lang.OutOfMemoryError: Java heap space
   at java.util.Arrays.copyOf(Arrays.java:2894)
   at java.lang.AbstractStringBuilder.expandCapacity(AbstractStringBuilder.java:117)
   at java.lang.AbstractStringBuilder.append(AbstractStringBuilder.java:589)
   at java.lang.StringBuffer.append(StringBuffer.java:337)
   at stockserver.MultipleSocketServer.run(MultipleSocketServer.java:57)
   at java.lang.Thread.run(Thread.java:636)





public void run() {
    StringBuffer process = null;
    String returnCode;
    returnCode = "" + ((char) 13);
    try{
          int character;
          while (true) {
              BufferedInputStream is = new BufferedInputStream(conn.getInputStream());
              InputStreamReader isr = new InputStreamReader(is);
                
              process = new StringBuffer();
              while((character = isr.read()) != 13) {
                process.append((char)character);
              }//
               
                  //Remove terminating symbol
                  int y = process.indexOf(Character.toString((char)13));
                  String x = process.substring(0, process.length()-1);
                
                  //Find out what the process should
                  String type = x.substring(0, 2);
                  String sqlstmt = x.substring(2, x.length());
                  System.out.println("sqlstmt is " + sqlstmt + "    type is " + type);
                  if(type.compareTo("01") == 0){
                      System.out.println("Inside 01 " + sqlstmt);
                      InsertNewStock(sqlstmt);
                  }
                  else if(type.compareTo("02") == 0){
                    
                  }
                  else if (type.compareTo("03") == 0)
                  {System.out.println("Inside 03");
                     returnCode = ReturnQuery(sqlstmt);
                  }
                
                
                  System.out.println("process " + process.toString());
                         //need to wait 10 seconds for the app to update database
               try {
                Thread.sleep(10000);
              }
              catch (Exception e){}
              BufferedOutputStream os = new BufferedOutputStream(conn.getOutputStream());
              OutputStreamWriter osw = new OutputStreamWriter(os, "US-ASCII");
                  System.out.println("Writing return statement " + returnCode);
                  returnCode = returnCode + (char) 13;
              osw.write(returnCode);
              osw.flush();
                  //isr.close(); is.close();
                  //os.close(); osw.close();
           }
          }
          catch (IOException e) {}
            try {
    &nb

Explanation / Answer

The OutOfMemoryError is always caused by infinite loop. The following loop only works if the program is running inWindows. The new line character in Linux or Unix is 0x0a ( 10 indecimal), so you cannot detect the end of line if you only checkwhether the character is 0x0d (13 in decimal).              while((character = isr.read()) != 13) {
              process.append((char)character);
            }// If that is not the case, you can try to use System.gc() tosuggest Java VM to start garbage collection, which could alleviatethe high memory usage to some extent.

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