I'm trying to develop a client-server exchange program, and when I try to send data from client to server, I'm running into a SocketException. I've looked at other answers but none of them fit my exact case; I have two calls to osw.write, and only one of them works.
Client:
package me.primesearch.client; import java.math.BigInteger; import java.net.*; import java.io.*; public class PrimeSearchClient { public static void main(String[] args) throws IOException{ Socket connection = null; try{ /** Define a host server */ String host = "localhost"; /** Define a port */ int port = 25564; StringBuffer instr = new StringBuffer(); System.out.println("SocketClient initialized"); /** Obtain an address object of the server */ InetAddress address = InetAddress.getByName(host); /** Establish a socket connetion */ connection = new Socket(address, port); /** Instantiate a BufferedOutputStream object */ BufferedOutputStream bos = new BufferedOutputStream(connection. getOutputStream()); /** Instantiate a BufferedInputStream object for reading /** Instantiate a BufferedInputStream object for reading * incoming socket streams. */ BufferedInputStream bis = new BufferedInputStream(connection. getInputStream()); /**Instantiate an InputStreamReader with the optional * character encoding. */ InputStreamReader isr = new InputStreamReader(bis, "US-ASCII"); /**Read the socket's InputStream and append to a StringBuffer */ int c; /** Instantiate an OutputStreamWriter object with the optional character * encoding. */ OutputStreamWriter osw = new OutputStreamWriter(bos, "US-ASCII"); while(true){ String process = "drq " + (char) 13; /** Write across the socket connection and flush the buffer */ osw.write(process); osw.flush(); while ( (c = isr.read()) != 13) instr.append( (char) c); for(int i=0;i<50;i++){ BigInteger offset=new BigInteger(instr.toString()).add(BigInteger.valueOf(i)); if(isProbablyPrime(offset)){ process = "pri" + " " + offset + " " + (offset.divide(new BigInteger("50"))).toString() + (char) 13; System.out.println(process); /** Write across the socket connection and flush the buffer */ osw.write(process); //This doesn't work osw.flush(); System.out.println("Prime found at " + offset); } } } } catch(IOException e) { e.printStackTrace(); } finally { connection.close(); } } public static boolean isProbablyPrime(BigInteger n) { if(n.longValue()!=0){ BigInteger lessOne = n.subtract(BigInteger.ONE); // get the next prime from one less than number and check with the number return lessOne.nextProbablePrime().compareTo(n) == 0; } return false; } } Server:
package me.primesearch.server; import java.net.*; import java.io.*; public class PrimeSearchServer implements Runnable { private Socket connection; @SuppressWarnings("unused") private int ID; PrimeSearchServer(Socket s, int i) { this.connection = s; this.ID = i; } @SuppressWarnings("resource") public static void main(String[] args) { int port = 25564; int count = 0; try{ ServerSocket socket1 = new ServerSocket(port); System.out.println("MultipleSocketServer Initialized"); while (true) { Socket connection = socket1.accept(); Runnable runnable = new PrimeSearchServer(connection, ++count); Thread thread = new Thread(runnable); thread.start(); } } catch (Exception e) { e.printStackTrace(); } } @Override public void run() { try { BufferedInputStream is = new BufferedInputStream(connection.getInputStream()); InputStreamReader isr = new InputStreamReader(is); int character; StringBuffer process = new StringBuffer(); while((character = isr.read()) != 13) { process.append((char)character); } System.out.println(process); String returnCode="0"; if(process.toString().split(" ")[0].equals("drq")){ System.out.println("Job request recieved"); File file = new File("packages.txt"); //Process input try (BufferedReader br = new BufferedReader(new FileReader(file))) { String line; String prevLine=""; boolean i = false; int count=0; while ((line = br.readLine()) != null) { System.out.println("Looking for a package to send"); // process the line. if(line.equals("0")){ System.out.println("Sending package " + count); returnCode = Integer.toString(count); i = true; break; } prevLine = line; count++; System.out.println("No packages found"); } if(!i){ returnCode = prevLine; try(PrintWriter out = new PrintWriter(new BufferedWriter(new FileWriter("packages.txt", true)))) { System.out.println("Creating new package"); out.println("0"); returnCode=Integer.toString(count); }catch (IOException e) { e.printStackTrace(); } } } } else if (process.toString().split(" ")[0].equals("pri")){ System.out.println("Prime request recieved"); try(PrintWriter out = new PrintWriter(new BufferedWriter(new FileWriter("primes.txt", true)))) { out.println(Integer.parseInt(process.toString().split(" ")[1])); }catch (IOException e) { e.printStackTrace(); } updateLine(Integer.parseInt(process.toString().split(" ")[2])); } BufferedOutputStream os = new BufferedOutputStream(connection.getOutputStream()); OutputStreamWriter osw = new OutputStreamWriter(os, "US-ASCII"); osw.write(returnCode + (char)13); osw.flush(); process = new StringBuffer(); } catch (Exception e) { System.out.println(e); } finally { try { connection.close(); } catch (IOException e){ e.printStackTrace(); } } } private void updateLine(int lines) throws IOException { String data="packages.txt"; BufferedReader file = new BufferedReader(new FileReader(data)); String input = ""; String line; for(int i=0;i<lines;i++){ input+=file.readLine()+System.lineSeparator(); } file.readLine(); while ((line = file.readLine()) != null) input += line + System.lineSeparator(); FileOutputStream os = new FileOutputStream(data); os.write(input.getBytes()); file.close(); os.close(); } } Sorry if the indenting on the code looks a bit strange, I'm not used to using stack overflow.
