title: How to resolve a Stream Closed Error in java?
body: <p>I am really thankful for everyone who would read this and try to help me, the following is the code I am trying to write for a server class for a socket-programming project for college:</p>
  
  <pre><code>import java.io.*;
  import java.net.*;
  import java.io.File;
  
  class Server{
      public static void main (String[]args)throws IOException{
          ServerSocket socket1 = new ServerSocket (8000);
          while (true) {
              Socket incoming = socket1.accept();
              new newclass(incoming).start();
          }
      }
  }
  
  class newclass extends Thread implements Runnable {
  
      Socket incoming;
  
      public newclass(Socket incoming) {
          this.incoming = incoming;
      }
  
      public void run() {
          try {
              byte x = 0;
              String z;
              String s = "HTTP 1.0 200 Document follows";
              String s1 = "Bad request message";
              BufferedReader input = new BufferedReader(new InputStreamReader(incoming.getInputStream()));
              PrintWriter output = new PrintWriter(incoming.getOutputStream(), true);
              DataOutputStream sending = new DataOutputStream(incoming.getOutputStream());
              File directory = new File("C:\\Documents and Settings\\Ahmed\\Desktop\\bla\\Server");
              File[] files = directory.listFiles();
              int x1 = files.length;
              if ((x1 - 3) &lt; 10) {
                  boolean done = false;
                  while (!done) {
                      String line = input.readLine();
                      System.out.println(line);
                      if (line.equals("BYE")) {
                          output.println("BYE");
                          done = true;
                      } else {
                          if (line.trim().substring(0, 3).equals("GET ")) {
                              if (line.equals("&lt;javalogo.png&gt; HTTP    1.0")) {
                                  File f = new File("javalogo.png");
                                  int size = (int) f.length();
                                  if (f.exists() == true) {
                                      output.println(s);
                                      output.println(size);
                                      output.println("javalogo1.png");
                                      DataInputStream bytefile = new DataInputStream(new BufferedInputStream(new FileInputStream(f)));
                                      while (bytefile.available() != 0) {
                                          x = bytefile.readByte();
                                          sending.write(x);
                                      }
                                  } else {
                                      System.out.println("Getting file from main server");
                                      Socket socket2 = new Socket("127.0.0.1", 8100);
                                      BufferedReader bUsr = new BufferedReader(new InputStreamReader(System.in));
                                      PrintWriter pOut = new PrintWriter(socket2.getOutputStream(), true);
                                      BufferedReader bIn = new BufferedReader(new InputStreamReader(socket2.getInputStream()));
                                      pOut.println("GET &lt;javalogo.png&gt; HTTP 1.0");
                                      String rep = bIn.readLine();
                                      if (rep.equals("HTTP 1.0 200 Document follows")) {
                                          int len = Integer.parseInt(bIn.readLine());
                                          String fname = bIn.readLine();
                                          File f1 = new File(fname);
                                          f1.createNewFile();
                                          FileOutputStream fos = new FileOutputStream(f1);
                                          DataInputStream dis = new DataInputStream(socket2.getInputStream());
                                          for (int i = 0; i &lt; len; i++) {
                                              fos.write(dis.read());
                                          }
                                          fos.close();
                                      } else if (rep.equals("File does not exist")) {
                                          output.println("Sorry, but the file was neither found in the proxy server or the main server or the name is wrong.");
                                      }
  
                                  }
                              }
                              File f2 = new File("javalogo.png");
                              if (f2.exists() == true) {
                                  int size = (int) f2.length();
                                  output.println(s);
                                  output.println(size);
                                  output.println("javalogo.png");
                                  DataInputStream bytefile = new DataInputStream(new BufferedInputStream(new FileInputStream(f2)));
                                  while (bytefile.available() != 0) {
                                      x = bytefile.readByte();
                                      sending.write(x);
                                  }
                              }
                          } else {
                              System.out.println(s1);
                              output.println(s1);
                          }
                      }
                  }
                  incoming.close();
  
              }
              output.println("Connecting to main server");
          } catch (Exception ex) {
              System.out.println(ex.getMessage());
          }
      }
  }
  </code></pre>
  
  <p>Now I don't understand why am I getting an error when I run the following client on it.<br>
  I get this really weird error where the buffered reader reads the first line from the user correctly but with the second one it gives me a null exception as if the client wrote null or something, I dont get it.</p>
  
  <p>Here's the client code anyways, if anyone can help me I would be plenty thankful.</p>
  
  <pre><code>import java.net.*;
  import java.io.*;
  
  
  public class Client {
  
      public static void main(String[] args) throws Exception {
  
          Socket socket1 = new Socket("127.0.0.1", 8000);
  
          BufferedReader bUsr = new BufferedReader(new InputStreamReader(System.in));
          PrintWriter pOut = new PrintWriter(socket1.getOutputStream(), true);
          BufferedReader bIn = new BufferedReader(new InputStreamReader(socket1.getInputStream()));
          String cmd;
          String rep;
          while (true) {
              cmd = bUsr.readLine();
              pOut.println(cmd);
  
              System.out.println(rep = bIn.readLine());
  
              if (cmd.equals("BYE") || cmd.equals("END"))
                  break;
              else if (rep.equals("HTTP 1.0 200 Document follows")) {
                  int len = Integer.parseInt(bIn.readLine());
                  String fname = bIn.readLine();
                  File f = new File(fname);
                  f.createNewFile();
                  FileOutputStream fos = new FileOutputStream(f);
                  DataInputStream dis = new DataInputStream(socket1.getInputStream());
                  for (int i = 0; i &lt; len; i++) {
                      fos.write(dis.read());
                  }
  
                  fos.close();
                  System.out.println("Success");
  
              } else if (rep.equals("Connecting to main server")) {
                  Socket socket1 = new Socket("127.0.0.1", 8100);
                  BufferedReader bUsr = new BufferedReader(new InputStreamReader(System.in));
                  PrintWriter pOut = new PrintWriter(socket1.getOutputStream(), true);
                  BufferedReader bIn = new BufferedReader(new InputStreamReader(socket1.getInputStream()));
                  String cmd;
                  String rep;
                  while (true) {
                      cmd = bUsr.readLine();
                      pOut.println(cmd);
  
                      System.out.println(rep = bIn.readLine());
  
                      if (cmd.equals("BYE") || cmd.equals("END"))
                          break;
                      else if (rep.equals("HTTP 1.0 200 Document follows")) {
                          int len = Integer.parseInt(bIn.readLine());
                          String fname = bIn.readLine();
                          File f = new File(fname);
                          f.createNewFile();
                          FileOutputStream fos = new FileOutputStream(f);
                          DataInputStream dis = new DataInputStream(socket1.getInputStream());
                          for (int i = 0; i &lt; len; i++) {
                              fos.write(dis.read());
                          }
  
                          fos.close();
                          System.out.println("Success");
                      }
                  }
              }
  
              bIn.close();
              pOut.close();
              socket1.close();
          }
      }
  </code></pre>
  
  <p>This is the first time asking anything on this site, so if I did anything wrong I would be more than happy to change what I wrote. </p>
  
  <p>By the way, the part in the server which states "getting file from main server" is a part where the server itself becomes a client for a main server, from where it gets the file and sends it to the client, I didn't add the main server code because it'd be too much code but basically it's the same as server without the if condition restricting it to 10 files in the directory only.</p>