Это простое приложение для чата. Сервер и клиент как отдельное приложение. Соединение между сервером и клиентом работает нормально. У меня проблема, когда я пытаюсь отправить String из Client BufferedWriter в Server BufferedReader. У меня есть исключение null-указателя.
И можете ли вы сказать мне, что все в порядке с логикой потоков в этом приложении?Java BufferedWriter при подключении к серверу - исключение null указателя - приложение для чата
приложение Сервер
public class Server {
private int port = 5000;
private ServerSocket server = null;
private Socket socket = null;
private InputStreamReader isr = null;
private OutputStreamWriter osw = null;
private BufferedReader br = null;
private BufferedWriter bw = null;
private Chat chat;
private String message;
private int bOffset = 10;
private JFrame mainFrame;
private JPanel mainPanel;
private JPanel boxPanel;
private JLabel boxTitleLabel;
private JTextArea incomingMessagesJTextArea;
private JTextField messageWritten;
private JButton sendServerButton;
public static void main(String[] args){
System.out.println("Server is running");
new Server().createGUI(); //some swing GUI things
new Server().createServerConnection();
}
public void createServerConnection(){
try {
/** Create socket for communication between apps */
server = new ServerSocket(port);
socket = server.accept();
System.out.println("Server accept client: OK");
/** Create output writers */
osw = new OutputStreamWriter(socket.getOutputStream());
bw = new BufferedWriter(osw);
/** Create inputs readers */
isr = new InputStreamReader(socket.getInputStream()); //data in bytes format
br = new BufferedReader(isr); //data in character format
} catch (IOException e) {
System.out.println("Server Error createServerConnection(): " +e.getMessage());
}
/** Create new thread for read server-input data */
new Thread(new Runnable() {
public void run() {
System.out.println("Server Thread - running");
while (true) {
try {
String message = br.readLine();
System.out.println(message);
} catch (IOException e) {
System.out.println("Server Error createServerConnection() -> new Thread: " +e.getMessage());
}
}
}
}
).start();
}}
приложение Client
public class Client {
private int port = 5000;
private Socket socket = null;
private InputStreamReader isr = null;
private OutputStreamWriter osw = null;
private BufferedReader br = null;
private BufferedWriter bw = null;
private String message;
private int bOffset = 10;
private JFrame mainFrame;
private JPanel mainPanel;
private JPanel boxPanel;
private JLabel boxTitleLabel;
private JTextArea incomingMessagesJTextArea;
private JTextField messageWritten;
private JButton sendServerButton;
public static void main(String[] args){
System.out.println("Client is running");
new Client().createGUI(); //some swing GUI things
new Client().createConnectionWithServer();
new Client().sendTextToServer();
}
public void sendTextToServer(){
try {
message = "test";
bw.write(message); //null pointer exception
bw.write('\n');
bw.flush();
} catch(Exception ex) {
ex.printStackTrace();
}
}
public void createConnectionWithServer(){
try {
/** Create socket for communication between apps */
socket = new Socket("localhost", port);
/** Create inputs readers */
isr = new InputStreamReader(socket.getInputStream()); //data in bytes format
br = new BufferedReader(isr); //data in characters format
/** Create output writers */
osw = new OutputStreamWriter(socket.getOutputStream());
bw = new BufferedWriter(osw);
} catch (IOException e) {
System.out.println("Server Error createConnectionWithServer(): " +e.getMessage());
}
/** Create new thread for read client-input data */
new Thread(new Runnable() {
public void run() {
System.out.println("Client Thread - running");
while (true) {
try {
message = br.readLine();
System.out.println(message);
} catch (IOException e) {
System.out.println("Client Error createServerConnection() -> new Thread: " +e.getMessage());
}
}
}
}
).start();
}}