Getting Received "" (no content receive) error for 2nd ping in respond to mulitple pings stage redis, java

General
1

I have passed this stage earlier, but then after refactoring my code, I am getting this error
remote: [tester::#ZU2] client-2: $ redis-cli PING
remote: [tester::#ZU2] client-2: Sent bytes: “*1\r\n$4\r\nPING\r\n”
remote: [tester::#ZU2] Received: “” (no content received)
remote: [tester::#ZU2] ^ error
remote: [tester::#ZU2] Error: Expected start of a new RESP2 value (either +, -, :, $ or *)

My code is this:
public static void main(String args){
// You can use print statements as follows for debugging, they’ll be visible when running tests.
System.out.println(“Logs from your program will appear here!”);

 // Uncomment this block to pass the first stage
    ServerSocket serverSocket = null;
    Socket clientSocket = null;
    int port = 6379;
    try {
        serverSocket = new ServerSocket(port);
        // Since the tester restarts your program quite often, setting SO_REUSEADDR
        // ensures that we don't run into 'Address already in use' errors
        serverSocket.setReuseAddress(true);
        // Wait for connection from client.
        clientSocket = serverSocket.accept();

// clientSocket.getOutputStream().write(“+PONG\r\n”.getBytes());
// System.out.println(“Received PONG from client!”);
System.out.printf(“Connected with Client : " + clientSocket.getPort() +”\n");
readMultiplePingsFromSameConnection(clientSocket);
}
catch (IOException e) {
System.out.println("IOException: " + e.getMessage());
} finally {
try {
if (clientSocket != null) {
clientSocket.close();
}
} catch (IOException e) {
System.out.println("IOException: " + e.getMessage());
}
}
}

private static void readMultiplePingsFromSameConnection(Socket clientSocket)  throws IOException{
    BufferedReader br = new BufferedReader(
            new InputStreamReader(clientSocket.getInputStream()));
    OutputStream outputStream = clientSocket.getOutputStream();
    String line;
    while ((line = br.readLine()) != null) {
        System.out.printf("send response of ping : " + line + "\n");
        if (line.equalsIgnoreCase("PING")) {
            outputStream.write("+PONG\r\n".getBytes());
            System.out.println("Received PONG from client!");
        }
    }
}

I have refactored it by referring to one of the code examples but still getting this error.
I tried with code example directly, still getting same error, can someone help me with this?