Java socket not printing what it should

Question

Server:

BufferedReader inFromClient = new BufferedReader(new InputStreamReader(connectionSocket.getInputStream()));
            String s = inFromClient.readLine();
            System.out.println("> "+s);

This simple code is returning the following output:

How to make it not show these squares in the output, but show the content the message (fifth line of the console)?

Complete code:

package com.estilosoft.servidor;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader; 
import java.net.ServerSocket;
import java.net.Socket;

public class Servidor {

public static void main(String[] args) throws IOException {
    // TODO Auto-generated method stub

    String clientSentence;
    String capitalized;
    ServerSocket socket = null;

    try {

        // Cria um SocketServer (Socket característico de um servidor)
        socket = new ServerSocket(6831);
        System.out.println("abriu");

        while(true) {    
            Socket connectionSocket = socket.accept();
            System.out.println("Con "+ connectionSocket.getInetAddress().getHostAddress());

            BufferedReader inFromClient = new BufferedReader(new InputStreamReader(connectionSocket.getInputStream()));
            System.out.println("Iniciou");
            String s = inFromClient.readLine();
            System.out.println("Acabou");
            System.out.println("> "+s);


        } 

    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
        socket.close();
        System.out.println("fechou");
    }  
}


}