ClientHandler.java

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.Socket;

class ClientHandler implements Runnable {
  
  private final Socket s;
  
  public ClientHandler(Socket s) {
    this.s = s;
  }

  @Override
  public void run() {
    try {
      try (DataInputStream in = new DataInputStream(s.getInputStream());
           DataOutputStream out = new DataOutputStream(s.getOutputStream())) {
        int stringCount = in.readInt();
        for (int i = 0; i < stringCount; i++) {
          out.writeUTF(in.readUTF());
        }
      }
    } finally {
      try {
        s.close();
      } catch (IOException e) {
        e.printStackTrace();
      }
      return;
    }
  }
}