// This class is the source code whose specifications appear in the JSON file
// net_connection_spec.json.

package net;

/**
 * Represents a connection on a communication channel. Allows sending messages
 * both coded as integers, or as text strings.
 */
public class Connection {

  /**
   * Creates a closed connection for the given communication channel.
   *
   * @param channel the communication channel, must be non-null
   */
  public Connection(Channel channel) {
   ...
  }

  /**
   * Indicates whether this {@link Connection} is open.
   *
   * @returns true if the connection is open, false otherwise
   */
  public boolean isOpen() {
    ...
  }

  /**
   * Establishes this {@link Connection} allowing messages to be sent
   * and received.
   *
   * @throws IllegalStateException if the connection is already open
   */
  public void open() {
    ...
  }

  /**
   * Sends a text message on this {@link Connection}.
   *
   * @throws NullPointerException if message is null
   * @throws IllegalStateException if the connection is not open
   */
  public void send(String message) {
    ...
  }

  /**
   * Sends a coded integer message on this {@link Connection}
   *
   * @param code  the code, must be positive
   * @throws IllegalStateException if the connection is not open
   */
  public void send(int coded) {
    ...
  }

  /**
   * Receives a coded integer message on this {@link Connection}.
   *
   * @return the received non-negative code value
   * @throws IllegalStateException if the connection is not open
   */
  public int receive() {
    ...
  }
}