java-design-patterns/null-object/src/main/java/com/iluwatar/nullobject/NodeImpl.java

package com.iluwatar.nullobject;

/**
 * 
 * Implementation for binary tree's normal nodes.
 *
 */
public class NodeImpl implements Node {

  private final String name;
  private final Node left;
  private final Node right;

  public NodeImpl(String name, Node left, Node right) {
    this.name = name;
    this.left = left;
    this.right = right;
  }

  @Override
  public int getTreeSize() {
    return 1 + left.getTreeSize() + right.getTreeSize();
  }

  @Override
  public Node getLeft() {
    return left;
  }

  @Override
  public Node getRight() {
    return right;
  }

  @Override
  public String getName() {
    return name;
  }

  @Override
  public void walk() {
    System.out.println(name);
    if (left.getTreeSize() > 0) {
      left.walk();
    }
    if (right.getTreeSize() > 0) {
      right.walk();
    }
  }
}