{"id":80880,"date":"2019-11-20T11:00:57","date_gmt":"2019-11-20T09:00:57","guid":{"rendered":"http:\/\/examples.javacodegeeks.com\/?p=80880"},"modified":"2021-09-20T12:48:18","modified_gmt":"2021-09-20T09:48:18","slug":"java-node-example","status":"publish","type":"post","link":"https:\/\/examples.javacodegeeks.com\/java-node-example\/","title":{"rendered":"Java Node Example"},"content":{"rendered":"

In this article, we will discuss a simple Java Node class through examples.<\/p>\n

1. What is a Node<\/h2>\n

An Individual Node in java is a class that is used to create the individual data holding blocks for various data structures, which organize data in a nonsequential fashion.<\/p>\n

\n
\"Java<\/a><\/figure>\n<\/div>\n

2. Implementations of Node class<\/h2>\n

A Node class can be customized to store one or more data fields and pointer links inside each of the individual objects, depending on the needs of the required data structure.<\/p>\n

2.1 Node class in Linked List<\/h3>\n

In this section, we will discuss the node class used in defining a Singly Linked List.<\/p>\n

In the Case of Singly Linked List, the Node class usually contains 2 values,<\/p>\n

    \n
  1. Data Field, which contains the data stored in the current Node.<\/li>\n
  2. Pointer Field of type Node, which contains the address information of the next Node in the Linked List.<\/li>\n<\/ol>\n

    The following code snippet will show the structure of the Node Class in the Singly Linked List.<\/p>\n

    SinglyLinkedListNode.java<\/em><\/span><\/p>\n

    \n
    \npublic class SinglyLinkedListNode {\n    protected int data;\n    protected SinglyLinkedListNode next;\n\n    public SinglyLinkedListNode() {\n        next = null;\n        data = 0;\n    }\n\n    public SinglyLinkedListNode(int d, SinglyLinkedListNode n) {\n        data = d;\n        next = n;\n    }\n\n    public void setLinkNext(SinglyLinkedListNode n) {\n        next = n;\n    }\n\n\n    public SinglyLinkedListNode getLinkNext() {\n        return next;\n    }\n\n\n    public void setData(int d) {\n        data = d;\n    }\n\n    public int getData() {\n        return data;\n    }\n}\n<\/pre>\n<\/div>\n
    In the above code snippet, the next<\/code> is the pointer to the next node in the Singly Linked List and data<\/code> is the value stored in the current node of Singly Linked List. <\/p>\n
    2.2 Node class in Doubly Linked List and Binary Tree<\/h3>\n
    In this section we will discuss the node class used in defining a Doubly Linked List and Binary tree.<\/p>\n
    In case of Both DLL and Binary Tree, the Node class contains 3 values.<\/p>\n
    For Doubly Linked List, Node class usually have 3 values,<\/p>\n
      \n
    1. Data Field, which contains the data stored in the current Node.<\/li>\n
    2. Next Pointer Field of type Node, which contains the address information of the next Node in the Linked List.<\/li>\n
    3. Prev Pointer Field of type Node, which contains the address information of the previous Node in the Linked List.<\/li>\n<\/ol>\n
      Following Code snippet will show the structure of the Node Class in Doubly Linked List. <\/p>\n
      DoublyLinkedListNode.java<\/em><\/span><\/p>\n
      \n
      \npublic class DoublyLinkedListNode {\n    protected int data;\n    protected DoublyLinkedListNode next, prev;\n\n    public DoublyLinkedListNode() {\n        next = null;\n        prev = null;\n        data = 0;\n    }\n\n    public DoublyLinkedListNode(int d, DoublyLinkedListNode n, DoublyLinkedListNode p) {\n        data = d;\n        next = n;\n        prev = p;\n    }\n\n    public void setLinkNext(DoublyLinkedListNode n) {\n        next = n;\n    }\n\n    public void setLinkPrev(DoublyLinkedListNode p) {\n        prev = p;\n    }\n\n    public DoublyLinkedListNode getLinkNext() {\n        return next;\n    }\n\n    public DoublyLinkedListNode getLinkPrev() {\n        return prev;\n    }\n\n    public void setData(int d) {\n        data = d;\n    }\n\n    public int getData() {\n        return data;\n    }\n}\n<\/pre>\n<\/div>\n
      In the above code snippet, the next is the pointer to the next node and prev is the pointer to the previous node in the Doubly Linked List and data<\/code> is the value stored in the current node of Doubly Linked List. 
       
      <\/div> <\/div><\/p>\n
      For Binary tree, Node class usually have 3 values,<\/p>\n
        \n
      1. Data Field, which contains the data stored in the current Node.<\/li>\n
      2. Left Pointer Field of type Node, which contains the address information of the root Node of  Left Subtree in Binary Tree or null for leaf pointer.<\/li>\n
      3. Right Pointer Field of type Node, which contains the address information of the root Node of  Right Subtree in Binary Tree or null for leaf pointer.<\/li>\n<\/ol>\n
        The following Code snippet will show the structure of the Node Class in Binary Tree.<\/p>\n
        BinaryTreeNode.java<\/em><\/span><\/p>\n
        \n
        \nclass BinaryTreeNode {\n    int value;\n    BinaryTreeNode left;\n\n    public int getValue() {\n        return value;\n    }\n\n    public void setValue(int value) {\n        this.value = value;\n    }\n\n    public BinaryTreeNode getLeft() {\n        return left;\n    }\n\n    public void setLeft(BinaryTreeNode left) {\n        this.left = left;\n    }\n\n    public BinaryTreeNode getRight() {\n        return right;\n    }\n\n    public void setRight(BinaryTreeNode right) {\n        this.right = right;\n    }\n\n    BinaryTreeNode right;\n\n    BinaryTreeNode(int value) {\n        this.value = value;\n        right = null;\n        left = null;\n    }\n}\n<\/pre>\n<\/div>\n
        In the above code snippet, the right<\/code> is the pointer to the root of the right subtree node and left <\/code> is the pointer to the root of the left subtree of the Binary Tree and value<\/code> is the value stored in the current node of the Binary Tree.<\/p>\n
        2.3 Node class in N-Ary Tree and Trie<\/h3>\n
        In this section, we will discuss the node class used in defining an N-ary tree and Trie.<\/p>\n
        In the Case of the N-ary tree and Trie, the Node class usually contains 2 values,<\/p>\n
          \n
        1. Data Field, which contains the data stored in the current Node.<\/li>\n
        2. Pointer Field, which is an array of items of type Node, where each item contains the address information of the next Node in the Linked List.<\/li>\n<\/ol>\n
          The following Code snippet will show the structure of the Node Class in N-ary Tree and Trie Linked List.<\/p>\n
          NaryTreeNode.java<\/em><\/span><\/p>\n
          \n
          \nimport java.util.ArrayList;\nimport java.util.List;\n\npublic class NaryTreeNode {\n\n    public NaryTreeNode parentNode; \/\/ The parent of the current node\n    public List<NaryTreeNode> childList; \/\/ The children's of the current node\n    public String dataValue;\n\n    public NaryTreeNode getParentNode() {\n        return parentNode;\n    }\n\n    public void setParentNode(NaryTreeNode parentNode) {\n        this.parentNode = parentNode;\n    }\n\n    public List<NaryTreeNode> getChildList() {\n        return childList;\n    }\n\n    public void setChildList(List<NaryTreeNode> childList) {\n        this.childList = childList;\n    }\n\n    public String getDataValue() {\n        return dataValue;\n    }\n\n    public void String(String dataValue) {\n        this.dataValue = dataValue;\n    }\n\n    public static int getMaxNumberOfChildren() {\n        return maxNumberOfChildren;\n    }\n\n    public static void setMaxNumberOfChildren(int maxNumberOfChildren) {\n        NaryTreeNode.maxNumberOfChildren = maxNumberOfChildren;\n    }\n\n    public static int maxNumberOfChildren; \/\/ Equal to the n-arity;\n\n    public NaryTreeNode(String dataValue) {\n        this.dataValue = dataValue;\n        childList = new ArrayList<NaryTreeNode>(maxNumberOfChildren);\n    }\n\n    public void addChild(NaryTreeNode childNaryTreeNode, int position) throws Exception {\n        if (position >= maxNumberOfChildren - 1) {\n            throw new Exception("Max number of childeren reached");\n        } else {\n            System.out.println("this.children=" + this.childList);\n            if (this.childList.get(position) != null) {\n                \/\/ There is already a child node on this position; throw some error;\n            } else {\n                childNaryTreeNode.parentNode = this;\n                this.childList.set(position, childNaryTreeNode);\n            }\n        }\n    }\n}\n<\/pre>\n<\/div>\n
          In the above code snippet, the parentNode stores the parent information of the current node, childList stores the list of all the children of the current node and dataValue<\/code> stores the information stored in the current node.<\/p>\n
          TrieNode.java<\/em><\/span><\/p>\n
          \n
          \npublic class TrieNode {\n    final int ALPHABET_SIZE = 26;\n    TrieNode[] trieChildList = new TrieNode[ALPHABET_SIZE];\n\n    boolean isEndOfWord; \/\/ used in implementation of Prefix Search, signifies the end of word.\n\n    public TrieNode[] getTrieChildList() {\n        return trieChildList;\n    }\n\n    public void setTrieChildList(TrieNode[] trieChildList) {\n        this.trieChildList = trieChildList;\n    }\n\n    public boolean isEndOfWord() {\n        return isEndOfWord;\n    }\n\n    public void setEndOfWord(boolean endOfWord) {\n        isEndOfWord = endOfWord;\n    }\n\n    TrieNode() {\n        isEndOfWord = false;\n        for (int i = 0; i < ALPHABET_SIZE; i++)\n            trieChildList[i] = null;\n    }\n}\n\n<\/pre>\n<\/div>\n
          In the above code snippet, the trieChildList<\/code> is the list of all the child nodes of the current node in Trie.<\/p>\n
          4. Applications of Node class<\/h2>\n
          During the course of this article, we have seen various use-case featuring the Node class. Java Node class is actually being used as a generic name for any object template which is used in a building block for any non-sequential Data structure.<\/p>\n
          5. More articles<\/h2>\n