Java HashTable 구현

Java HashTable 을 구현해 보았다. 

Key 충돌 알고리즘은 Chaining 리스트를 통해서 해결했다.

package com.study;
 
import java.util.LinkedList;
 
class HashTable {
    LinkedList<Node>[] data;
    
    public HashTable(int size) {
        this.data = new LinkedList[size];
    }
    
    int getHashCode(String key) {
        int hashCode = 0;
        for(char c : key.toCharArray()) {
            
            hashCode += c;
        }
        
        return hashCode;
    }
    
    int convertToIndex(int hashCode) {
        
        return hashCode % data.length;
    }
    
    Node searchKey(LinkedList<Node> list, String key) {
        if(list == null) return null;
        
        for(Node node : list) {
            if(node.key.equals(key)) {
                
                return node;
            }
        }
        
        return null;
    }
    
    void put(String key, String value) {
        int hashCode = getHashCode(key);
        int index = convertToIndex(hashCode);
        
        LinkedList<Node> list = data[index];
        
        if(list == null) {
            list = new LinkedList<Node>();
            data[index] = list;
        }
        
        Node node = searchKey(list, key);
        
        if(node == null) {
            list.addLast(new Node(key, value));
        } else {
            node.setValue(value);
        }
    }
    
    public String get(String key) {
        int hashCode = getHashCode(key);
        int index = convertToIndex(hashCode);
        LinkedList<Node> list = data[index];
        Node node = searchKey(list, key);
        
        return node == null ? "Not found" : node.getValue();
    }
    
    class Node {
        String key;
        String value;
        
        public Node(String key, String value) {
            this.key = key;
            this.value = value;
        }
        
        public String getValue() {
            
            return this.value;
        }
        
        public void setValue(String value) {
            
            this.value = value;
        }
    }
}

public class Test {
    public static void main(String[] args) {
        HashTable ht = new HashTable(3);
        ht.put("sung", "She is pretty");
        ht.put("jin", "She is model");
        ht.put("hee", "She is angel");
        ht.put("min", "She is cute");
        
        System.out.println(ht.get("sung"));
        System.out.println(ht.get("jin"));
        System.out.println(ht.get("hee"));
        System.out.println(ht.get("min"));
        System.out.println(ht.get("jae"));
    }
}