java开放地址法和链地址法解决hash冲突的方法示例

public class Info {
	private String key;			//关键字，或者能标识对象的唯一属性
	private String name;		//值域
	
	public Info(String key, String name) {
		this.key = key;
		this.name = name;
	}

	public String getKey() {
		return key;
	}

	public void setKey(String key) {
		this.key = key;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}
}

/**
 * 模拟hashMap
 *
 */
public class HashTable {
	
	private Info[] arr;
	
	/**
	 * 默认的构造方法
	 */
	public HashTable() {
		arr = new Info[100];
	}
	
	/**
	 * 指定数组初始化大小
	 */
	public HashTable(int maxSize) {
		arr = new Info[maxSize];
	}
	
	/**
	 * 插入数据
	 */
	public void insert(Info info) {
		//获得关键字
		String key = info.getKey();
		//关键字所自定的哈希数
		int hashVal = hashCode(key);
		//如果这个索引已经被占用，而且里面是一个未被删除的数据
		while(arr[hashVal] != null && arr[hashVal].getName() != null) {
			//进行递加，避免漏找
			++hashVal;
			//循环
			hashVal %= arr.length;
		}
		arr[hashVal] = info;
	}
	
	/**
	 * 查找数据
	 */
	public Info find(String key) {
		int hashVal = hashCode(key);
		while(arr[hashVal] != null) {
			if(arr[hashVal].getKey().equals(key)) {
				return arr[hashVal];
			}
			++hashVal;
			hashVal %= arr.length;
		}
		return null;
	}
	
	/**
	 * 删除数据
	 */
	public Info delete(String key) {
		int hashVal = hashCode(key);
		//循环查找，数组中下标为hashVal的值，没有找到返回null
		while(arr[hashVal] != null) {
			if(arr[hashVal].getKey().equals(key)) {
				Info tmp = arr[hashVal];
				tmp.setName(null);
				return tmp;
			}
			++hashVal;			//由于数组的值是连续的，为了避免漏找，需要依次往下找
			hashVal %= arr.length;
		}
		return null;
	}
	
	/**
	 * 获得关键字的hash值，也可以自定义
	 */
	public int hashCode(String key) {
		
		BigInteger hashVal = new BigInteger("0");
		BigInteger pow27 = new BigInteger("1");
		for(int i = key.length() - 1; i >= 0; i--) {
			int letter = key.charAt(i) - 96;
			BigInteger letterB = new BigInteger(String.valueOf(letter));
			hashVal = hashVal.add(letterB.multiply(pow27));
			pow27 = pow27.multiply(new BigInteger(String.valueOf(27)));
		}
		return hashVal.mod(new BigInteger(String.valueOf(arr.length))).intValue();
	}
}

public class Info {
	
	private String key;
	private String name;
	
	public Info(String key, String name) {
		this.key = key;
		this.name = name;
	}

	public String getKey() {
		return key;
	}

	public void setKey(String key) {
		this.key = key;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}
	
	
	
}

public class Node {

	// 数据域
	public Info info;
	// 指针域,指向对下一个节点引用
	public Node next;

	public Node(Info info) {
		this.info = info;
	}

}

/**
 * 模拟linkedList
 * 
 * @author asus
 *
 */
public class LinkList {

	// 头结点
	private Node first;

	public LinkList() {
		first = null;
	}

	// 插入一个节点
	public void insertFirst(Info info) {
		Node node = new Node(info);
		node.next = first;
		first = node;
	}

	// 删除一个节点，在头结点后进行删除
	public Node deleteFirst() {
		Node temp = first;
		first = temp.next;
		return temp;
	}

	/**
	 * 查找方法
	 */
	public Node find(String key) {
		Node current = first;
		while (!key.equals(current.info.getKey())) {
			if (current.next == null) {
				return null;
			}
			current = current.next;
		}
		return current;
	}

	/**
	 * 删除方法
	 */
	public Node delete(String key) {
		Node current = first;
		Node previous = first;
		while (!key.equals(current.info.getKey())) {
			if (current.next == null) {
				return null;
			}
			previous = current;
			current = current.next;
		}

		if (current == first) {
			first = first.next;
		} else {
			previous.next = current.next;
		}
		return current;

	}

}

public class HashTable {

	private LinkList[] arr;

	/**
	 * 默认的构造方法
	 */
	public HashTable() {
		arr = new LinkList[100];
	}

	/**
	 * 指定数组初始化大小
	 */
	public HashTable(int maxSize) {
		arr = new LinkList[maxSize];
	}

	/**
	 * 插入数据
	 */
	public void insert(Info info) {
		String key = info.getKey();
		// 获取关键字的自定义hash函数
		int hashVal = hashCode(key);

		if (arr[hashVal] == null) {		//如果数组某个单元的位置为空，则需要重新构造一个linkList
			arr[hashVal] = new LinkList();
		}
		arr[hashVal].insertFirst(info);
	}

	/**
	 * 查找数据
	 */
	public Info find(String key) {
		int hashVal = hashCode(key);
		return arr[hashVal].find(key).info;
	}
	
	/**
	 * 删除数据
	 */
	public Info delete(String key){
		int hashVal = hashCode(key);
		return arr[hashVal].delete(key).info;
	}
	

	/**
	 * 自定义计算hash的函数
	 */
	public int hashCode(String key) {

		BigInteger hashVal = new BigInteger("0");
		BigInteger pow27 = new BigInteger("1");
		for (int i = key.length() - 1; i >= 0; i--) {
			int letter = key.charAt(i) - 96;
			BigInteger letterB = new BigInteger(String.valueOf(letter));
			hashVal = hashVal.add(letterB.multiply(pow27));
			pow27 = pow27.multiply(new BigInteger(String.valueOf(27)));
		}
		return hashVal.mod(new BigInteger(String.valueOf(arr.length))).intValue();
	}

}