Java实现hash表，线性探测，二次探测，再哈希法，链表法

不废话，直接上代码，关键地方有注释。

package test2;

class DataItem{
	private int key;
	public DataItem(int data){
		this.key = data;
	}
	public int getKey(){
		return this.key;
	}
}
public class HashTable {
	private DataItem[] dataArray;
	private int arraySize;
	private static DataItem noItem;
	
	static
	{
		noItem = new DataItem(-1);
	}
	
	public HashTable(int size){
		if(size > 0){
			arraySize = size;
			dataArray = new DataItem[arraySize];
		}
	}
	public void insertDataItem(int key){//假设hash表不满
		DataItem data = new DataItem(key);
		int hashCode = getHashCode(key);
		while(dataArray[hashCode] != null && dataArray[hashCode] != noItem){//
			++hashCode;				//线性探测，会产生聚集现象
			hashCode %= arraySize;
		}
		dataArray[hashCode] = data;
		
	}
	public void insertSecondaryDataItem(int key){
		DataItem data = new DataItem(key);
		int hashCode = getHashCode(key);
		int stepSize,i=1;