public class HashTable{    private String[] name;    //关键字    private int sum;    //容量    public static void main(String[] args){    //测试         HashTable ht = new HashTable();         ht.add("chenhaitao");         ht.add("zhongcheng");         ht.add("baiyudong");         ht.add("huangshiyao");         ht.add("djflkd");         ht.add("gg");         System.out.println(ht.contains("baiyudong"));         ht.remove("huangshiyao");         System.out.println(ht.contains("huangshiyao"));         ht.print();    }   public HashTable(){             //初始化，初始容量是10个       name = new String[10];       sum = 0;   }   public int hash1(String s){                                       //哈希函数         return Math.abs(s.hashCode())%name.length;   }   public int hash2(String s){                                     //处理冲突的哈希函数       int result = Math.abs(s.hashCode())%(name.length-1);       System.out.println(s+"--"+result);       if(result%2==0){           return result + 1;       }    return result;   }   public boolean contains(String s){                  //哈希表里面是否包含字符串s       int start = hash1(s);       int i = start;       while (name[i] != null){            if(name[i].equals(s)){                return true;            }         i = (i + hash2(s))%name.length;         if(i == start){              return false;         }       }    return false;   }   public void add(String s){        if(sum>=name.length/2){             this.rehash();        }       int start = hash1(s);       int i = start;      while(name[i] != null){          if(s.equals(name[i])){               return;          }        i = (i + hash2(s))%name.length;       if(i == start){           return;        }      }     name[i] = s;     sum ++;   }    public void rehash(){                              //扩建一个哈希表为原表的两倍，把原来的哈希表添加到新表中        HashTable ht = new HashTable();        ht.name = new String[this.name.length * 2];        for(int i = 0; i < this.name.length; i ++){                if((this.name[i] != null)){                    ht.add(this.name[i]);               }        }      this.name = ht.name;      this.sum = ht.sum;    }   public void remove(String s){                     //删除某个元素          if(this.contains(s)){               int i = this.getValue(s);               this.name[i] = null;          }   }   public int getValue(String s){                //得到s在哈希表中的位置     int start = this.hash1(s);     int i = start;     while(this.name[i] != null){        if(this.name[i].equals(s)){            return i;        }      i = (i + this.hash2(s))%this.name.length;     if(i == start){       return -1;      }    }   return -1;   }   public void print(){                       //输出哈希表中所有元素      for(int i = 0; i < name.length; i ++){         System.out.println(i+":"+name[i]);     }   } public int size(){          //哈希表存储元素的个数    return this.sum;  } public int length(){            //哈希表的长度     return this.name.length;  } }