java - hashCode 冲突将两个不同的词放在同一位置

Question

我应该用哈希表实现一个接口(interface)。问题是我得到了错误的输出，这是由于碰撞(据我了解)。我并没有完全独立地编写这段代码，我一直在寻求帮助。我不是 Java 的大师，我的类(class)还很早，所以这对我来说很难，所以请耐心等待。

到目前为止，这是我的代码:

runStringDictionary.java

import java.io.BufferedReader;
import java.io.FileReader;

public class runStringDictionary {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub

        if (args.length == 0 || args.length > 1) {
            System.out.println("Syntax to run the program: java runStringDictionary <inputFile>");
        }
        if (args.length == 1) {
            try {

                Dictionary myDictionary = new Dictionary(); //Initialize a Dictionary to store input words
                BufferedReader br = new BufferedReader(new FileReader(args[0])); //Read the text file input
                String line;

                while ((line = br.readLine()) != null) {//Read each line
                    String[] strArray = line.split(" "); //Separate each word in the line and store in another Array
                    for (int i = 0; i < strArray.length; i++) { //Loop over the Array
                        if (myDictionary.contains(strArray[i])) { //Check if word exists in the dictionary
                            myDictionary.remove(strArray[i]); //if it does remove it
                        } else {
                            myDictionary.add(strArray[i]); //if it doesn't then add it
                        }
                    }
                }//while loop ends

                //print the contents of myDictionary
                for (int i = 0; i < 25; i++) {
                    if (myDictionary.table[i] != null) {
                        System.out.println(myDictionary.table[i]);
                    }
                }

            } catch (Exception e) {
                System.out.println("Error found : " + e);
            }
        }
    }
}

StringDictionary.java

public interface StringDictionary {

    public boolean add(String s);

    public boolean remove(String s);

    public boolean contains(String s);
}

Dictionary.java

public class Dictionary implements StringDictionary {
    private int tableSize = 25;
    Object[] table;

    // constructor
    Dictionary() {
        this.table = new Object[this.tableSize];
    }

    @Override
    public boolean add(String s) {
        // TODO Auto-generated method stub
        int hashCode = s.hashCode() % this.tableSize;
        if (!this.contains(s)) {
            this.table[hashCode] = s;
        }
        return false;
    }

    @Override
    public boolean remove(String s) {
        // TODO Auto-generated method stub
        int hashCode = s.hashCode() % this.tableSize;
        if (this.contains(s)) {
            this.table[hashCode] = null;
            return true;
        }
        return false;
    }

    @Override
    public boolean contains(String s) {
        // TODO Auto-generated method stub
        int hashCode = s.hashCode() % this.tableSize;
        if (table[hashCode] != null) {
            if (table[hashCode].equals(s))
                return true;
        }
        return false;
    }
}

Answer 1

Hashcode 冲突是意料之中的，也是正常的；哈希码用于缩小潜在匹配范围，然后必须检查这些潜在匹配的规范相等性。