包含不区分大小写的方法区分大小写?

时间:2014-10-26 18:44:46

标签: java string arraylist contains case-insensitive

有没有办法忽略contains()方法的情况,但同时让代码片段或多或少相同?

/**
 * This method returns a list of all words from the dictionary that include the given substring.
 *
 */
public ArrayList<String> wordsContaining(String text)
{
    int index = 0;
    ArrayList<String> wordsContaining = new ArrayList<String>();      
    while(index<words.size())
    {
        if((words.get(index).contains(text)))
        {
            wordsContaining.add(words.get(index));
        }
        index++;
    }
    return wordsContaining;
}

这是整个SpellChecker类:​​

public class SpellChecker
{
     private ArrayList<String> words;
     private DictReader reader;

    /**
     * Constructor for objects of class SpellChecker
     */

public SpellChecker()
{
    reader = new DictReader("words.txt");
    words = reader.getDictionary();
}

/**
 * This method returns the number of words in the dictionary.
 * 
 */
public int numberOfWords()
{
    return words.size();
}

/**
 * This method returns true, if (and only if) the given word is found in the dictionary.
 *
 */
public boolean isKnownWord(String word)
{
    int index =0;
    while(index < words.size())
    {
        if(words.get(index).equals(word))
        {
            return true;
        }
        index++;
    }
    return false;
}

/**
 * This method returns true if (and only if) all words in the given wordList are found in the dictionary.
 */
public boolean allKnown(ArrayList<String> wordList)
{
   for(String word : wordList)
   {
       if(isKnownWord(word))
       {
           return true;
        }

   }
    return false;
}

/**
 * This method tests the allKnown method.
 */
public boolean testAllKnown()
{
    ArrayList<String> testWords = new ArrayList<String>();
    testWords.add("Abu");
    testWords.add("Chou");
    if(allKnown(testWords))
    {
        return true;
    }
    else
    {
        return false;
    }

}

/**
 * This method returns a list of all words from the dictionary that start with the given prefix.
 *
 */
public ArrayList<String> wordsStartingWith(String prefix)
{
    int index = 0;
    ArrayList<String> wordsStartingWith = new ArrayList<String>();
    while(index<words.size())
    {
        if(words.get(index).startsWith(prefix))
        {
            wordsStartingWith.add(words.get(index));

        }
        index++;
    }
    return wordsStartingWith;
}    

/**
 * This method returns a list of all words from the dictionary that include the given substring.
 *
 */
public ArrayList<String> wordsContaining(String text)
{
    int index = 0;
    ArrayList<String> wordsContaining = new ArrayList<String>();      
    while(index<words.size())
    {
        if((words.get(index).contains(text)))
        {
            wordsContaining.add(words.get(index));
        }
        index++;
    }
    return wordsContaining;
}

DicReader类只需要一个给定文本文件并从中“制作”一个字典。我会把它放在以防万一:

public class DictReader
{
  private ArrayList<String> dict;
  private String filename;

  /**
   * Create a DictReader instance from a file.
   */

public DictReader(String filename)
{
    loadDictionary(filename);
    this.filename = filename;
}

/**
 * Return the dictionary as a list of words.
 */
public ArrayList<String> getDictionary()
{
    return dict;
}

/**
 * Accept a new dictionary and save it under the same name. Use the new
 * one as our dictionary from now on.
 */
public void save(ArrayList<String> dictionary)
{
    try {
        FileWriter out = new FileWriter(filename);
        for(String word : dictionary) {
            out.write(word);
            out.write("\n");
        }
        out.close();
        dict = dictionary;
    }
    catch(IOException exc) {
        System.out.println("Error writing dictionary file: " + exc);
    }
}

/**
 * Load the dictionary from disk and store it in the 'dict' field.
 */
private void loadDictionary(String filename)
{
    dict = new ArrayList<String>();

    try {
        BufferedReader in = new BufferedReader(new FileReader(filename));
        String word = in.readLine();
        while(word != null) {
            dict.add(word);
            word = in.readLine();
        }
        in.close();
    }
    catch(IOException exc) {
        System.out.println("Error reading dictionary file: " + exc);
    }
}
}

所以问题是我需要检查天气或者不是给定的单词包含我称之为“text”的文本片段/子字符串,但字符串的contains方法区分大小写。我已经做了一些研究,并注意到要删除区分大小写,你必须导入一个特定的库,新的包含方法的语法是不同的,它不能很好地与我目前的代码。我当时想知道是否有一种方法可以使contains()不区分大小写,但保留了代码的结构。

1 个答案:

答案 0 :(得分:1)

将两个字符串设为小写(或大写)

public ArrayList<String> wordsContaining(String text)
{
    int index = 0; 
    text = text.toLowerCase();
    ArrayList<String> wordsContaining = new ArrayList<String>();      
    while(index<words.size())
    {
        if((words.get(index).toLowerCase().contains(text)))
        {
            wordsContaining.add(words.get(index));
        }
        index++;
    }
    return wordsContaining;
}