Advise to create a translator in Java

Question

I want to make a translator ex: English to Spanish.

I want to translate a large text with a map for the translation.

HashMap <String, Object> hashmap = new HashMap <String, Object>();
hashmap.put("hello", "holla"); 
.
.
.

Witch object should I use to handle my inital text of 1000 words? A String or StringBuilder is fine ?

How can I do a large replace? Without iterate each word with each element of the map ?

I don't want take each word of the string, and see there is a match in my map

Maybe a multimap with the first letter of the word?

If you have any answer or advise thank you

Answer 1

Here is an example implementation:

import java.io.*;
import java.util.*;

public class Translator {

    public enum Language {
        EN, ES
    }

    private static final String TRANSLATION_TEMPLATE = "translation_%s_%s.properties";
    private final Properties translations = new Properties();

    public Translator(Language from, Language to) {
        String translationFile = String.format(TRANSLATION_TEMPLATE, from, to);
        try (InputStream is = getClass().getResourceAsStream(translationFile)) {
            translations.load(is);
        } catch (final IOException e) {
            throw new RuntimeException("Could not read: " + translationFile, e);
        }
    }

    private String[] translate(String text) {
        String[] source = normalizeText(text);
        List<String> translation = new ArrayList<>();
        for (String sourceWord : source) {
            translation.add(translateWord(sourceWord));
        }
        return translation.toArray(new String[source.length]);
    }

    private String translateWord(String sourceWord) {
        Object value = translations.get(sourceWord);
        String translatedWord;
        if (value != null) {
            translatedWord = String.valueOf(value);
        }
        else {
            // if no translation is found, add the source word with a question mark
            translatedWord = sourceWord + "?";
        }
        return translatedWord;
    }

    private String[] normalizeText(String text) {
        String alphaText = text.replaceAll("[^A-Za-z]", " ");
        return alphaText.split("\\s+");
    }

    public static void main(final String[] args) {
        final Translator translator = new Translator(Language.EN, Language.ES);
        System.out.println(Arrays.toString(translator.translate("hello world!")));
    }
}

And put a file called 'translation_EN_ES.properties' on your classpath (e.g. src/main/resources) with:

hello=holla
world=mundo