pl.szczepanik.silencio.converters.NumberSequenceConverter Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of silencio Show documentation

Silencio is a Java library for transforming and converting XML, JSON, Properties, YAML and other formats. It is applicable for most operations such as obfuscation, encryption, minimisation (minifying), anonymous. Library is fully customizable and extensible.

The newest version!

package pl.szczepanik.silencio.converters;

import java.util.HashMap;
import java.util.Map;

import pl.szczepanik.silencio.api.Converter;
import pl.szczepanik.silencio.core.Key;
import pl.szczepanik.silencio.core.Value;

/**
 * Converter that changes each passed value into number in way that the same passed value has the same number.
 * 
 * @author Damian Szczepanik (damianszczepanik@github)
 */
public class NumberSequenceConverter implements Converter {

    // Reserved for null value
    private static final int NULL_INDEX = 0;

    /**
     * Keeps passed values and corresponding numbers;
     */
    private final Map values = new HashMap<>();

    /**
     * Number that can be assigned to new/next passed not indexed value.
     */
    private int availableIndex;

    @Override
    public Value convert(Key key, Value value) {
        // querying by null value is not good idea so for null value return reserved number
        if (value.getValue() == null) {
            return new Value(NULL_INDEX);
        }

        Integer index = values.get(value.getValue());
        if (index != null) {
            return new Value(index);
        } else {
            index = availableIndex;
            values.put(value.getValue(), availableIndex);
            nextIndex();
            return new Value(index);
        }
    }

    @Override
    public void init() {
        values.clear();
        availableIndex = NULL_INDEX;
        nextIndex();
    }

    private void nextIndex() {
        availableIndex++;
    }
}