Converts a note name in scientific pitch notation into its MIDI number - Java javax.sound.midi

Java examples for javax.sound.midi:MidiSystem

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Description

Converts a note name in scientific pitch notation into its MIDI number

Demo Code


//package com.java2s;

import java.util.HashMap;

import java.util.Map;
import java.util.regex.MatchResult;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class Main {
    private static final Map<String, Integer> _baseMap = new HashMap<>();
    private static final Pattern NOTE_FORMAT = Pattern
            .compile("([A-G])([#b]?)(-?\\d{1,2})");

    /**//from ww w .  j  ava 2s .  c  o  m
     * Converts a note name in scientific pitch notation into its MIDI number
     * @param noteName - the name of the note in scientific pitch notation
     * (e.g., A4, C#3, Gb5)
     * @return the MIDI number of the given note
     */
    public static int noteNameToNumber(String noteName) {
        final Matcher matcher = NOTE_FORMAT.matcher(noteName);
        if (!matcher.matches())
            throw new IllegalArgumentException(
                    "Given note name didn't match pattern");

        final MatchResult result = matcher.toMatchResult();
        final String pitchClass = result.group(1);
        final String sharpFlat = result.group(2);
        final int octave = Integer.parseInt(result.group(3));

        final int accidental;
        if (sharpFlat.isEmpty())
            accidental = 0;
        else if (sharpFlat.charAt(0) == 'b')
            accidental = -1;
        else
            accidental = 1;

        return _baseMap.get(pitchClass).intValue() + accidental
                + (12 * (octave + 1));
    }
}

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