223 lines
8.9 KiB
Java
223 lines
8.9 KiB
Java
/*
|
|
* QR Code generator library (Java)
|
|
*
|
|
* Copyright (c) 2016 Project Nayuki
|
|
* https://www.nayuki.io/page/qr-code-generator-library
|
|
*
|
|
* (MIT License)
|
|
* Permission is hereby granted, free of charge, to any person obtaining a copy of
|
|
* this software and associated documentation files (the "Software"), to deal in
|
|
* the Software without restriction, including without limitation the rights to
|
|
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
|
|
* the Software, and to permit persons to whom the Software is furnished to do so,
|
|
* subject to the following conditions:
|
|
* - The above copyright notice and this permission notice shall be included in
|
|
* all copies or substantial portions of the Software.
|
|
* - The Software is provided "as is", without warranty of any kind, express or
|
|
* implied, including but not limited to the warranties of merchantability,
|
|
* fitness for a particular purpose and noninfringement. In no event shall the
|
|
* authors or copyright holders be liable for any claim, damages or other
|
|
* liability, whether in an action of contract, tort or otherwise, arising from,
|
|
* out of or in connection with the Software or the use or other dealings in the
|
|
* Software.
|
|
*/
|
|
|
|
package io.nayuki.qrcodegen;
|
|
|
|
import java.util.Arrays;
|
|
import java.util.regex.Pattern;
|
|
|
|
|
|
/**
|
|
* Represents a character string to be encoded in a QR Code symbol. Each segment has
|
|
* a mode, and a sequence of characters that is already encoded as a sequence of bits.
|
|
* Instances of this class are immutable.
|
|
* <p>This segment class imposes no length restrictions, but QR Codes have restrictions.
|
|
* Even in the most favorable conditions, a QR Code can only hold 7089 characters of data.
|
|
* Any segment longer than this is meaningless for the purpose of generating QR Codes.</p>
|
|
*/
|
|
public final class QrSegment {
|
|
|
|
/*---- Static factory functions ----*/
|
|
|
|
/**
|
|
* Returns a segment representing the specified binary data encoded in byte mode.
|
|
* @param data the binary data
|
|
* @return a segment containing the data
|
|
* @throws NullPointerException if the array is {@code null}
|
|
*/
|
|
public static QrSegment makeBytes(byte[] data) {
|
|
if (data == null)
|
|
throw new NullPointerException();
|
|
return new QrSegment(Mode.BYTE, data.length, data, data.length * 8);
|
|
}
|
|
|
|
|
|
/**
|
|
* Returns a segment representing the specified string of decimal digits encoded in numeric mode.
|
|
* @param digits a string consisting of digits from 0 to 9
|
|
* @return a segment containing the data
|
|
* @throws NullPointerException if the string is {@code null}
|
|
* @throws IllegalArgumentException if the string contains non-digit characters
|
|
*/
|
|
public static QrSegment makeNumeric(String digits) {
|
|
if (digits == null)
|
|
throw new NullPointerException();
|
|
if (!NUMERIC_REGEX.matcher(digits).matches())
|
|
throw new IllegalArgumentException("String contains non-numeric characters");
|
|
|
|
BitBuffer bb = new BitBuffer();
|
|
int i;
|
|
for (i = 0; i + 3 <= digits.length(); i += 3) // Process groups of 3
|
|
bb.appendBits(Integer.parseInt(digits.substring(i, i + 3)), 10);
|
|
int rem = digits.length() - i;
|
|
if (rem > 0) // 1 or 2 digits remaining
|
|
bb.appendBits(Integer.parseInt(digits.substring(i)), rem * 3 + 1);
|
|
return new QrSegment(Mode.NUMERIC, digits.length(), bb.getBytes(), bb.bitLength());
|
|
}
|
|
|
|
|
|
/**
|
|
* Returns a segment representing the specified text string encoded in alphanumeric mode. The characters allowed are:
|
|
* 0 to 9, A to Z (uppercase only), space, dollar, percent, asterisk, plus, hyphen, period, slash, colon.
|
|
* @param text a string of text, with only certain characters allowed
|
|
* @return a segment containing the data
|
|
* @throws NullPointerException if the string is {@code null}
|
|
* @throws IllegalArgumentException if the string contains non-encodable characters
|
|
*/
|
|
public static QrSegment makeAlphanumeric(String text) {
|
|
if (text == null)
|
|
throw new NullPointerException();
|
|
if (!ALPHANUMERIC_REGEX.matcher(text).matches())
|
|
throw new IllegalArgumentException("String contains unencodable characters in alphanumeric mode");
|
|
|
|
BitBuffer bb = new BitBuffer();
|
|
int i;
|
|
for (i = 0; i + 2 <= text.length(); i += 2) { // Process groups of 2
|
|
int temp = ALPHANUMERIC_ENCODING_TABLE[text.charAt(i) - ' '] * 45;
|
|
temp += ALPHANUMERIC_ENCODING_TABLE[text.charAt(i + 1) - ' '];
|
|
bb.appendBits(temp, 11);
|
|
}
|
|
if (i < text.length()) // 1 character remaining
|
|
bb.appendBits(ALPHANUMERIC_ENCODING_TABLE[text.charAt(i) - ' '], 6);
|
|
return new QrSegment(Mode.ALPHANUMERIC, text.length(), bb.getBytes(), bb.bitLength());
|
|
}
|
|
|
|
|
|
|
|
/*---- Instance fields ----*/
|
|
|
|
/** The mode indicator for this segment. Never {@code null}. */
|
|
public final Mode mode;
|
|
|
|
/** The length of this segment's unencoded data, measured in characters. Always zero or positive. */
|
|
public final int numChars;
|
|
|
|
/** The bits of this segment packed into a byte array in big endian. Accessed through {@link getByte(int)}. Not {@code null}. */
|
|
private final byte[] data;
|
|
|
|
/** The length of this segment's encoded data, measured in bits. Satisfies 0 ≤ {@code bitLength} ≤ {@code data.length} × 8. */
|
|
public final int bitLength;
|
|
|
|
|
|
/*---- Constructor ----*/
|
|
|
|
/**
|
|
* Creates a new QR Code data segment with the specified parameters and data.
|
|
* @param md the mode, which is not {@code null}
|
|
* @param numCh the data length in characters, which is non-negative
|
|
* @param bitLen the data length in bits, which is non-negative
|
|
* @param b the bits packed into bytes, which is not {@code null}
|
|
* @throws NullPointerException if the mode or array is {@code null}
|
|
* @throws IllegalArgumentException if the character count or bit length are negative or invalid
|
|
*/
|
|
public QrSegment(Mode md, int numCh, byte[] b, int bitLen) {
|
|
if (md == null || b == null)
|
|
throw new NullPointerException();
|
|
if (numCh < 0 || bitLen < 0 || bitLen > b.length * 8L)
|
|
throw new IllegalArgumentException("Invalid value");
|
|
mode = md;
|
|
numChars = numCh;
|
|
data = Arrays.copyOf(b, (bitLen + 7) / 8); // Trim to precise length and also make defensive copy
|
|
bitLength = bitLen;
|
|
}
|
|
|
|
|
|
/*---- Method ----*/
|
|
|
|
/**
|
|
* Returns the data byte at the specified index.
|
|
* @param index the index to retrieve from, satisfying 0 ≤ {@code index} < ceil({@code bitLength} ÷ 8)
|
|
* @return the data byte at the specified index
|
|
* @throws IndexOutOfBoundsException if the index is out of bounds
|
|
*/
|
|
public byte getByte(int index) {
|
|
if (index < 0 || index > data.length)
|
|
throw new IndexOutOfBoundsException();
|
|
return data[index];
|
|
}
|
|
|
|
|
|
/*---- Constants ----*/
|
|
|
|
/** Can test whether a string is encodable in numeric mode (such as by using {@link #makeNumeric(String)}). */
|
|
public static final Pattern NUMERIC_REGEX = Pattern.compile("[0-9]*");
|
|
|
|
/** Can test whether a string is encodable in alphanumeric mode (such as by using {@link #makeAlphanumeric(String)}). */
|
|
public static final Pattern ALPHANUMERIC_REGEX = Pattern.compile("[A-Z0-9 $%*+./:-]*");
|
|
|
|
private static final byte[] ALPHANUMERIC_ENCODING_TABLE = {
|
|
// SP, !, ", #, $, %, &, ', (, ), *, +, ,, -, ., /, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, :, ;, <, =, >, ?, @, // ASCII codes 32 to 64
|
|
36, -1, -1, -1, 37, 38, -1, -1, -1, -1, 39, 40, -1, 41, 42, 43, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 44, -1, -1, -1, -1, -1, -1, // Array indices 0 to 32
|
|
10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, // Array indices 33 to 58
|
|
// A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z, // ASCII codes 65 to 90
|
|
};
|
|
|
|
|
|
|
|
/*---- Public helper enumeration ----*/
|
|
|
|
/**
|
|
* The mode field of a segment. Immutable. Provides methods to retrieve closely related values.
|
|
*/
|
|
public enum Mode {
|
|
// Constants.
|
|
NUMERIC (0x1, 10, 12, 14),
|
|
ALPHANUMERIC(0x2, 9, 11, 13),
|
|
BYTE (0x4, 8, 16, 16),
|
|
KANJI (0x8, 8, 10, 12);
|
|
|
|
|
|
/*-- Fields --*/
|
|
|
|
/** An unsigned 4-bit integer value (range 0 to 15) representing the mode indicator bits for this mode object. */
|
|
public final int modeBits;
|
|
|
|
private final int[] numBitsCharCount;
|
|
|
|
|
|
// Constructor.
|
|
private Mode(int mode, int... ccbits) {
|
|
this.modeBits = mode;
|
|
numBitsCharCount = ccbits;
|
|
}
|
|
|
|
|
|
/*-- Method --*/
|
|
|
|
/**
|
|
* Returns the bit width of the segment character count field for this mode object at the specified version number.
|
|
* @param ver the version number, which is between 1 to 40, inclusive
|
|
* @return the number of bits for the character count, which is between 8 to 16, inclusive
|
|
* @throws IllegalArgumentException if the version number is out of range
|
|
*/
|
|
public int numCharCountBits(int ver) {
|
|
if ( 1 <= ver && ver <= 9) return numBitsCharCount[0];
|
|
else if (10 <= ver && ver <= 26) return numBitsCharCount[1];
|
|
else if (27 <= ver && ver <= 40) return numBitsCharCount[2];
|
|
else throw new IllegalArgumentException("Version number out of range");
|
|
}
|
|
}
|
|
|
|
}
|