msb-public
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QR-Code-generator
mirror of https://github.com/nayuki/QR-Code-generator
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pull/90/head^2
jaemin7666 5 years ago
parent b4a141b111
commit 112cf4a538
1 changed files with 68 additions and 41 deletions
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java/src/main/java/io/nayuki/qrcodegen/QrSegment.java
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@ -29,14 +29,12 @@ import java.util.List;
import java.util.Objects;
import java.util.regex.Pattern;
import QrSegment.Mode;
/**
* A segment of character/binary/control data in a QR Code symbol.
* Instances of this class are immutable.
* <p>The mid-level way to create a segment is to take the payload data and call a
* static factory function such as {@link QrSegment#makeNumeric(String)}. The low-level
* static factory function such as {@link MakeNumericToSegment#makeNumericToSegment(String)}. The low-level
* way to create a segment is to custom-make the bit buffer and call the {@link
* QrSegment#QrSegment(Mode,int,BitBuffer) constructor} with appropriate values.</p>
* <p>This segment class imposes no length restrictions, but QR Codes have restrictions.
@ -49,6 +47,51 @@ public final class QrSegment {
/*---- Static factory functions (mid level) ----*/
/**
* Returns a segment representing the specified binary data
* encoded in byte mode. All input byte arrays are acceptable.
* <p>Any text string can be converted to UTF-8 bytes ({@code
* s.getBytes(StandardCharsets.UTF_8)}) and encoded as a byte mode segment.</p>
* @param data the binary data (not {@code null})
* @return a segment (not {@code null}) containing the data
* @throws NullPointerException if the array is {@code null}
*/
public static QrSegment makeBytes(byte[] data) {
MakeBytesToSegment makeBytesToSegment = new MakeBytesToSegment();
return makeBytesToSegment.excuteForBytedata(data);
}
/**
* Returns a segment representing the specified string of decimal digits encoded in numeric mode.
* @param digits the text (not {@code null}), with only digits from 0 to 9 allowed
* @return a segment (not {@code null}) containing the text
* @throws NullPointerException if the string is {@code null}
* @throws IllegalArgumentException if the string contains non-digit characters
*/
public static QrSegment makeNumeric(String digits) {
MakeSegment makeSegment = new MakeNumericToSegment();
return makeSegment.excute(digits);
}
/**
* 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 the text (not {@code null}), with only certain characters allowed
* @return a segment (not {@code null}) containing the text
* @throws NullPointerException if the string is {@code null}
* @throws IllegalArgumentException if the string contains non-encodable characters
*/
public static QrSegment makeAlphanumeric(String text) {
MakeSegment makeSegment = new MakeAlphaNumericToSegment();
return makeSegment.excute(text);
}
/**
* Returns a list of zero or more segments to represent the specified Unicode text string.
* The result may use various segment modes and switch modes to optimize the length of the bit stream.
@ -56,21 +99,6 @@ public final class QrSegment {
* @return a new mutable list (not {@code null}) of segments (not {@code null}) containing the text
* @throws NullPointerException if the text is {@code null}
*/
public static List<QrSegment> makeSegments(String text) {
Objects.requireNonNull(text);
// Select the most efficient segment encoding automatically
List<QrSegment> segments = new ArrayList<>();
if (text.equals("")); // Leave result empty
else if (NUMERIC_REGEX.matcher(text).matches())
segments.add(makeNumeric(text));
else if (ALPHANUMERIC_REGEX.matcher(text).matches())
segments.add(makeAlphanumeric(text));
else
segments.add(makeBytes(text.getBytes(StandardCharsets.UTF_8)));
return segments;
}
public static List<QrSegment> makeSegments(String text) {
Objects.requireNonNull(text);
// Select the most efficient segment encoding automatically
@ -82,10 +110,12 @@ public final class QrSegment {
return segments;
}
/**
* Returns a segment representing an Extended Channel Interpretation
* (ECI) designator with the specified assignment value.
* @param assignVal the ECI assignment number (see the AIM ECI specification)
* @param assignValue the ECI assignment number (see the AIM ECI specification)
* @return a segment (not {@code null}) containing the data
* @throws IllegalArgumentException if the value is outside the range [0, 10<sup>6</sup>)
*/
@ -116,7 +146,7 @@ public final class QrSegment {
/** The length of this segment's unencoded data. Measured in characters for
* numeric/alphanumeric/kanji mode, bytes for byte mode, and 0 for ECI mode.
* Always zero or positive. Not the same as the data's bit length. */
public final int numChars;
public final int numberOfCharacters;
// The data bits of this segment. Not null. Accessed through getData().
final BitBuffer data;
@ -128,8 +158,8 @@ public final class QrSegment {
* Constructs a QR Code segment with the specified attributes and data.
* The character count (numCh) must agree with the mode and the bit buffer length,
* but the constraint isn't checked. The specified bit buffer is cloned and stored.
* @param md the mode (not {@code null})
* @param numCh the data length in characters or bytes, which is non-negative
* @param _mode the mode (not {@code null})
* @param _numberOfCharacters the data length in characters or bytes, which is non-negative
* @param data the data bits (not {@code null})
* @throws NullPointerException if the mode or data is {@code null}
* @throws IllegalArgumentException if the character count is negative
@ -143,6 +173,7 @@ public final class QrSegment {
this.data = data.clone(); // Make defensive copy
}
/*---- Methods ----*/
/**
@ -157,49 +188,45 @@ public final class QrSegment {
// Calculates the number of bits needed to encode the given segments at the given version.
// Returns a non-negative number if successful. Otherwise returns -1 if a segment has too
// many characters to fit its length field, or the total bits exceeds Integer.MAX_VALUE.
static int getTotalBits(List<QrSegment> segs, int version) {
Objects.requireNonNull(segs);
long result = 0;
for (QrSegment seg : segs) {
Objects.requireNonNull(seg);
int ccbits = seg.mode.numCharCountBits(version);
if (seg.numChars >= (1 << ccbits))
return -1; // The segment's length doesn't fit the field's bit width
result += 4L + ccbits + seg.data.bitLength();
if (result > Integer.MAX_VALUE)
return -1; // The sum will overflow an int type
}
return (int)result;
}
static int getTotalBits(List<QrSegment> segments, int version) {
Objects.requireNonNull(segments);
long TotalBits = 0;
for (QrSegment segment : segments) {
Objects.requireNonNull(segment);
int characterCountBits = segment.mode.numCharCountBits(version);
if (segment.numberOfCharacters >= (1 << characterCountBits))
if (DoesNotSegmentLengthFitTheFieldBitWidth(segment, characterCountBits))
return -1; // The segment's length doesn't fit the field's bit width
TotalBits += 4L + characterCountBits + segment.data.bitLength();
if (TotalBits > Integer.MAX_VALUE)
if (IsTotalBitsOutOfIntegerRange(TotalBits))
return -1; // The sum will overflow an int type
}
return (int)TotalBits;
}
public static boolean IsTotalBitsOutOfIntegerRange(long result) {
return result > Integer.MAX_VALUE;
}
public static boolean DoesNotSegmentLengthFitTheFieldBitWidth(QrSegment segment, int characterCountBits) {
return segment.numberOfCharacters >= (1 << characterCountBits);
}
/*---- Constants ----*/
/** Describes precisely all strings that are encodable in numeric mode. To test whether a
* string {@code s} is encodable: {@code boolean ok = NUMERIC_REGEX.matcher(s).matches();}.
* A string is encodable iff each character is in the range 0 to 9.
* @see #makeNumeric(String) */
* @see MakeNumericToSegment#makeNumericToSegment(String) */
public static final Pattern NUMERIC_REGEX = Pattern.compile("[0-9]*");
/** Describes precisely all strings that are encodable in alphanumeric mode. To test whether a
* string {@code s} is encodable: {@code boolean ok = ALPHANUMERIC_REGEX.matcher(s).matches();}.
* A string is encodable iff each character is in the following set: 0 to 9, A to Z
* (uppercase only), space, dollar, percent, asterisk, plus, hyphen, period, slash, colon.
* @see #makeAlphanumeric(String) */
* @see MakeAlphaNumericToSegment#makeAlphaNumericToSegment(String) */
public static final Pattern ALPHANUMERIC_REGEX = Pattern.compile("[A-Z0-9 $%*+./:-]*");
// The set of all legal characters in alphanumeric mode, where

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