diff --git a/java/io/nayuki/qrcodegen/BitBuffer.java b/java/io/nayuki/qrcodegen/BitBuffer.java
index e759aeb..d918570 100644
--- a/java/io/nayuki/qrcodegen/BitBuffer.java
+++ b/java/io/nayuki/qrcodegen/BitBuffer.java
@@ -25,6 +25,7 @@
 package io.nayuki.qrcodegen;
 
 import java.util.Arrays;
+import java.util.Objects;
 
 
 /**
@@ -76,8 +77,7 @@ final class BitBuffer {
 	
 	// Appends the data of the given segment to this bit buffer.
 	public void appendData(QrSegment seg) {
-		if (seg == null)
-			throw new NullPointerException();
+		Objects.requireNonNull(seg);
 		ensureCapacity(bitLength + seg.bitLength);
 		for (int i = 0; i < seg.bitLength; i++, bitLength++) {  // Append bit by bit
 			int bit = (seg.getByte(i >>> 3) >>> (7 - (i & 7))) & 1;
diff --git a/java/io/nayuki/qrcodegen/QrCode.java b/java/io/nayuki/qrcodegen/QrCode.java
index 669c09e..69bf1ee 100644
--- a/java/io/nayuki/qrcodegen/QrCode.java
+++ b/java/io/nayuki/qrcodegen/QrCode.java
@@ -27,6 +27,7 @@ package io.nayuki.qrcodegen;
 import java.awt.image.BufferedImage;
 import java.util.Arrays;
 import java.util.List;
+import java.util.Objects;
 
 
 /**
@@ -51,8 +52,8 @@ public final class QrCode {
 	 * @throws IllegalArgumentException if the text fails to fit in the largest version QR Code, which means it is too long
 	 */
 	public static QrCode encodeText(String text, Ecc ecl) {
-		if (text == null || ecl == null)
-			throw new NullPointerException();
+		Objects.requireNonNull(text);
+		Objects.requireNonNull(ecl);
 		List<QrSegment> segs = QrSegment.makeSegments(text);
 		return encodeSegments(segs, ecl);
 	}
@@ -70,8 +71,8 @@ public final class QrCode {
 	 * @throws IllegalArgumentException if the data fails to fit in the largest version QR Code, which means it is too long
 	 */
 	public static QrCode encodeBinary(byte[] data, Ecc ecl) {
-		if (data == null || ecl == null)
-			throw new NullPointerException();
+		Objects.requireNonNull(data);
+		Objects.requireNonNull(ecl);
 		QrSegment seg = QrSegment.makeBytes(data);
 		return encodeSegments(Arrays.asList(seg), ecl);
 	}
@@ -112,8 +113,8 @@ public final class QrCode {
 	 * &lt; &minus;1 or mask > 7, or if the data is too long to fit in a QR Code at maxVersion at the ECL
 	 */
 	public static QrCode encodeSegments(List<QrSegment> segs, Ecc ecl, int minVersion, int maxVersion, int mask, boolean boostEcl) {
-		if (segs == null || ecl == null)
-			throw new NullPointerException();
+		Objects.requireNonNull(segs);
+		Objects.requireNonNull(ecl);
 		if (!(1 <= minVersion && minVersion <= maxVersion && maxVersion <= 40) || mask < -1 || mask > 7)
 			throw new IllegalArgumentException("Invalid value");
 		
@@ -201,12 +202,10 @@ public final class QrCode {
 	 */
 	public QrCode(int ver, Ecc ecl, byte[] dataCodewords, int mask) {
 		// Check arguments
-		if (ecl == null)
-			throw new NullPointerException();
+		Objects.requireNonNull(ecl);
 		if (ver < 1 || ver > 40 || mask < -1 || mask > 7)
 			throw new IllegalArgumentException("Value out of range");
-		if (dataCodewords == null)
-			throw new NullPointerException();
+		Objects.requireNonNull(dataCodewords);
 		
 		// Initialize fields
 		version = ver;
@@ -234,8 +233,7 @@ public final class QrCode {
 	 */
 	public QrCode(QrCode qr, int mask) {
 		// Check arguments
-		if (qr == null)
-			throw new NullPointerException();
+		Objects.requireNonNull(qr);
 		if (mask < -1 || mask > 7)
 			throw new IllegalArgumentException("Mask value out of range");
 		
@@ -497,8 +495,7 @@ public final class QrCode {
 	// Draws the given sequence of 8-bit codewords (data and error correction) onto the entire
 	// data area of this QR Code symbol. Function modules need to be marked off before this is called.
 	private void drawCodewords(byte[] data) {
-		if (data == null)
-			throw new NullPointerException();
+		Objects.requireNonNull(data);
 		if (data.length != getNumRawDataModules(version) / 8)
 			throw new IllegalArgumentException();
 		
@@ -832,8 +829,7 @@ public final class QrCode {
 		 * @throws NullPointerException if the data is {@code null}
 		 */
 		public byte[] getRemainder(byte[] data) {
-			if (data == null)
-				throw new NullPointerException();
+			Objects.requireNonNull(data);
 			
 			// Compute the remainder by performing polynomial division
 			byte[] result = new byte[coefficients.length];
diff --git a/java/io/nayuki/qrcodegen/QrSegment.java b/java/io/nayuki/qrcodegen/QrSegment.java
index 35ce18e..b7abb7c 100644
--- a/java/io/nayuki/qrcodegen/QrSegment.java
+++ b/java/io/nayuki/qrcodegen/QrSegment.java
@@ -28,6 +28,7 @@ import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
+import java.util.Objects;
 import java.util.regex.Pattern;
 
 
@@ -50,8 +51,7 @@ public final class QrSegment {
 	 * @throws NullPointerException if the array is {@code null}
 	 */
 	public static QrSegment makeBytes(byte[] data) {
-		if (data == null)
-			throw new NullPointerException();
+		Objects.requireNonNull(data);
 		return new QrSegment(Mode.BYTE, data.length, data, data.length * 8);
 	}
 	
@@ -64,8 +64,7 @@ public final class QrSegment {
 	 * @throws IllegalArgumentException if the string contains non-digit characters
 	 */
 	public static QrSegment makeNumeric(String digits) {
-		if (digits == null)
-			throw new NullPointerException();
+		Objects.requireNonNull(digits);
 		if (!NUMERIC_REGEX.matcher(digits).matches())
 			throw new IllegalArgumentException("String contains non-numeric characters");
 		
@@ -89,8 +88,7 @@ public final class QrSegment {
 	 * @throws IllegalArgumentException if the string contains non-encodable characters
 	 */
 	public static QrSegment makeAlphanumeric(String text) {
-		if (text == null)
-			throw new NullPointerException();
+		Objects.requireNonNull(text);
 		if (!ALPHANUMERIC_REGEX.matcher(text).matches())
 			throw new IllegalArgumentException("String contains unencodable characters in alphanumeric mode");
 		
@@ -115,8 +113,7 @@ public final class QrSegment {
 	 * @throws NullPointerException if the text is {@code null}
 	 */
 	public static List<QrSegment> makeSegments(String text) {
-		if (text == null)
-			throw new NullPointerException();
+		Objects.requireNonNull(text);
 		
 		// Select the most efficient segment encoding automatically
 		List<QrSegment> result = new ArrayList<>();
@@ -160,8 +157,8 @@ public final class QrSegment {
 	 * @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();
+		Objects.requireNonNull(md);
+		Objects.requireNonNull(b);
 		if (numCh < 0 || bitLen < 0 || bitLen > b.length * 8L)
 			throw new IllegalArgumentException("Invalid value");
 		mode = md;
@@ -188,15 +185,13 @@ public final class QrSegment {
 	
 	// Package-private helper function.
 	static int getTotalBits(List<QrSegment> segs, int version) {
-		if (segs == null)
-			throw new NullPointerException();
+		Objects.requireNonNull(segs);
 		if (version < 1 || version > 40)
 			throw new IllegalArgumentException("Version number out of range");
 		
 		int result = 0;
 		for (QrSegment seg : segs) {
-			if (seg == null)
-				throw new NullPointerException();
+			Objects.requireNonNull(seg);
 			int ccbits = seg.mode.numCharCountBits(version);
 			// Fail if segment length value doesn't fit in the length field's bit-width
 			if (seg.numChars >= (1 << ccbits))
diff --git a/java/io/nayuki/qrcodegen/QrSegmentAdvanced.java b/java/io/nayuki/qrcodegen/QrSegmentAdvanced.java
index fe7be0e..ef813bd 100644
--- a/java/io/nayuki/qrcodegen/QrSegmentAdvanced.java
+++ b/java/io/nayuki/qrcodegen/QrSegmentAdvanced.java
@@ -32,6 +32,7 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Base64;
 import java.util.List;
+import java.util.Objects;
 
 
 public final class QrSegmentAdvanced {
@@ -57,8 +58,8 @@ public final class QrSegmentAdvanced {
 	 */
 	public static List<QrSegment> makeSegmentsOptimally(String text, QrCode.Ecc ecl, int minVersion, int maxVersion) {
 		// Check arguments
-		if (text == null || ecl == null)
-			throw new NullPointerException();
+		Objects.requireNonNull(text);
+		Objects.requireNonNull(ecl);
 		if (!(1 <= minVersion && minVersion <= maxVersion && maxVersion <= 40))
 			throw new IllegalArgumentException("Invalid value");
 		
@@ -238,8 +239,7 @@ public final class QrSegmentAdvanced {
 	 * @see #isEncodableAsKanji(String)
 	 */
 	public static QrSegment makeKanjiSegment(String text) {
-		if (text == null)
-			throw new NullPointerException();
+		Objects.requireNonNull(text);
 		BitBuffer bb = new BitBuffer();
 		for (int i = 0; i < text.length(); i++) {
 			int val = UNICODE_TO_QR_KANJI[text.charAt(i)];
@@ -262,8 +262,7 @@ public final class QrSegmentAdvanced {
 	 * @see #makeKanjiSegment(String)
 	 */
 	public static boolean isEncodableAsKanji(String text) {
-		if (text == null)
-			throw new NullPointerException();
+		Objects.requireNonNull(text);
 		for (int i = 0; i < text.length(); i++) {
 			if (UNICODE_TO_QR_KANJI[text.charAt(i)] == -1)
 				return false;