1.Strategy Pattern

2. AlphanumericMode, ByteMode, EciMode, NumericMode, QrMode
3. Add java class for using Strategy Pattern

java/src/main/java/io/nayuki/qrcodegen/AlphanumericMode.java

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+package io.nayuki.qrcodegen;
+
+import java.nio.charset.StandardCharsets;
+
+public class AlphanumericMode extends QrMode {
+	protected AlphanumericMode(int mode, int... ccbits) {
+		modeBits = mode;
+		numBitsCharCount = ccbits;
+	}
+	
+	protected AlphanumericMode() {
+		modeBits = 0x2;
+		numBitsCharCount[0] = 9;
+		numBitsCharCount[1] = 11;
+		numBitsCharCount[2] = 13;
+	}
+	
+	public int getcost(int pre, int codePoint) {
+		return pre + 33;
+	}
+	
+	public QrSegment making(String str) {
+		return QrSegment.makeAlphanumeric(str);
+	}
+}

java/src/main/java/io/nayuki/qrcodegen/ByteMode.java

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+package io.nayuki.qrcodegen;
+
+import java.nio.charset.StandardCharsets;
+
+public class ByteMode extends QrMode {
+	protected ByteMode(int mode, int... ccbits) {
+		modeBits = mode;
+		numBitsCharCount = ccbits;
+	}
+	
+	protected ByteMode() {
+		modeBits = 0x4;
+		numBitsCharCount[0] = 8;
+		numBitsCharCount[1] = 16;
+		numBitsCharCount[2] = 16;
+	}
+	
+	public int getcost(int pre, int codePoint) {
+		return pre + QrSegmentAdvanced.countUtf8Bytes(codePoint) * 8 * 6;
+	}
+	
+	public QrSegment making(String str) {
+		return QrSegment.makeBytes(str.getBytes(StandardCharsets.UTF_8));
+	}
+}

java/src/main/java/io/nayuki/qrcodegen/EciMode.java

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+package io.nayuki.qrcodegen;
+
+public class EciMode extends QrMode {
+	protected EciMode(int mode, int... ccbits) {
+		modeBits = mode;
+		numBitsCharCount = ccbits;
+	}
+	
+	protected EciMode() {
+		modeBits = 0x7;
+		numBitsCharCount[0] = 0;
+		numBitsCharCount[1] = 0;
+		numBitsCharCount[2] = 0;
+	}
+	
+	public QrSegment making(int prmt) {
+		return QrSegment.makeEci(prmt);
+	}
+	
+	public int getcost(int pre, int codePoint) {
+		return pre;
+	}
+}

java/src/main/java/io/nayuki/qrcodegen/NumericMode.java

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+package io.nayuki.qrcodegen;
+
+public class NumericMode extends QrMode {
+	protected NumericMode(int mode, int... ccbits) {
+		modeBits = mode;
+		numBitsCharCount = ccbits;
+	}
+	
+	protected NumericMode() {
+		modeBits = 0x1;
+		numBitsCharCount[0] = 10;
+		numBitsCharCount[1] = 12;
+		numBitsCharCount[2] = 1;
+	}
+	
+	public int getcost(int pre, int codePoint) {
+		return pre + 20;
+	}
+	
+	public QrSegment making(String str) {
+		return QrSegment.makeNumeric(str);
+	}
+}

java/src/main/java/io/nayuki/qrcodegen/QrMode.java

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+package io.nayuki.qrcodegen;
+
+public abstract class QrMode {
+	/*-- Fields --*/
+	
+	// The mode indicator bits, which is a uint4 value (range 0 to 15).
+	int modeBits;
+	
+	// Number of character count bits for three different version ranges.
+	protected int[] numBitsCharCount;
+	
+	int headCost;
+	/*-- Method --*/
+	
+	// Returns the bit width of the character count field for a segment in this mode
+	// in a QR Code at the given version number. The result is in the range [0, 16].
+	int numCharCountBits(int ver) {
+		assert QrCode.MIN_VERSION <= ver && ver <= QrCode.MAX_VERSION;
+		return numBitsCharCount[(ver + 7) / 17];
+	}
+	
+	protected QrMode() {
+		this.modeBits = 0;
+		this.numBitsCharCount = null;
+	}
+	
+	public void get(QrMode md) {
+		this.modeBits = md.modeBits;
+		this.numBitsCharCount = md.numBitsCharCount;
+	}
+	
+	public int whichMode() {
+		return modeBits;
+	}
+
+	protected QrSegment making(String s) {
+		return null;
+	}
+	
+	public int getcost(int pre, int codePoint) {
+		return pre;
+	}
+}