Use HexFormat for converting from bytes to hex string and the other way round

src/main/java/client/command/commands/gm3/PeCommand.java

@@ -64,7 +64,7 @@ public class PeCommand extends Command {
 
         }
 
-        byte[] packetContent = HexTool.getByteArrayFromHexString(packet);
+        byte[] packetContent = HexTool.toBytes(packet);
         InPacket inPacket = new ByteBufInPacket(Unpooled.wrappedBuffer(packetContent));
         short packetId = inPacket.readShort();
         final PacketHandler packetHandler = PacketProcessor.getProcessor(0, c.getChannel()).getHandler(packetId);

src/main/java/tools/HexTool.java

@@ -24,26 +24,21 @@ package tools;
 import constants.string.CharsetConstants;
 import io.netty.buffer.ByteBufUtil;
 
-import java.io.ByteArrayOutputStream;
 import java.util.HexFormat;
 
 // TODO: use HexFormat from Java 17
 public class HexTool {
-    private static final char[] HEX = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
-
-    private static String toString(byte byteValue) {
-        int tmp = byteValue << 8;
-        char[] retstr = new char[]{HEX[(tmp >> 12) & 0x0F], HEX[(tmp >> 8) & 0x0F]};
-        return String.valueOf(retstr);
-    }
 
+    /**
+     * Convert a byte array to its hex string representation.
+     * Each byte value is equivalent to two hex characters delimited by a space.
+     *
+     * @param bytes Byte array to convert to a hex string.
+     *              Example: {1, 16, 127, -1} is converted to "01 F0 7F FF"
+     * @return The hex string
+     */
     public static String toString(byte[] bytes) {
-        StringBuilder hexed = new StringBuilder();
-        for (byte aByte : bytes) {
-            hexed.append(toString(aByte));
-            hexed.append(' ');
-        }
-        return hexed.substring(0, hexed.length() - 1);
+        return HexFormat.ofDelimiter(" ").withUpperCase().formatHex(bytes);
     }
 
     /**
@@ -61,43 +56,6 @@ public class HexTool {
         return input.replaceAll("\\s", "");
     }
 
-    public static byte[] getByteArrayFromHexString(String hex) {
-        ByteArrayOutputStream baos = new ByteArrayOutputStream();
-        int nexti = 0;
-        int nextb = 0;
-        boolean highoc = true;
-        outer:
-        for (; ; ) {
-            int number = -1;
-            while (number == -1) {
-                if (nexti == hex.length()) {
-                    break outer;
-                }
-                char chr = hex.charAt(nexti);
-                if (chr >= '0' && chr <= '9') {
-                    number = chr - '0';
-                } else if (chr >= 'a' && chr <= 'f') {
-                    number = chr - 'a' + 10;
-                } else if (chr >= 'A' && chr <= 'F') {
-                    number = chr - 'A' + 10;
-                } else {
-                    number = -1;
-                }
-                nexti++;
-            }
-            if (highoc) {
-                nextb = number << 4;
-                highoc = false;
-            } else {
-                nextb |= number;
-                highoc = true;
-                baos.write(nextb);
-            }
-        }
-        // return toBytes(hex);
-        return baos.toByteArray();
-    }
-
     public static String toStringFromAscii(final byte[] bytes) {
         byte[] ret = new byte[bytes.length];
         for (int x = 0; x < bytes.length; x++) {

src/main/java/tools/PacketCreator.java

@@ -3307,7 +3307,7 @@ public class PacketCreator {
         p.writeByte(msgType);
         p.writeByte(speaker);
         p.writeString(talk);
-        p.writeBytes(HexTool.getByteArrayFromHexString(endBytes));
+        p.writeBytes(HexTool.toBytes(endBytes));
         return p;
     }
 
@@ -6887,7 +6887,7 @@ public class PacketCreator {
 
     public static Packet customPacket(String packet) {
         OutPacket p = new ByteBufOutPacket();
-        p.writeBytes(HexTool.getByteArrayFromHexString(packet));
+        p.writeBytes(HexTool.toBytes(packet));
         return p;
     }
 

src/test/java/tools/HexToolTest.java

@@ -1,10 +1,7 @@
 package tools;
 
-import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
 
-import java.util.Arrays;
-
 import static org.junit.jupiter.api.Assertions.assertArrayEquals;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
@@ -21,23 +18,14 @@ class HexToolTest {
     void hexStringWithSpacesToBytes() {
         String hexString = "01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F 10 11 7F FF";
         byte[] expectedBytes = new byte[]{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 127, -1};
-        assertArrayEquals(expectedBytes, HexTool.getByteArrayFromHexString(hexString));
+        assertArrayEquals(expectedBytes, HexTool.toBytes(hexString));
     }
 
     @Test
     void compactHexStringToBytes() {
         String hexString = "0102030405060708090A0B0C0D0E0F10117FFF";
         byte[] expectedBytes = new byte[]{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 127, -1};
-        assertArrayEquals(expectedBytes, HexTool.getByteArrayFromHexString(hexString));
-    }
-
-    @Test
-    @Disabled("The original method does not work this way, this test should be removed!")
-    void compactShortHexStringToBytes() {
-        String hexString = "0 2 3 4 5 A F";
-        byte[] expectedBytes = new byte[]{1, 2, 3, 4, 5, 10, 15};
-        System.out.println(Arrays.toString(HexTool.getByteArrayFromHexString(hexString)));
-        assertArrayEquals(expectedBytes, HexTool.getByteArrayFromHexString(hexString));
+        assertArrayEquals(expectedBytes, HexTool.toBytes(hexString));
     }
 
     @Test