core-java-modules/core-java-uuid/src/main/resources/log4jstructuraldp.properties

@@ -0,0 +1,9 @@
+
+# Root logger 
+log4j.rootLogger=INFO, file, stdout
+
+# Write to console
+log4j.appender.stdout=org.apache.log4j.ConsoleAppender
+log4j.appender.stdout.Target=System.out
+log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
+log4j.appender.stdout.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n

core-java-modules/core-java-uuid/src/main/resources/logback.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
+            </pattern>
+        </encoder>
+    </appender>
+
+    <logger name="org.springframework" level="WARN" />
+    <logger name="org.springframework.transaction" level="WARN" />
+
+    <!-- in order to debug some marshalling issues, this needs to be TRACE -->
+    <logger name="org.springframework.web.servlet.mvc" level="WARN" />
+
+    <root level="INFO">
+        <appender-ref ref="STDOUT" />
+    </root>
+</configuration>

core-java-modules/core-java-uuid/src/test/java/com/ossez/uuid/DecodeUUIDStringFromBase64UnitTest.java

@@ -0,0 +1,64 @@
+package com.ossez.uuid;
+
+import static org.apache.commons.codec.binary.Base64.decodeBase64;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.nio.ByteBuffer;
+import java.util.Base64;
+import java.util.UUID;
+
+import org.apache.commons.lang3.Conversion;
+import org.junit.jupiter.api.Test;
+
+public class DecodeUUIDStringFromBase64UnitTest {
+    private final UUID originalUUID = UUID.fromString("cc5f93f7-8cf1-4a51-83c6-e740313a0c6c");
+
+    @Test
+    public void givenEncodedString_whenDecodingUsingBase64Decoder_thenGiveExpectedUUID() {
+        String expectedEncodedString = "UUrxjPeTX8xsDDoxQOfGgw";
+        byte[] decodedBytes = Base64.getDecoder()
+          .decode(expectedEncodedString);
+        UUID uuid = convertToUUID(decodedBytes);
+        assertEquals(originalUUID, uuid);
+    }
+
+    @Test
+    public void givenEncodedString_whenDecodingUsingByteBufferAndBase64UrlDecoder_thenGiveExpectedUUID() {
+        String expectedEncodedString = "zF-T94zxSlGDxudAMToMbA";
+        byte[] decodedBytes = Base64.getUrlDecoder()
+          .decode(expectedEncodedString);
+        ByteBuffer byteBuffer = ByteBuffer.wrap(decodedBytes);
+        long mostSignificantBits = byteBuffer.getLong();
+        long leastSignificantBits = byteBuffer.getLong();
+        UUID uuid = new UUID(mostSignificantBits, leastSignificantBits);
+        assertEquals(originalUUID, uuid);
+    }
+
+    @Test
+    public void givenEncodedString_whenDecodingUsingApacheUtils_thenGiveExpectedUUID() {
+        String expectedEncodedString = "UUrxjPeTX8xsDDoxQOfGgw";
+        byte[] decodedBytes = decodeBase64(expectedEncodedString);
+        UUID uuid = Conversion.byteArrayToUuid(decodedBytes, 0);
+        assertEquals(originalUUID, uuid);
+    }
+
+    private UUID convertToUUID(byte[] src) {
+        long mostSignificantBits = convertBytesToLong(src, 0);
+        long leastSignificantBits = convertBytesToLong(src, 8);
+
+        return new UUID(mostSignificantBits, leastSignificantBits);
+    }
+
+    private long convertBytesToLong(byte[] uuidBytes, int start) {
+        long result = 0;
+
+        for(int i = 0; i < 8; i++) {
+            int shift = i * 8;
+            long bits = (255L & (long)uuidBytes[i + start]) << shift;
+            long mask = 255L << shift;
+            result = result & ~mask | bits;
+        }
+
+        return result;
+    }
+}

core-java-modules/core-java-uuid/src/test/java/com/ossez/uuid/EncodeUUIDToBase64StringUnitTest.java

@@ -0,0 +1,62 @@
+package com.ossez.uuid;
+
+import static org.apache.commons.codec.binary.Base64.encodeBase64URLSafeString;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.nio.ByteBuffer;
+import java.util.Base64;
+import java.util.UUID;
+
+import org.apache.commons.lang3.Conversion;
+import org.junit.jupiter.api.Test;
+
+public class EncodeUUIDToBase64StringUnitTest {
+    private final UUID originalUUID = UUID.fromString("cc5f93f7-8cf1-4a51-83c6-e740313a0c6c");
+
+    @Test
+    public void givenUUID_whenEncodingUsingBase64Encoder_thenGiveExpectedEncodedString() {
+        String expectedEncodedString = "UUrxjPeTX8xsDDoxQOfGgw";
+        byte[] uuidBytes = convertToByteArray(originalUUID);
+        String encodedUUID = Base64.getEncoder().withoutPadding()
+          .encodeToString(uuidBytes);
+        assertEquals(expectedEncodedString, encodedUUID);
+    }
+
+    @Test
+    public void givenUUID_whenEncodingUsingByteBufferAndBase64UrlEncoder_thenGiveExpectedEncodedString() {
+        String expectedEncodedString = "zF-T94zxSlGDxudAMToMbA";
+        ByteBuffer byteBuffer = ByteBuffer.wrap(new byte[16]);
+        byteBuffer.putLong(originalUUID.getMostSignificantBits());
+        byteBuffer.putLong(originalUUID.getLeastSignificantBits());
+        String encodedUUID = Base64.getUrlEncoder().withoutPadding()
+          .encodeToString(byteBuffer.array());
+        assertEquals(expectedEncodedString, encodedUUID);
+    }
+
+    @Test
+    public void givenUUID_whenEncodingUsingApacheUtils_thenGiveExpectedEncodedString() {
+        String expectedEncodedString = "UUrxjPeTX8xsDDoxQOfGgw";
+        byte[] bytes = Conversion.uuidToByteArray(originalUUID, new byte[16], 0, 16);
+        String encodedUUID = encodeBase64URLSafeString(bytes);
+        assertEquals(expectedEncodedString, encodedUUID);
+    }
+
+    private byte[] convertToByteArray(UUID uuid) {
+        byte[] result = new byte[16];
+
+        long mostSignificantBits = uuid.getMostSignificantBits();
+        fillByteArray(0, 8, result, mostSignificantBits);
+
+        long leastSignificantBits = uuid.getLeastSignificantBits();
+        fillByteArray(8, 16, result, leastSignificantBits);
+
+        return result;
+    }
+
+    private static void fillByteArray(int start, int end, byte[] result, long bits) {
+        for (int i = start; i < end; i++) {
+            int shift = i * 8;
+            result[i] = (byte) ((int) (255L & bits >> shift));
+        }
+    }
+}

core-java-modules/core-java-uuid/src/test/java/com/ossez/uuid/UUIDPositiveLongGeneratorUnitTest.java

@@ -0,0 +1,22 @@
+package com.ossez.uuid;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.UUID;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class UUIDPositiveLongGeneratorUnitTest {
+
+    @Test
+    public void whenGetMostSignificantBits_thenAssertPositive() {
+        long randomPositiveLong = Math.abs(UUID.randomUUID().getMostSignificantBits());
+        assertThat(randomPositiveLong).isNotNegative();
+    }
+
+    @Test
+    public void whenGetLeastSignificantBits_thenAssertPositive() {
+        long randomPositiveLong = Math.abs(UUID.randomUUID().getLeastSignificantBits());
+        assertThat(randomPositiveLong).isNotNegative();
+    }
+}

core-java-modules/core-java-uuid/src/test/resources/logback.xml

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
+        </encoder>
+    </appender>
+
+    <logger name="org.springframework" level="WARN" />
+    <logger name="org.springframework.transaction" level="WARN" />
+
+    <!-- in order to debug some marshalling issues, this needs to be TRACE -->
+    <logger name="org.springframework.web.servlet.mvc" level="WARN" />
+
+    <root level="INFO">
+        <appender-ref ref="STDOUT" />
+    </root>
+</configuration>