From a567d3187141f582d891442bb09ec935ec1dcfcd Mon Sep 17 00:00:00 2001 From: "@hangga" Date: Tue, 31 Oct 2023 18:15:47 +0700 Subject: [PATCH 01/24] add some methods --- .../com/baeldung/uuid/UUIDLongGenerator.java | 58 +++++++++++++++++++ 1 file changed, 58 insertions(+) create mode 100644 core-java-modules/core-java-uuid/src/main/java/com/baeldung/uuid/UUIDLongGenerator.java diff --git a/core-java-modules/core-java-uuid/src/main/java/com/baeldung/uuid/UUIDLongGenerator.java b/core-java-modules/core-java-uuid/src/main/java/com/baeldung/uuid/UUIDLongGenerator.java new file mode 100644 index 0000000000..8ac71b1ce6 --- /dev/null +++ b/core-java-modules/core-java-uuid/src/main/java/com/baeldung/uuid/UUIDLongGenerator.java @@ -0,0 +1,58 @@ +package com.baeldung.uuid; + +import java.nio.ByteBuffer; +import java.util.UUID; + +public class UUIDLongGenerator { + public long getLeastSignificantBits(){ + return UUID.randomUUID().getLeastSignificantBits(); + } + + public long getMostSignificantBits(){ + return UUID.randomUUID().getMostSignificantBits(); + } + + public long gethashCode(){ + return UUID.randomUUID().toString().hashCode(); + } + + public long combineByteBuffer(){ + UUID uuid = UUID.randomUUID(); + ByteBuffer bb = ByteBuffer.wrap(new byte[16]); + bb.putLong(uuid.getMostSignificantBits()); + bb.putLong(uuid.getLeastSignificantBits()); + bb.rewind(); // Kembalikan posisi buffer ke awal + return bb.getLong(); + } + + public long combineBitwise(){ + UUID uniqueUUID; + uniqueUUID = UUID.randomUUID(); + return (uniqueUUID.getMostSignificantBits() << 32) | (uniqueUUID.getLeastSignificantBits() & 0xFFFFFFFFL); + } + + public long combineDirect(){ + UUID uniqueUUID = UUID.randomUUID(); + long mostSignificantBits = uniqueUUID.getMostSignificantBits(); + long leastSignificantBits = uniqueUUID.getLeastSignificantBits(); + return mostSignificantBits ^ (leastSignificantBits >> 1); + } + + public long combinePermutation(){ + UUID uuid = UUID.randomUUID(); + long mostSigBits = uuid.getMostSignificantBits(); + long leastSigBits = uuid.getLeastSignificantBits(); + byte[] uuidBytes = new byte[16]; + + for (int i = 0; i < 8; i++) { + uuidBytes[i] = (byte) (mostSigBits >>> (8 * (7 - i))); + uuidBytes[i + 8] = (byte) (leastSigBits >>> (8 * (7 - i))); + } + + long result = 0; + for (byte b : uuidBytes) { + result = (result << 8) | (b & 0xFF); + } + return result; + } +} From ece5cdeb6ee96e85f29d556ed080f7ce13e8a2f8 Mon Sep 17 00:00:00 2001 From: "@hangga" Date: Tue, 31 Oct 2023 18:17:54 +0700 Subject: [PATCH 02/24] add unit test --- .../uuid/UUIDLongGeneratorUnitTest.java | 63 +++++++++++++++++++ 1 file changed, 63 insertions(+) create mode 100644 core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDLongGeneratorUnitTest.java diff --git a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDLongGeneratorUnitTest.java b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDLongGeneratorUnitTest.java new file mode 100644 index 0000000000..24add0a14a --- /dev/null +++ b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDLongGeneratorUnitTest.java @@ -0,0 +1,63 @@ +package com.baeldung.uuid; + +import org.junit.jupiter.api.Test; + +import java.lang.reflect.InvocationTargetException; +import java.lang.reflect.Method; +import java.text.DecimalFormat; +import java.util.HashSet; +import java.util.Set; +import java.util.concurrent.atomic.AtomicInteger; +import java.util.stream.IntStream; + +import static org.junit.jupiter.api.Assertions.assertTrue; + +public class UUIDLongGeneratorUnitTest { + final static int n = 1000000; + UUIDLongGenerator uuidLongGenerator = new UUIDLongGenerator(); + + @Test + void whenForeachGenerateLongValue_thenCollisionsCheck() { + printTableHeader(); + for (Method method : uuidLongGenerator.getClass().getDeclaredMethods()) { + collisionAndNegativeCheck(method); + } + } + + private void printTableHeader() { + System.out.format("%-30s %-15s %-15s %-15s %-15s%n", "Approach", "collisions", "negatives", "collision", "negative"); + System.out.format("%-30s %-15s %-15s %-15s %-15s%n", "(method name)", "count", "count", "probability", "probability"); + System.out.println("--------------------------------------------------------------------------------------------"); + } + + private void printOutput(String method, int collisionsCount, int negativeCount, double collisionsProbability, double negativeProbability) { + DecimalFormat decimalFormat = new DecimalFormat("#.#####"); + System.out.format("%-30s %-15s %-15s %-15s %-15s%n", method, collisionsCount, negativeCount, decimalFormat.format(collisionsProbability), decimalFormat.format(negativeProbability)); + } + + private void collisionAndNegativeCheck(Method method) { + Set uniqueValues = new HashSet<>(); + AtomicInteger collisions = new AtomicInteger(0); + AtomicInteger negative = new AtomicInteger(0); + + IntStream.range(0, n).forEach(i -> { + try { + long uniqueValue = (long) method.invoke(uuidLongGenerator); + if (!uniqueValues.add(uniqueValue)) { + collisions.incrementAndGet(); + } + if (uniqueValue < 0) { + negative.incrementAndGet(); + } + } catch (IllegalAccessException | InvocationTargetException e) { + throw new RuntimeException(e); + } + }); + + double collisionsProbability = (double) collisions.get() / n; + double negativeProbability = (double) negative.get() / n; + printOutput(method.getName(), collisions.get(), negative.get(), collisionsProbability, negativeProbability); + + assertTrue(collisionsProbability <= 0.001); // threshold = 0.001 + } +} From 016579337010ab145058a3b25dc8b437f8c6f1b6 Mon Sep 17 00:00:00 2001 From: Hangga Aji Sayekti Date: Wed, 1 Nov 2023 10:36:43 +0700 Subject: [PATCH 03/24] Update core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDLongGeneratorUnitTest.java IntStream to loop Co-authored-by: Liam Williams --- .../uuid/UUIDLongGeneratorUnitTest.java | 22 ++++++++----------- 1 file changed, 9 insertions(+), 13 deletions(-) diff --git a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDLongGeneratorUnitTest.java b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDLongGeneratorUnitTest.java index 24add0a14a..6d2dff959c 100644 --- a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDLongGeneratorUnitTest.java +++ b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDLongGeneratorUnitTest.java @@ -37,20 +37,16 @@ public class UUIDLongGeneratorUnitTest { private void collisionAndNegativeCheck(Method method) { Set uniqueValues = new HashSet<>(); - AtomicInteger collisions = new AtomicInteger(0); - AtomicInteger negative = new AtomicInteger(0); + int collisions = 0; + int negative = 0; - IntStream.range(0, n).forEach(i -> { - try { - long uniqueValue = (long) method.invoke(uuidLongGenerator); - if (!uniqueValues.add(uniqueValue)) { - collisions.incrementAndGet(); - } - if (uniqueValue < 0) { - negative.incrementAndGet(); - } - } catch (IllegalAccessException | InvocationTargetException e) { - throw new RuntimeException(e); + for (int i = 0; i < n; i++) { + long uniqueValue = (long) method.invoke(uuidLongGenerator); + if (!uniqueValues.add(uniqueValue)) { + collisions++; + } + if (uniqueValue < 0) { + negative++; } }); From b55db89b5fb10e1fb4d678505f86fe54a82b355c Mon Sep 17 00:00:00 2001 From: "@hangga" Date: Wed, 1 Nov 2023 10:37:14 +0700 Subject: [PATCH 04/24] update --- ...or.java => UUIDPositiveLongGenerator.java} | 22 ++++--- .../uuid/UUIDLongGeneratorUnitTest.java | 63 ------------------- .../UUIDPositiveLongGeneratorUnitTest.java | 60 ++++++++++++++++++ 3 files changed, 73 insertions(+), 72 deletions(-) rename core-java-modules/core-java-uuid/src/main/java/com/baeldung/uuid/{UUIDLongGenerator.java => UUIDPositiveLongGenerator.java} (68%) delete mode 100644 core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDLongGeneratorUnitTest.java create mode 100644 core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java diff --git a/core-java-modules/core-java-uuid/src/main/java/com/baeldung/uuid/UUIDLongGenerator.java b/core-java-modules/core-java-uuid/src/main/java/com/baeldung/uuid/UUIDPositiveLongGenerator.java similarity index 68% rename from core-java-modules/core-java-uuid/src/main/java/com/baeldung/uuid/UUIDLongGenerator.java rename to core-java-modules/core-java-uuid/src/main/java/com/baeldung/uuid/UUIDPositiveLongGenerator.java index 8ac71b1ce6..bc8177837c 100644 --- a/core-java-modules/core-java-uuid/src/main/java/com/baeldung/uuid/UUIDLongGenerator.java +++ b/core-java-modules/core-java-uuid/src/main/java/com/baeldung/uuid/UUIDPositiveLongGenerator.java @@ -3,17 +3,21 @@ package com.baeldung.uuid; import java.nio.ByteBuffer; import java.util.UUID; -public class UUIDLongGenerator { +/** + * Methods are called by reflection in the unit test + */ +@SuppressWarnings("unused") +public class UUIDPositiveLongGenerator { public long getLeastSignificantBits(){ - return UUID.randomUUID().getLeastSignificantBits(); + return Math.abs(UUID.randomUUID().getLeastSignificantBits()); } public long getMostSignificantBits(){ - return UUID.randomUUID().getMostSignificantBits(); + return Math.abs(UUID.randomUUID().getMostSignificantBits()); } public long gethashCode(){ - return UUID.randomUUID().toString().hashCode(); + return Math.abs(UUID.randomUUID().toString().hashCode()); } public long combineByteBuffer(){ @@ -21,21 +25,21 @@ public class UUIDLongGenerator { ByteBuffer bb = ByteBuffer.wrap(new byte[16]); bb.putLong(uuid.getMostSignificantBits()); bb.putLong(uuid.getLeastSignificantBits()); - bb.rewind(); // Kembalikan posisi buffer ke awal - return bb.getLong(); + bb.rewind(); + return Math.abs(bb.getLong()); } public long combineBitwise(){ UUID uniqueUUID; uniqueUUID = UUID.randomUUID(); - return (uniqueUUID.getMostSignificantBits() << 32) | (uniqueUUID.getLeastSignificantBits() & 0xFFFFFFFFL); + return Math.abs((uniqueUUID.getMostSignificantBits() << 32) | (uniqueUUID.getLeastSignificantBits() & 0xFFFFFFFFL)); } public long combineDirect(){ UUID uniqueUUID = UUID.randomUUID(); long mostSignificantBits = uniqueUUID.getMostSignificantBits(); long leastSignificantBits = uniqueUUID.getLeastSignificantBits(); - return mostSignificantBits ^ (leastSignificantBits >> 1); + return Math.abs(mostSignificantBits ^ (leastSignificantBits >> 1)); } public long combinePermutation(){ @@ -53,6 +57,6 @@ public class UUIDLongGenerator { for (byte b : uuidBytes) { result = (result << 8) | (b & 0xFF); } - return result; + return Math.abs(result); } } diff --git a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDLongGeneratorUnitTest.java b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDLongGeneratorUnitTest.java deleted file mode 100644 index 24add0a14a..0000000000 --- a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDLongGeneratorUnitTest.java +++ /dev/null @@ -1,63 +0,0 @@ -package com.baeldung.uuid; - -import org.junit.jupiter.api.Test; - -import java.lang.reflect.InvocationTargetException; -import java.lang.reflect.Method; -import java.text.DecimalFormat; -import java.util.HashSet; -import java.util.Set; -import java.util.concurrent.atomic.AtomicInteger; -import java.util.stream.IntStream; - -import static org.junit.jupiter.api.Assertions.assertTrue; - -public class UUIDLongGeneratorUnitTest { - final static int n = 1000000; - UUIDLongGenerator uuidLongGenerator = new UUIDLongGenerator(); - - @Test - void whenForeachGenerateLongValue_thenCollisionsCheck() { - printTableHeader(); - for (Method method : uuidLongGenerator.getClass().getDeclaredMethods()) { - collisionAndNegativeCheck(method); - } - } - - private void printTableHeader() { - System.out.format("%-30s %-15s %-15s %-15s %-15s%n", "Approach", "collisions", "negatives", "collision", "negative"); - System.out.format("%-30s %-15s %-15s %-15s %-15s%n", "(method name)", "count", "count", "probability", "probability"); - System.out.println("--------------------------------------------------------------------------------------------"); - } - - private void printOutput(String method, int collisionsCount, int negativeCount, double collisionsProbability, double negativeProbability) { - DecimalFormat decimalFormat = new DecimalFormat("#.#####"); - System.out.format("%-30s %-15s %-15s %-15s %-15s%n", method, collisionsCount, negativeCount, decimalFormat.format(collisionsProbability), decimalFormat.format(negativeProbability)); - } - - private void collisionAndNegativeCheck(Method method) { - Set uniqueValues = new HashSet<>(); - AtomicInteger collisions = new AtomicInteger(0); - AtomicInteger negative = new AtomicInteger(0); - - IntStream.range(0, n).forEach(i -> { - try { - long uniqueValue = (long) method.invoke(uuidLongGenerator); - if (!uniqueValues.add(uniqueValue)) { - collisions.incrementAndGet(); - } - if (uniqueValue < 0) { - negative.incrementAndGet(); - } - } catch (IllegalAccessException | InvocationTargetException e) { - throw new RuntimeException(e); - } - }); - - double collisionsProbability = (double) collisions.get() / n; - double negativeProbability = (double) negative.get() / n; - printOutput(method.getName(), collisions.get(), negative.get(), collisionsProbability, negativeProbability); - - assertTrue(collisionsProbability <= 0.001); // threshold = 0.001 - } -} diff --git a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java new file mode 100644 index 0000000000..2df49b20fd --- /dev/null +++ b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java @@ -0,0 +1,60 @@ +package com.baeldung.uuid; + +import org.junit.jupiter.api.Test; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.lang.reflect.InvocationTargetException; +import java.lang.reflect.Method; +import java.text.DecimalFormat; +import java.util.HashSet; +import java.util.Set; + +import static org.assertj.core.api.Assertions.assertThat; + +public class UUIDPositiveLongGeneratorUnitTest { + private final static int n = 1000000; + private final UUIDPositiveLongGenerator uuidLongGenerator = new UUIDPositiveLongGenerator(); + private final Logger logger = LoggerFactory.getLogger(UUIDPositiveLongGeneratorUnitTest.class); + + @Test + void whenForeachGenerateLongValue_thenCollisionsCheck() throws InvocationTargetException, IllegalAccessException { + printTableHeader(); + for (Method method : uuidLongGenerator.getClass().getDeclaredMethods()) { + collisionAndNegativeCheck(method); + } + } + + + private void printTableHeader() { + logger.info(String.format("%-30s %-15s %-15s %-15s %-15s", "Approach", "collisions", "negatives", "collision", "negative")); + logger.info(String.format("%-30s %-15s %-15s %-15s %-15s", "(method name)", "count", "count", "probability", "probability")); + logger.info("--------------------------------------------------------------------------------------------"); + } + + private void printOutput(String method, int collisionsCount, int negativeCount, double collisionsProbability, double negativeProbability) { + DecimalFormat decimalFormat = new DecimalFormat("#.#####"); + //logger.info(String.format("%-30s %-15s %-15s %-15s %-15s", method, collisionsCount, negativeCount, decimalFormat.format(collisionsProbability), decimalFormat.format(negativeProbability))); + logger.info("%-30s{} %-15s{} %-15s{} %-15s{} %-15s{}", method, collisionsCount, negativeCount, decimalFormat.format(collisionsProbability), decimalFormat.format(negativeProbability)); + } + + + private void collisionAndNegativeCheck(Method method) throws InvocationTargetException, IllegalAccessException { + Set uniqueValues = new HashSet<>(); + int collisions = 0; + int negative = 0; + for (int i = 0; i < n; i++) { + long uniqueValue = (long) method.invoke(uuidLongGenerator); + if (!uniqueValues.add(uniqueValue)) { + collisions++; + } + if (uniqueValue < 0) { + negative++; + } + } + double collisionsProbability = (double) collisions / n; + double negativeProbability = (double) negative / n; + printOutput(method.getName(), collisions, negative, collisionsProbability, negativeProbability); + assertThat(collisionsProbability).isLessThan(0.001); + } +} From 579f35981e6910a3b9957f6a95300edcd5ce7015 Mon Sep 17 00:00:00 2001 From: "@hangga" Date: Wed, 1 Nov 2023 11:01:27 +0700 Subject: [PATCH 05/24] update, rename class --- .../uuid/UUIDLongGeneratorUnitTest.java | 60 ------------------- .../UUIDPositiveLongGeneratorUnitTest.java | 6 +- 2 files changed, 3 insertions(+), 63 deletions(-) delete mode 100644 core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDLongGeneratorUnitTest.java diff --git a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDLongGeneratorUnitTest.java b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDLongGeneratorUnitTest.java deleted file mode 100644 index fde726d259..0000000000 --- a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDLongGeneratorUnitTest.java +++ /dev/null @@ -1,60 +0,0 @@ -package com.baeldung.uuid; - -import org.apache.log4j.Logger; -import org.junit.jupiter.api.Test; - -import java.lang.reflect.InvocationTargetException; -import java.lang.reflect.Method; -import java.text.DecimalFormat; -import java.util.HashSet; -import java.util.Set; - -import static org.assertj.core.api.Assertions.assertThat; - -public class UUIDLongGeneratorUnitTest { - private final static int n = 1000000; - private final static double COLLISION_THRESHOLD = 0.001; - private static final Logger logger = Logger.getLogger(UUIDLongGeneratorUnitTest.class); - private final UUIDPositiveLongGenerator uuidLongGenerator = new UUIDPositiveLongGenerator(); - - @Test - void whenForeachGenerateLongValue_thenCollisionsCheck() throws InvocationTargetException, IllegalAccessException { - printTableHeader(); - for (Method method : uuidLongGenerator.getClass().getDeclaredMethods()) { - collisionAndNegativeCheck(method); - } - } - - private void printTableHeader() { - logger.info(String.format("%-30s %-15s %-15s %-15s %-15s%n", "Approach", "collisions", "negatives", "collision", "negative")); - logger.info(String.format("%-30s %-15s %-15s %-15s %-15s%n", "(method name)", "count", "count", "probability", "probability")); - System.out.println("--------------------------------------------------------------------------------------------"); - } - - private void printOutput(String method, int collisionsCount, int negativeCount, double collisionsProbability, double negativeProbability) { - DecimalFormat decimalFormat = new DecimalFormat("#.#####"); - logger.info(String.format("%-30s %-15s %-15s %-15s %-15s", method, collisionsCount, negativeCount, decimalFormat.format(collisionsProbability), decimalFormat.format(negativeProbability))); - } - - private void collisionAndNegativeCheck(Method method) throws InvocationTargetException, IllegalAccessException { - Set uniqueValues = new HashSet<>(); - int collisions = 0; - int negative = 0; - - for (int i = 0; i < n; i++) { - long uniqueValue = (long) method.invoke(uuidLongGenerator); - if (!uniqueValues.add(uniqueValue)) { - collisions++; - } - if (uniqueValue < 0) { - negative++; - } - } - - double collisionsProbability = (double) collisions / n; - double negativeProbability = (double) negative / n; - printOutput(method.getName(), collisions, negative, collisionsProbability, negativeProbability); - - assertThat(collisionsProbability).isLessThan(COLLISION_THRESHOLD); - } -} diff --git a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java index 2df49b20fd..c910a6eb16 100644 --- a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java +++ b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java @@ -14,6 +14,7 @@ import static org.assertj.core.api.Assertions.assertThat; public class UUIDPositiveLongGeneratorUnitTest { private final static int n = 1000000; + private final static double COLLISION_THRESHOLD = 0.001; private final UUIDPositiveLongGenerator uuidLongGenerator = new UUIDPositiveLongGenerator(); private final Logger logger = LoggerFactory.getLogger(UUIDPositiveLongGeneratorUnitTest.class); @@ -34,8 +35,7 @@ public class UUIDPositiveLongGeneratorUnitTest { private void printOutput(String method, int collisionsCount, int negativeCount, double collisionsProbability, double negativeProbability) { DecimalFormat decimalFormat = new DecimalFormat("#.#####"); - //logger.info(String.format("%-30s %-15s %-15s %-15s %-15s", method, collisionsCount, negativeCount, decimalFormat.format(collisionsProbability), decimalFormat.format(negativeProbability))); - logger.info("%-30s{} %-15s{} %-15s{} %-15s{} %-15s{}", method, collisionsCount, negativeCount, decimalFormat.format(collisionsProbability), decimalFormat.format(negativeProbability)); + logger.info(String.format("%-30s %-15s %-15s %-15s %-15s", method, collisionsCount, negativeCount, decimalFormat.format(collisionsProbability), decimalFormat.format(negativeProbability))); } @@ -55,6 +55,6 @@ public class UUIDPositiveLongGeneratorUnitTest { double collisionsProbability = (double) collisions / n; double negativeProbability = (double) negative / n; printOutput(method.getName(), collisions, negative, collisionsProbability, negativeProbability); - assertThat(collisionsProbability).isLessThan(0.001); + assertThat(collisionsProbability).isLessThan(COLLISION_THRESHOLD); } } From 10ddc978542620d06d1ab34cf0ce71e6c5b56210 Mon Sep 17 00:00:00 2001 From: "@hangga" Date: Wed, 1 Nov 2023 12:44:04 +0700 Subject: [PATCH 06/24] update --- .../com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java index c910a6eb16..5847ef44fb 100644 --- a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java +++ b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java @@ -22,7 +22,7 @@ public class UUIDPositiveLongGeneratorUnitTest { void whenForeachGenerateLongValue_thenCollisionsCheck() throws InvocationTargetException, IllegalAccessException { printTableHeader(); for (Method method : uuidLongGenerator.getClass().getDeclaredMethods()) { - collisionAndNegativeCheck(method); + collisionCheck(method); } } @@ -39,7 +39,7 @@ public class UUIDPositiveLongGeneratorUnitTest { } - private void collisionAndNegativeCheck(Method method) throws InvocationTargetException, IllegalAccessException { + private void collisionCheck(Method method) throws InvocationTargetException, IllegalAccessException { Set uniqueValues = new HashSet<>(); int collisions = 0; int negative = 0; From e0ca0be76af2e7b8a96a5d4e1c5165b1a0967b9d Mon Sep 17 00:00:00 2001 From: "@hangga" Date: Wed, 1 Nov 2023 16:27:09 +0700 Subject: [PATCH 07/24] positive --- .../uuid/UUIDPositiveLongGeneratorUnitTest.java | 16 +++++----------- 1 file changed, 5 insertions(+), 11 deletions(-) diff --git a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java index 5847ef44fb..cd538af523 100644 --- a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java +++ b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java @@ -28,33 +28,27 @@ public class UUIDPositiveLongGeneratorUnitTest { private void printTableHeader() { - logger.info(String.format("%-30s %-15s %-15s %-15s %-15s", "Approach", "collisions", "negatives", "collision", "negative")); - logger.info(String.format("%-30s %-15s %-15s %-15s %-15s", "(method name)", "count", "count", "probability", "probability")); - logger.info("--------------------------------------------------------------------------------------------"); + logger.info(String.format("%-30s %-15s %-15s", "Approach(method name)", "collisions", "probability")); + logger.info("-----------------------------------------------------------------------"); } - private void printOutput(String method, int collisionsCount, int negativeCount, double collisionsProbability, double negativeProbability) { + private void printOutput(String method, int collisionsCount, double collisionsProbability) { DecimalFormat decimalFormat = new DecimalFormat("#.#####"); - logger.info(String.format("%-30s %-15s %-15s %-15s %-15s", method, collisionsCount, negativeCount, decimalFormat.format(collisionsProbability), decimalFormat.format(negativeProbability))); + logger.info(String.format("%-30s %-15s %-15s", method, collisionsCount, decimalFormat.format(collisionsProbability))); } private void collisionCheck(Method method) throws InvocationTargetException, IllegalAccessException { Set uniqueValues = new HashSet<>(); int collisions = 0; - int negative = 0; for (int i = 0; i < n; i++) { long uniqueValue = (long) method.invoke(uuidLongGenerator); if (!uniqueValues.add(uniqueValue)) { collisions++; } - if (uniqueValue < 0) { - negative++; - } } double collisionsProbability = (double) collisions / n; - double negativeProbability = (double) negative / n; - printOutput(method.getName(), collisions, negative, collisionsProbability, negativeProbability); + printOutput(method.getName(), collisions, collisionsProbability); assertThat(collisionsProbability).isLessThan(COLLISION_THRESHOLD); } } From 3286aab10c4b7a438e5b24c0a80bd368d7ad89e5 Mon Sep 17 00:00:00 2001 From: "@hangga" Date: Wed, 1 Nov 2023 18:24:02 +0700 Subject: [PATCH 08/24] bit 16 to 64 --- .../main/java/com/baeldung/uuid/UUIDPositiveLongGenerator.java | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/core-java-modules/core-java-uuid/src/main/java/com/baeldung/uuid/UUIDPositiveLongGenerator.java b/core-java-modules/core-java-uuid/src/main/java/com/baeldung/uuid/UUIDPositiveLongGenerator.java index bc8177837c..bb3e0223f3 100644 --- a/core-java-modules/core-java-uuid/src/main/java/com/baeldung/uuid/UUIDPositiveLongGenerator.java +++ b/core-java-modules/core-java-uuid/src/main/java/com/baeldung/uuid/UUIDPositiveLongGenerator.java @@ -22,7 +22,7 @@ public class UUIDPositiveLongGenerator { public long combineByteBuffer(){ UUID uuid = UUID.randomUUID(); - ByteBuffer bb = ByteBuffer.wrap(new byte[16]); + ByteBuffer bb = ByteBuffer.wrap(new byte[64]); bb.putLong(uuid.getMostSignificantBits()); bb.putLong(uuid.getLeastSignificantBits()); bb.rewind(); From 039753af1fc5b661ba0a15524814d9b650988264 Mon Sep 17 00:00:00 2001 From: "@hangga" Date: Wed, 1 Nov 2023 18:26:54 +0700 Subject: [PATCH 09/24] back to 16 --- .../main/java/com/baeldung/uuid/UUIDPositiveLongGenerator.java | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/core-java-modules/core-java-uuid/src/main/java/com/baeldung/uuid/UUIDPositiveLongGenerator.java b/core-java-modules/core-java-uuid/src/main/java/com/baeldung/uuid/UUIDPositiveLongGenerator.java index bb3e0223f3..bc8177837c 100644 --- a/core-java-modules/core-java-uuid/src/main/java/com/baeldung/uuid/UUIDPositiveLongGenerator.java +++ b/core-java-modules/core-java-uuid/src/main/java/com/baeldung/uuid/UUIDPositiveLongGenerator.java @@ -22,7 +22,7 @@ public class UUIDPositiveLongGenerator { public long combineByteBuffer(){ UUID uuid = UUID.randomUUID(); - ByteBuffer bb = ByteBuffer.wrap(new byte[64]); + ByteBuffer bb = ByteBuffer.wrap(new byte[16]); bb.putLong(uuid.getMostSignificantBits()); bb.putLong(uuid.getLeastSignificantBits()); bb.rewind(); From b946f580f48f8dd33a12f192544aea0176a6846b Mon Sep 17 00:00:00 2001 From: Hangga Aji Sayekti Date: Thu, 2 Nov 2023 09:39:17 +0700 Subject: [PATCH 10/24] Update core-java-modules/core-java-uuid/src/main/java/com/baeldung/uuid/UUIDPositiveLongGenerator.java Minor style issue: put a space between () and { in each of these methods Co-authored-by: Liam Williams --- .../main/java/com/baeldung/uuid/UUIDPositiveLongGenerator.java | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/core-java-modules/core-java-uuid/src/main/java/com/baeldung/uuid/UUIDPositiveLongGenerator.java b/core-java-modules/core-java-uuid/src/main/java/com/baeldung/uuid/UUIDPositiveLongGenerator.java index bc8177837c..b47fee1968 100644 --- a/core-java-modules/core-java-uuid/src/main/java/com/baeldung/uuid/UUIDPositiveLongGenerator.java +++ b/core-java-modules/core-java-uuid/src/main/java/com/baeldung/uuid/UUIDPositiveLongGenerator.java @@ -8,7 +8,7 @@ import java.util.UUID; */ @SuppressWarnings("unused") public class UUIDPositiveLongGenerator { - public long getLeastSignificantBits(){ + public long getLeastSignificantBits() { return Math.abs(UUID.randomUUID().getLeastSignificantBits()); } From 9fe75192ecea51637320985266159328aca02c4a Mon Sep 17 00:00:00 2001 From: Hangga Aji Sayekti Date: Thu, 2 Nov 2023 09:39:43 +0700 Subject: [PATCH 11/24] Update core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java assert that the value is positive Co-authored-by: Liam Williams --- .../com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java | 1 + 1 file changed, 1 insertion(+) diff --git a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java index cd538af523..854279446b 100644 --- a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java +++ b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java @@ -43,6 +43,7 @@ public class UUIDPositiveLongGeneratorUnitTest { int collisions = 0; for (int i = 0; i < n; i++) { long uniqueValue = (long) method.invoke(uuidLongGenerator); + assertThat(uniqueValue).isPositive(); if (!uniqueValues.add(uniqueValue)) { collisions++; } From f25f06795b20c4d8947efcbaf779a02bc25b32e3 Mon Sep 17 00:00:00 2001 From: Hangga Aji Sayekti Date: Thu, 2 Nov 2023 09:40:04 +0700 Subject: [PATCH 12/24] Update core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java Simplify the throws clause Co-authored-by: Liam Williams --- .../com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java index 854279446b..90ba11984f 100644 --- a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java +++ b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java @@ -38,7 +38,7 @@ public class UUIDPositiveLongGeneratorUnitTest { } - private void collisionCheck(Method method) throws InvocationTargetException, IllegalAccessException { + private void collisionCheck(Method method) throws Exception { Set uniqueValues = new HashSet<>(); int collisions = 0; for (int i = 0; i < n; i++) { From a5d0a15419cfcfeb3d0843e381188a58996bbe3e Mon Sep 17 00:00:00 2001 From: Hangga Aji Sayekti Date: Thu, 2 Nov 2023 09:40:20 +0700 Subject: [PATCH 13/24] Update core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java Simplify the throws clause Co-authored-by: Liam Williams --- .../com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java index 90ba11984f..ebb061216b 100644 --- a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java +++ b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java @@ -19,7 +19,7 @@ public class UUIDPositiveLongGeneratorUnitTest { private final Logger logger = LoggerFactory.getLogger(UUIDPositiveLongGeneratorUnitTest.class); @Test - void whenForeachGenerateLongValue_thenCollisionsCheck() throws InvocationTargetException, IllegalAccessException { + void whenForeachGenerateLongValue_thenCollisionsCheck() throws Exception { printTableHeader(); for (Method method : uuidLongGenerator.getClass().getDeclaredMethods()) { collisionCheck(method); From 8f1a091a431bcd423d59343327f8a9b8540fc9df Mon Sep 17 00:00:00 2001 From: "@hangga" Date: Thu, 2 Nov 2023 09:42:31 +0700 Subject: [PATCH 14/24] update : add space after () --- .../com/baeldung/uuid/UUIDPositiveLongGenerator.java | 12 ++++++------ .../uuid/UUIDPositiveLongGeneratorUnitTest.java | 7 +++---- 2 files changed, 9 insertions(+), 10 deletions(-) diff --git a/core-java-modules/core-java-uuid/src/main/java/com/baeldung/uuid/UUIDPositiveLongGenerator.java b/core-java-modules/core-java-uuid/src/main/java/com/baeldung/uuid/UUIDPositiveLongGenerator.java index b47fee1968..7b98c05684 100644 --- a/core-java-modules/core-java-uuid/src/main/java/com/baeldung/uuid/UUIDPositiveLongGenerator.java +++ b/core-java-modules/core-java-uuid/src/main/java/com/baeldung/uuid/UUIDPositiveLongGenerator.java @@ -12,15 +12,15 @@ public class UUIDPositiveLongGenerator { return Math.abs(UUID.randomUUID().getLeastSignificantBits()); } - public long getMostSignificantBits(){ + public long getMostSignificantBits() { return Math.abs(UUID.randomUUID().getMostSignificantBits()); } - public long gethashCode(){ + public long gethashCode() { return Math.abs(UUID.randomUUID().toString().hashCode()); } - public long combineByteBuffer(){ + public long combineByteBuffer() { UUID uuid = UUID.randomUUID(); ByteBuffer bb = ByteBuffer.wrap(new byte[16]); bb.putLong(uuid.getMostSignificantBits()); @@ -29,20 +29,20 @@ public class UUIDPositiveLongGenerator { return Math.abs(bb.getLong()); } - public long combineBitwise(){ + public long combineBitwise() { UUID uniqueUUID; uniqueUUID = UUID.randomUUID(); return Math.abs((uniqueUUID.getMostSignificantBits() << 32) | (uniqueUUID.getLeastSignificantBits() & 0xFFFFFFFFL)); } - public long combineDirect(){ + public long combineDirect() { UUID uniqueUUID = UUID.randomUUID(); long mostSignificantBits = uniqueUUID.getMostSignificantBits(); long leastSignificantBits = uniqueUUID.getLeastSignificantBits(); return Math.abs(mostSignificantBits ^ (leastSignificantBits >> 1)); } - public long combinePermutation(){ + public long combinePermutation() { UUID uuid = UUID.randomUUID(); long mostSigBits = uuid.getMostSignificantBits(); long leastSigBits = uuid.getLeastSignificantBits(); diff --git a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java index ebb061216b..cc377254c4 100644 --- a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java +++ b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java @@ -4,7 +4,6 @@ import org.junit.jupiter.api.Test; import org.slf4j.Logger; import org.slf4j.LoggerFactory; -import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; import java.text.DecimalFormat; import java.util.HashSet; @@ -13,7 +12,7 @@ import java.util.Set; import static org.assertj.core.api.Assertions.assertThat; public class UUIDPositiveLongGeneratorUnitTest { - private final static int n = 1000000; + private final static int N = 1000000; private final static double COLLISION_THRESHOLD = 0.001; private final UUIDPositiveLongGenerator uuidLongGenerator = new UUIDPositiveLongGenerator(); private final Logger logger = LoggerFactory.getLogger(UUIDPositiveLongGeneratorUnitTest.class); @@ -41,14 +40,14 @@ public class UUIDPositiveLongGeneratorUnitTest { private void collisionCheck(Method method) throws Exception { Set uniqueValues = new HashSet<>(); int collisions = 0; - for (int i = 0; i < n; i++) { + for (int i = 0; i < N; i++) { long uniqueValue = (long) method.invoke(uuidLongGenerator); assertThat(uniqueValue).isPositive(); if (!uniqueValues.add(uniqueValue)) { collisions++; } } - double collisionsProbability = (double) collisions / n; + double collisionsProbability = (double) collisions / N; printOutput(method.getName(), collisions, collisionsProbability); assertThat(collisionsProbability).isLessThan(COLLISION_THRESHOLD); } From 69d17b634d22690d4a7981287126e9837a5c9e6d Mon Sep 17 00:00:00 2001 From: "@hangga" Date: Thu, 2 Nov 2023 11:25:19 +0700 Subject: [PATCH 15/24] N to NUMBER_OF_CHECKS --- .../baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java index cc377254c4..9db7a2f271 100644 --- a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java +++ b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java @@ -12,7 +12,7 @@ import java.util.Set; import static org.assertj.core.api.Assertions.assertThat; public class UUIDPositiveLongGeneratorUnitTest { - private final static int N = 1000000; + private final static int NUMBER_OF_CHECKS = 1000000; private final static double COLLISION_THRESHOLD = 0.001; private final UUIDPositiveLongGenerator uuidLongGenerator = new UUIDPositiveLongGenerator(); private final Logger logger = LoggerFactory.getLogger(UUIDPositiveLongGeneratorUnitTest.class); @@ -40,14 +40,14 @@ public class UUIDPositiveLongGeneratorUnitTest { private void collisionCheck(Method method) throws Exception { Set uniqueValues = new HashSet<>(); int collisions = 0; - for (int i = 0; i < N; i++) { + for (int i = 0; i < NUMBER_OF_CHECKS; i++) { long uniqueValue = (long) method.invoke(uuidLongGenerator); assertThat(uniqueValue).isPositive(); if (!uniqueValues.add(uniqueValue)) { collisions++; } } - double collisionsProbability = (double) collisions / N; + double collisionsProbability = (double) collisions / NUMBER_OF_CHECKS; printOutput(method.getName(), collisions, collisionsProbability); assertThat(collisionsProbability).isLessThan(COLLISION_THRESHOLD); } From 0f222559dc3a77c7e557682b7b410bc2305058e2 Mon Sep 17 00:00:00 2001 From: "@hangga" Date: Thu, 2 Nov 2023 14:16:43 +0700 Subject: [PATCH 16/24] simplyfying log --- .../core-java-uuid/src/test/resources/logback.xml | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/core-java-modules/core-java-uuid/src/test/resources/logback.xml b/core-java-modules/core-java-uuid/src/test/resources/logback.xml index 56af2d397e..092215ceed 100644 --- a/core-java-modules/core-java-uuid/src/test/resources/logback.xml +++ b/core-java-modules/core-java-uuid/src/test/resources/logback.xml @@ -2,8 +2,8 @@ - %d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n - + %d{HH:mm:ss} - %msg%n + @@ -12,6 +12,7 @@ + From 7cc4de47ef85d2002fd9a13db57e3c455fd9e2c6 Mon Sep 17 00:00:00 2001 From: "@hangga" Date: Thu, 2 Nov 2023 16:55:49 +0700 Subject: [PATCH 17/24] remove some space --- .../com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java | 2 -- 1 file changed, 2 deletions(-) diff --git a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java index 9db7a2f271..fab07df2a0 100644 --- a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java +++ b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java @@ -25,7 +25,6 @@ public class UUIDPositiveLongGeneratorUnitTest { } } - private void printTableHeader() { logger.info(String.format("%-30s %-15s %-15s", "Approach(method name)", "collisions", "probability")); logger.info("-----------------------------------------------------------------------"); @@ -36,7 +35,6 @@ public class UUIDPositiveLongGeneratorUnitTest { logger.info(String.format("%-30s %-15s %-15s", method, collisionsCount, decimalFormat.format(collisionsProbability))); } - private void collisionCheck(Method method) throws Exception { Set uniqueValues = new HashSet<>(); int collisions = 0; From 18220b12af536a7c75860210c86ec9ea6ba0dc55 Mon Sep 17 00:00:00 2001 From: Hangga Aji Sayekti Date: Thu, 2 Nov 2023 21:05:07 +0700 Subject: [PATCH 18/24] Update core-java-modules/core-java-uuid/src/test/resources/logback.xml Ok.. Co-authored-by: Liam Williams --- core-java-modules/core-java-uuid/src/test/resources/logback.xml | 1 - 1 file changed, 1 deletion(-) diff --git a/core-java-modules/core-java-uuid/src/test/resources/logback.xml b/core-java-modules/core-java-uuid/src/test/resources/logback.xml index 092215ceed..8d3b4ff505 100644 --- a/core-java-modules/core-java-uuid/src/test/resources/logback.xml +++ b/core-java-modules/core-java-uuid/src/test/resources/logback.xml @@ -12,7 +12,6 @@ - From 39bc0b9eaad2eb6a2ee06d30a965496252ffeccf Mon Sep 17 00:00:00 2001 From: "@hangga" Date: Thu, 2 Nov 2023 21:08:06 +0700 Subject: [PATCH 19/24] logback --- .../core-java-uuid/src/test/resources/logback.xml | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/core-java-modules/core-java-uuid/src/test/resources/logback.xml b/core-java-modules/core-java-uuid/src/test/resources/logback.xml index 8d3b4ff505..a076f8db47 100644 --- a/core-java-modules/core-java-uuid/src/test/resources/logback.xml +++ b/core-java-modules/core-java-uuid/src/test/resources/logback.xml @@ -2,8 +2,7 @@ - %d{HH:mm:ss} - %msg%n - + %d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n From 899700f27e7357cdb27653c0cb7be1a06323888d Mon Sep 17 00:00:00 2001 From: "@hangga" Date: Fri, 3 Nov 2023 15:45:12 +0700 Subject: [PATCH 20/24] [Update] add time field --- .../UUIDPositiveLongGeneratorUnitTest.java | 44 ++++++++++++++++--- 1 file changed, 37 insertions(+), 7 deletions(-) diff --git a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java index fab07df2a0..62b059f0e5 100644 --- a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java +++ b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java @@ -6,8 +6,7 @@ import org.slf4j.LoggerFactory; import java.lang.reflect.Method; import java.text.DecimalFormat; -import java.util.HashSet; -import java.util.Set; +import java.util.*; import static org.assertj.core.api.Assertions.assertThat; @@ -17,8 +16,11 @@ public class UUIDPositiveLongGeneratorUnitTest { private final UUIDPositiveLongGenerator uuidLongGenerator = new UUIDPositiveLongGenerator(); private final Logger logger = LoggerFactory.getLogger(UUIDPositiveLongGeneratorUnitTest.class); + List times = new ArrayList<>(); + @Test void whenForeachGenerateLongValue_thenCollisionsCheck() throws Exception { + times.clear(); printTableHeader(); for (Method method : uuidLongGenerator.getClass().getDeclaredMethods()) { collisionCheck(method); @@ -26,16 +28,17 @@ public class UUIDPositiveLongGeneratorUnitTest { } private void printTableHeader() { - logger.info(String.format("%-30s %-15s %-15s", "Approach(method name)", "collisions", "probability")); - logger.info("-----------------------------------------------------------------------"); + logger.info(String.format("%-30s %15s %15s %15s", "Approach(method name)", "collisions", "probability","Time")); + logger.info("--------------------------------------------------------------------------------"); } - private void printOutput(String method, int collisionsCount, double collisionsProbability) { + private void printOutput(String method, int collisionsCount, double collisionsProbability, String time) { DecimalFormat decimalFormat = new DecimalFormat("#.#####"); - logger.info(String.format("%-30s %-15s %-15s", method, collisionsCount, decimalFormat.format(collisionsProbability))); + logger.info(String.format("%-30s %15s %15s %15s", method, collisionsCount, decimalFormat.format(collisionsProbability),time)); } private void collisionCheck(Method method) throws Exception { + long start = System.currentTimeMillis(); Set uniqueValues = new HashSet<>(); int collisions = 0; for (int i = 0; i < NUMBER_OF_CHECKS; i++) { @@ -46,7 +49,34 @@ public class UUIDPositiveLongGeneratorUnitTest { } } double collisionsProbability = (double) collisions / NUMBER_OF_CHECKS; - printOutput(method.getName(), collisions, collisionsProbability); + long end = System.currentTimeMillis(); + String time = convertMillisToTime(end - start); + printOutput(method.getName(), collisions, collisionsProbability, time); assertThat(collisionsProbability).isLessThan(COLLISION_THRESHOLD); + + } + + private String convertMillisToTime(long currentTimeMillis) { + + long totalMilliseconds = currentTimeMillis % 1000; + times.add(totalMilliseconds); + long totalSeconds = (currentTimeMillis / 1000) % 60; + long totalMinutes = (currentTimeMillis / 60000) % 60; + long hours = (currentTimeMillis / 3600000); + StringJoiner stringBuffer = new StringJoiner(""); + + if (hours > 0){ + stringBuffer.add(hours+"h "); + } + if (totalMinutes > 0){ + stringBuffer.add(totalMinutes+" m "); + } + if (totalSeconds > 0){ + stringBuffer.add(totalSeconds+" s "); + } + if (totalMilliseconds > 0){ + stringBuffer.add(totalMilliseconds+" ms"); + } + return stringBuffer.toString(); } } From b7bc968da2a4f81850e2c7415e22ed0ccc4c6cd7 Mon Sep 17 00:00:00 2001 From: Hangga Aji Sayekti Date: Fri, 3 Nov 2023 17:13:48 +0700 Subject: [PATCH 21/24] Update core-java-modules/core-java-uuid/src/main/java/com/baeldung/uuid/UUIDPositiveLongGenerator.java Oh yeah.. Co-authored-by: Liam Williams --- .../main/java/com/baeldung/uuid/UUIDPositiveLongGenerator.java | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/core-java-modules/core-java-uuid/src/main/java/com/baeldung/uuid/UUIDPositiveLongGenerator.java b/core-java-modules/core-java-uuid/src/main/java/com/baeldung/uuid/UUIDPositiveLongGenerator.java index 7b98c05684..13b32be856 100644 --- a/core-java-modules/core-java-uuid/src/main/java/com/baeldung/uuid/UUIDPositiveLongGenerator.java +++ b/core-java-modules/core-java-uuid/src/main/java/com/baeldung/uuid/UUIDPositiveLongGenerator.java @@ -16,7 +16,7 @@ public class UUIDPositiveLongGenerator { return Math.abs(UUID.randomUUID().getMostSignificantBits()); } - public long gethashCode() { + public long getHashCode() { return Math.abs(UUID.randomUUID().toString().hashCode()); } From 32940c41e4a6f0db1a29e2093f7c79ae83e7e2d9 Mon Sep 17 00:00:00 2001 From: "@hangga" Date: Sat, 4 Nov 2023 15:28:49 +0700 Subject: [PATCH 22/24] update time test --- .../com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java index 62b059f0e5..70b47df163 100644 --- a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java +++ b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java @@ -28,13 +28,13 @@ public class UUIDPositiveLongGeneratorUnitTest { } private void printTableHeader() { - logger.info(String.format("%-30s %15s %15s %15s", "Approach(method name)", "collisions", "probability","Time")); + logger.info(String.format("%-25s %15s %15s %15s", "Approach(method name)", "collisions", "probability","Testing Time")); logger.info("--------------------------------------------------------------------------------"); } private void printOutput(String method, int collisionsCount, double collisionsProbability, String time) { DecimalFormat decimalFormat = new DecimalFormat("#.#####"); - logger.info(String.format("%-30s %15s %15s %15s", method, collisionsCount, decimalFormat.format(collisionsProbability),time)); + logger.info(String.format("%-25s %15s %15s %15s", method, collisionsCount, decimalFormat.format(collisionsProbability),time)); } private void collisionCheck(Method method) throws Exception { From 0c8b5bd210b716979891651a7af36582987c6183 Mon Sep 17 00:00:00 2001 From: "@hangga" Date: Sat, 18 Nov 2023 06:09:14 +0700 Subject: [PATCH 23/24] retry with colision --- .../baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java index 70b47df163..27ac4fe51e 100644 --- a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java +++ b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java @@ -56,6 +56,13 @@ public class UUIDPositiveLongGeneratorUnitTest { } + private boolean isUnique(long value) { + // Implementasikan logika pengecekan keunikan, misalnya, dengan memeriksa dalam database + // Mengembalikan true jika nilai unik, false jika ada tumbukan + return true; // Implementasikan sesuai kebutuhan aplikasi Anda + } + + private String convertMillisToTime(long currentTimeMillis) { long totalMilliseconds = currentTimeMillis % 1000; From 213fb362a0f94947f85e85eb9dafd4637f1daf1c Mon Sep 17 00:00:00 2001 From: "@hangga" Date: Sat, 18 Nov 2023 14:17:19 +0700 Subject: [PATCH 24/24] simplyfiying test --- .../UUIDPositiveLongGeneratorUnitTest.java | 77 +++---------------- 1 file changed, 10 insertions(+), 67 deletions(-) diff --git a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java index 27ac4fe51e..756bee94e6 100644 --- a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java +++ b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDPositiveLongGeneratorUnitTest.java @@ -1,89 +1,32 @@ package com.baeldung.uuid; import org.junit.jupiter.api.Test; -import org.slf4j.Logger; -import org.slf4j.LoggerFactory; import java.lang.reflect.Method; -import java.text.DecimalFormat; -import java.util.*; +import java.util.HashSet; +import java.util.Set; import static org.assertj.core.api.Assertions.assertThat; public class UUIDPositiveLongGeneratorUnitTest { - private final static int NUMBER_OF_CHECKS = 1000000; - private final static double COLLISION_THRESHOLD = 0.001; - private final UUIDPositiveLongGenerator uuidLongGenerator = new UUIDPositiveLongGenerator(); - private final Logger logger = LoggerFactory.getLogger(UUIDPositiveLongGeneratorUnitTest.class); - List times = new ArrayList<>(); + //private final UUIDPositiveLongGenerator uuidLongGenerator = new UUIDPositiveLongGenerator(); + + Set uniqueValues = new HashSet<>(); @Test void whenForeachGenerateLongValue_thenCollisionsCheck() throws Exception { - times.clear(); - printTableHeader(); + UUIDPositiveLongGenerator uuidLongGenerator = new UUIDPositiveLongGenerator(); for (Method method : uuidLongGenerator.getClass().getDeclaredMethods()) { - collisionCheck(method); - } - } - - private void printTableHeader() { - logger.info(String.format("%-25s %15s %15s %15s", "Approach(method name)", "collisions", "probability","Testing Time")); - logger.info("--------------------------------------------------------------------------------"); - } - - private void printOutput(String method, int collisionsCount, double collisionsProbability, String time) { - DecimalFormat decimalFormat = new DecimalFormat("#.#####"); - logger.info(String.format("%-25s %15s %15s %15s", method, collisionsCount, decimalFormat.format(collisionsProbability),time)); - } - - private void collisionCheck(Method method) throws Exception { - long start = System.currentTimeMillis(); - Set uniqueValues = new HashSet<>(); - int collisions = 0; - for (int i = 0; i < NUMBER_OF_CHECKS; i++) { - long uniqueValue = (long) method.invoke(uuidLongGenerator); + long uniqueValue; + do uniqueValue = (long) method.invoke(uuidLongGenerator); while (!isUnique(uniqueValue)); assertThat(uniqueValue).isPositive(); - if (!uniqueValues.add(uniqueValue)) { - collisions++; - } } - double collisionsProbability = (double) collisions / NUMBER_OF_CHECKS; - long end = System.currentTimeMillis(); - String time = convertMillisToTime(end - start); - printOutput(method.getName(), collisions, collisionsProbability, time); - assertThat(collisionsProbability).isLessThan(COLLISION_THRESHOLD); - } private boolean isUnique(long value) { - // Implementasikan logika pengecekan keunikan, misalnya, dengan memeriksa dalam database - // Mengembalikan true jika nilai unik, false jika ada tumbukan - return true; // Implementasikan sesuai kebutuhan aplikasi Anda + // Implement uniqueness checking logic, for example, by checking in the database + return uniqueValues.add(value); } - - private String convertMillisToTime(long currentTimeMillis) { - - long totalMilliseconds = currentTimeMillis % 1000; - times.add(totalMilliseconds); - long totalSeconds = (currentTimeMillis / 1000) % 60; - long totalMinutes = (currentTimeMillis / 60000) % 60; - long hours = (currentTimeMillis / 3600000); - StringJoiner stringBuffer = new StringJoiner(""); - - if (hours > 0){ - stringBuffer.add(hours+"h "); - } - if (totalMinutes > 0){ - stringBuffer.add(totalMinutes+" m "); - } - if (totalSeconds > 0){ - stringBuffer.add(totalSeconds+" s "); - } - if (totalMilliseconds > 0){ - stringBuffer.add(totalMilliseconds+" ms"); - } - return stringBuffer.toString(); - } }