diff --git a/core-java-modules/core-java-11/src/test/java/com/baeldung/patternreuse/PatternJava11UnitTest.java b/core-java-modules/core-java-11/src/test/java/com/baeldung/patternreuse/PatternJava11UnitTest.java new file mode 100644 index 0000000000..94c8a39c95 --- /dev/null +++ b/core-java-modules/core-java-11/src/test/java/com/baeldung/patternreuse/PatternJava11UnitTest.java @@ -0,0 +1,29 @@ +package com.baeldung.patternreuse; + +import org.junit.jupiter.api.Test; + +import java.util.Arrays; +import java.util.List; +import java.util.function.Predicate; +import java.util.regex.Pattern; +import java.util.stream.Collectors; + +import static org.junit.Assert.assertFalse; +import static org.junit.Assert.assertTrue; + +public class PatternJava11UnitTest { + + @Test + public void givenPreCompiledPattern_whenCallAsMatchPredicate_thenReturnMatchPredicateToMatchesThePatternInTheListElements() { + List namesToValidate = Arrays.asList("Fabio Silva", "Fabio Luis Silva"); + Pattern firstLastNamePreCompiledPattern = Pattern.compile("[a-zA-Z]{3,} [a-zA-Z]{3,}"); + + Predicate patternAsMatchPredicate = firstLastNamePreCompiledPattern.asMatchPredicate(); + List validatedNames = namesToValidate.stream() + .filter(patternAsMatchPredicate) + .collect(Collectors.toList()); + + assertTrue(validatedNames.contains("Fabio Silva")); + assertFalse(validatedNames.contains("Fabio Luis Silva")); + } +} diff --git a/core-java-modules/core-java-text/pom.xml b/core-java-modules/core-java-text/pom.xml index 640b90764a..442fecd298 100644 --- a/core-java-modules/core-java-text/pom.xml +++ b/core-java-modules/core-java-text/pom.xml @@ -14,6 +14,19 @@ ../../parent-java + + + org.openjdk.jmh + jmh-core + ${jmh-core.version} + + + org.openjdk.jmh + jmh-generator-annprocess + ${jmh-core.version} + + + core-java-text diff --git a/core-java-modules/core-java-text/src/main/java/com/baeldung/patternreuse/PatternPerformanceComparison.java b/core-java-modules/core-java-text/src/main/java/com/baeldung/patternreuse/PatternPerformanceComparison.java new file mode 100644 index 0000000000..01f8df9ec6 --- /dev/null +++ b/core-java-modules/core-java-text/src/main/java/com/baeldung/patternreuse/PatternPerformanceComparison.java @@ -0,0 +1,92 @@ +package com.baeldung.patternreuse; + +import org.openjdk.jmh.annotations.*; +import org.openjdk.jmh.infra.Blackhole; +import org.openjdk.jmh.runner.RunnerException; + +import java.io.IOException; +import java.time.Instant; +import java.util.ArrayList; +import java.util.List; +import java.util.concurrent.TimeUnit; +import java.util.regex.Matcher; +import java.util.regex.Pattern; + +@BenchmarkMode(Mode.AverageTime) +@OutputTimeUnit(TimeUnit.MILLISECONDS) +@Fork(value = 1, warmups = 1) +@Warmup(iterations = 5) +@State(Scope.Benchmark) +public class PatternPerformanceComparison { + + private static final String PATTERN = "\\d*[02468]"; + private static List values; + + private static Matcher matcherFromPreCompiledPattern; + private static Pattern preCompiledPattern; + + public static void main(String[] args) throws IOException, RunnerException { + org.openjdk.jmh.Main.main(args); + } + + @Benchmark + public void matcherFromPreCompiledPatternResetMatches(Blackhole bh) { + //With pre-compiled pattern and reusing the matcher + // 1 Pattern object created + // 1 Matcher objects created + for (String value : values) { + bh.consume(matcherFromPreCompiledPattern.reset(value).matches()); + } + } + + @Benchmark + public void preCompiledPatternMatcherMatches(Blackhole bh) { + // With pre-compiled pattern + // 1 Pattern object created + // 5_000_000 Matcher objects created + for (String value : values) { + bh.consume(preCompiledPattern.matcher(value).matches()); + } + } + + @Benchmark + public void patternCompileMatcherMatches(Blackhole bh) { + // Above approach "Pattern.matches(PATTERN, value)" makes this internally + // 5_000_000 Pattern objects created + // 5_000_000 Matcher objects created + for (String value : values) { + bh.consume(Pattern.compile(PATTERN).matcher(value).matches()); + } + } + + @Benchmark + public void patternMatches(Blackhole bh) { + // Above approach "value.matches(PATTERN)" makes this internally + // 5_000_000 Pattern objects created + // 5_000_000 Matcher objects created + for (String value : values) { + bh.consume(Pattern.matches(PATTERN, value)); + } + } + + @Benchmark + public void stringMatchs(Blackhole bh) { + // 5_000_000 Pattern objects created + // 5_000_000 Matcher objects created + Instant start = Instant.now(); + for (String value : values) { + bh.consume(value.matches(PATTERN)); + } + } + + @Setup() + public void setUp() { + preCompiledPattern = Pattern.compile(PATTERN); + matcherFromPreCompiledPattern = preCompiledPattern.matcher(""); + + values = new ArrayList<>(); + for (int x = 1; x <= 5_000_000; x++) { + values.add(String.valueOf(x)); + } + } +} diff --git a/core-java-modules/core-java-text/src/test/java/com/baeldung/patternreuse/PatternUnitTest.java b/core-java-modules/core-java-text/src/test/java/com/baeldung/patternreuse/PatternUnitTest.java new file mode 100644 index 0000000000..70f5c59a95 --- /dev/null +++ b/core-java-modules/core-java-text/src/test/java/com/baeldung/patternreuse/PatternUnitTest.java @@ -0,0 +1,63 @@ +package com.baeldung.patternreuse; + +import org.junit.jupiter.api.Test; + +import java.util.Arrays; +import java.util.List; +import java.util.function.Predicate; +import java.util.regex.Matcher; +import java.util.regex.Pattern; +import java.util.stream.Collectors; +import java.util.stream.Stream; + +import static org.junit.Assert.*; + +public class PatternUnitTest { + + private static final Pattern FIRST_LAST_NAME_PRE_COMPILED_PATTERN = Pattern.compile("[a-zA-Z]{3,} [a-zA-Z]{3,}"); + private static final Pattern SPLIT_PRE_COMPILED_PATTERN = Pattern.compile("__"); + + @Test + public void givenPreCompiledPattern_whenCallMatcher_thenReturnAMatcherToMatches() { + Matcher matcherName1 = FIRST_LAST_NAME_PRE_COMPILED_PATTERN.matcher("Fabio Silva"); + Matcher matcherName2 = FIRST_LAST_NAME_PRE_COMPILED_PATTERN.matcher("Mr. Silva"); + + boolean matchesName1 = matcherName1.matches(); + boolean matchesName2 = matcherName2.matches(); + + assertTrue(matchesName1); + assertFalse(matchesName2); + } + + @Test + public void givenPreCompiledPattern_whenCallAsPredicate_thenReturnPredicateToFindThePatternInTheListElements() { + List namesToValidate = Arrays.asList("Fabio Silva", "Mr. Silva"); + Predicate patternsAsPredicate = FIRST_LAST_NAME_PRE_COMPILED_PATTERN.asPredicate(); + + List validNames = namesToValidate.stream() + .filter(patternsAsPredicate) + .collect(Collectors.toList()); + + assertEquals(1, validNames.size()); + assertTrue(validNames.contains("Fabio Silva")); + } + + @Test + public void givenPreCompiledPattern_whenCallSplit_thenReturnArrayWithValuesSplitByThePattern() { + String[] textSplit = SPLIT_PRE_COMPILED_PATTERN.split("My_Name__is__Fabio_Silva"); + + assertEquals("My_Name", textSplit[0]); + assertEquals("is", textSplit[1]); + assertEquals("Fabio_Silva", textSplit[2]); + } + + @Test + public void givenPreCompiledPattern_whenCallSplitAsStream_thenReturnArrayWithValuesSplitByThePattern() { + Stream textSplitAsStream = SPLIT_PRE_COMPILED_PATTERN.splitAsStream("My_Name__is__Fabio_Silva"); + String[] textSplit = textSplitAsStream.toArray(String[]::new); + + assertEquals("My_Name", textSplit[0]); + assertEquals("is", textSplit[1]); + assertEquals("Fabio_Silva", textSplit[2]); + } +}