diff --git a/core-java-modules/core-java-string-operations-2/README.md b/core-java-modules/core-java-string-operations-2/README.md index 6e88eda122..8687ac19ba 100644 --- a/core-java-modules/core-java-string-operations-2/README.md +++ b/core-java-modules/core-java-string-operations-2/README.md @@ -8,5 +8,6 @@ This module contains articles about string operations. - [String Initialization in Java](https://www.baeldung.com/java-string-initialization) - [String toLowerCase and toUpperCase Methods in Java](https://www.baeldung.com/java-string-convert-case) - [Java String equalsIgnoreCase()](https://www.baeldung.com/java-string-equalsignorecase) -- [How to avoid String contains() Case Insensitive in Java](https://www.baeldung.com/how-to-avoid-string-contains-case-insensitive-in-java) +- [Case-Insensitive String Matching in Java](https://www.baeldung.com/java-case-insensitive-string-matching) +- [L-Trim and R-Trim in Java](https://www.baeldung.com/l-trim-and-r-trim-in-java) - More articles: [[<-- prev]](../core-java-string-operations) diff --git a/core-java-modules/core-java-string-operations-2/pom.xml b/core-java-modules/core-java-string-operations-2/pom.xml index b882e499b2..178edd55bc 100644 --- a/core-java-modules/core-java-string-operations-2/pom.xml +++ b/core-java-modules/core-java-string-operations-2/pom.xml @@ -109,7 +109,7 @@ 3.6.1 2.0.0.Final 3.8.1 - 27.0.1-jre + 28.2-jre 6.0.2.Final 3.0.0 2.2.6 diff --git a/core-java-modules/core-java-string-operations-2/src/main/java/com/baeldung/trim/LTrimRTrim.java b/core-java-modules/core-java-string-operations-2/src/main/java/com/baeldung/trim/LTrimRTrim.java new file mode 100644 index 0000000000..b300c783e1 --- /dev/null +++ b/core-java-modules/core-java-string-operations-2/src/main/java/com/baeldung/trim/LTrimRTrim.java @@ -0,0 +1,124 @@ +package com.baeldung.trim; + +import java.util.concurrent.TimeUnit; +import java.util.regex.Pattern; + +import org.apache.commons.lang3.StringUtils; +import org.openjdk.jmh.annotations.Benchmark; +import org.openjdk.jmh.annotations.BenchmarkMode; +import org.openjdk.jmh.annotations.Fork; +import org.openjdk.jmh.annotations.Mode; +import org.openjdk.jmh.annotations.OutputTimeUnit; +import org.openjdk.jmh.annotations.Scope; +import org.openjdk.jmh.annotations.Setup; +import org.openjdk.jmh.annotations.State; + +import com.google.common.base.CharMatcher; + +/** + * Based on https://github.com/tedyoung/indexof-contains-benchmark + */ +@Fork(5) +@State(Scope.Benchmark) +@BenchmarkMode(Mode.AverageTime) +@OutputTimeUnit(TimeUnit.NANOSECONDS) +public class LTrimRTrim { + + private String src; + private static String ltrimResult; + private static String rtrimResult; + private static Pattern LTRIM = Pattern.compile("^\\s+"); + private static Pattern RTRIM = Pattern.compile("\\s+$"); + + public static void main(String[] args) throws Exception { + org.openjdk.jmh.Main.main(args); + } + + @Setup + public void setup() { + src = " White spaces left and right "; + ltrimResult = "White spaces left and right "; + rtrimResult = " White spaces left and right"; + } + + public static String whileLtrim(String s) { + int i = 0; + while (i < s.length() && Character.isWhitespace(s.charAt(i))) { + i++; + } + return s.substring(i); + } + + public static String whileRtrim(String s) { + int i = s.length() - 1; + while (i >= 0 && Character.isWhitespace(s.charAt(i))) { + i--; + } + return s.substring(0, i + 1); + } + + private static boolean checkStrings(String ltrim, String rtrim) { + boolean result = false; + + if (ltrimResult.equalsIgnoreCase(ltrim) && rtrimResult.equalsIgnoreCase(rtrim)) + result = true; + + return result; + } + + // Going through the String detecting Whitespaces + @Benchmark + public boolean whileCharacters() { + String ltrim = whileLtrim(src); + String rtrim = whileRtrim(src); + + return checkStrings(ltrim, rtrim); + } + + // replaceAll() and Regular Expressions + @Benchmark + public boolean replaceAllRegularExpression() { + String ltrim = src.replaceAll("^\\s+", ""); + String rtrim = src.replaceAll("\\s+$", ""); + + return checkStrings(ltrim, rtrim); + } + + public static String patternLtrim(String s) { + return LTRIM.matcher(s) + .replaceAll(""); + } + + public static String patternRtrim(String s) { + return RTRIM.matcher(s) + .replaceAll(""); + } + + // Pattern matches() with replaceAll + @Benchmark + public boolean patternMatchesLTtrimRTrim() { + String ltrim = patternLtrim(src); + String rtrim = patternRtrim(src); + + return checkStrings(ltrim, rtrim); + } + + // Guava CharMatcher trimLeadingFrom / trimTrailingFrom + @Benchmark + public boolean guavaCharMatcher() { + String ltrim = CharMatcher.whitespace().trimLeadingFrom(src); + String rtrim = CharMatcher.whitespace().trimTrailingFrom(src); + + return checkStrings(ltrim, rtrim); + } + + // Apache Commons StringUtils containsIgnoreCase + @Benchmark + public boolean apacheCommonsStringUtils() { + String ltrim = StringUtils.stripStart(src, null); + String rtrim = StringUtils.stripEnd(src, null); + + return checkStrings(ltrim, rtrim); + } + +} diff --git a/core-java-modules/core-java-string-operations-2/src/test/java/com/baeldung/trim/LTrimRTrimUnitTest.java b/core-java-modules/core-java-string-operations-2/src/test/java/com/baeldung/trim/LTrimRTrimUnitTest.java new file mode 100644 index 0000000000..78bf01e540 --- /dev/null +++ b/core-java-modules/core-java-string-operations-2/src/test/java/com/baeldung/trim/LTrimRTrimUnitTest.java @@ -0,0 +1,78 @@ +package com.baeldung.trim; + +import org.apache.commons.lang3.StringUtils; +import org.junit.Assert; +import org.junit.Test; + +import com.google.common.base.CharMatcher; + +import java.util.regex.Pattern; + +/** + * BAEL-3755: LTrim and RTrim examples. + */ +public class LTrimRTrimUnitTest { + + private String src = " White spaces left and right "; + private final static String ltrimResult = "White spaces left and right "; + private final static String rtrimResult = " White spaces left and right"; + + @Test + public void givenString_whenCallingWhileCharacters_thenReturnsTrue() { + String ltrim = LTrimRTrim.whileLtrim(src); + String rtrim = LTrimRTrim.whileRtrim(src); + + // Compare the Strings obtained and the expected + Assert.assertTrue(ltrimResult.equalsIgnoreCase(ltrim)); + + Assert.assertTrue(rtrimResult.equalsIgnoreCase(rtrim)); + } + + @Test + public void givenString_whenCallingContainsWithReplaceAll_shouldReturnTrue() { + // Use replaceAll with Regular Expressions + String ltrim = src.replaceAll("^\\s+", ""); + String rtrim = src.replaceAll("\\s+$", ""); + + // Compare the Strings obtained and the expected + Assert.assertTrue(ltrimResult.equalsIgnoreCase(ltrim)); + + Assert.assertTrue(rtrimResult.equalsIgnoreCase(rtrim)); + } + + @Test + public void givenString_whenCallingPaternCompileMatcherReplaceAll_thenReturnsTrue() { + // Use Pattern Compile Matcher and Find to avoid case insensitive issues + String ltrim = LTrimRTrim.patternLtrim(src); + String rtrim = LTrimRTrim.patternRtrim(src); + + // Compare the Strings obtained and the expected + Assert.assertTrue(ltrimResult.equalsIgnoreCase(ltrim)); + + Assert.assertTrue(rtrimResult.equalsIgnoreCase(rtrim)); + } + + @Test + public void givenString_whenCallingGuavaCharMatcher_thenReturnsTrue() { + // Use StringUtils containsIgnoreCase to avoid case insensitive issues + String ltrim = CharMatcher.whitespace().trimLeadingFrom(src);; + String rtrim = CharMatcher.whitespace().trimTrailingFrom(src); + + // Compare the Strings obtained and the expected + Assert.assertTrue(ltrimResult.equalsIgnoreCase(ltrim)); + + Assert.assertTrue(rtrimResult.equalsIgnoreCase(rtrim)); + } + + @Test + public void givenString_whenCallingStringUtilsStripStartEnd_thenReturnsTrue() { + // Use StringUtils containsIgnoreCase to avoid case insensitive issues + String ltrim = StringUtils.stripStart(src, null); + String rtrim = StringUtils.stripEnd(src, null); + + // Compare the Strings obtained and the expected + Assert.assertTrue(ltrimResult.equalsIgnoreCase(ltrim)); + Assert.assertTrue(rtrimResult.equalsIgnoreCase(rtrim)); + } + +}