package com.baeldung.string; import org.apache.commons.lang3.StringUtils; import org.junit.Test; import static org.junit.Assert.assertFalse; import static org.junit.Assert.assertTrue; public class StringReplaceAndRemoveUnitTest { @Test public void givenTestStrings_whenReplace_thenProcessedString() { String master = "Hello World Baeldung!"; String target = "Baeldung"; String replacement = "Java"; String processed = master.replace(target, replacement); assertTrue(processed.contains(replacement)); assertFalse(processed.contains(target)); } @Test public void givenTestStrings_whenReplaceAll_thenProcessedString() { String master2 = "Welcome to Baeldung, Hello World Baeldung"; String regexTarget= "(Baeldung)$"; String replacement = "Java"; String processed2 = master2.replaceAll(regexTarget, replacement); assertTrue(processed2.endsWith("Java")); } @Test public void givenTestStrings_whenStringBuilderMethods_thenProcessedString() { String master = "Hello World Baeldung!"; String target = "Baeldung"; String replacement = "Java"; int startIndex = master.indexOf(target); int stopIndex = startIndex + target.length(); StringBuilder builder = new StringBuilder(master); builder.delete(startIndex, stopIndex); assertFalse(builder.toString().contains(target)); builder.replace(startIndex, stopIndex, replacement); assertTrue(builder.toString().contains(replacement)); } @Test public void givenTestStrings_whenStringUtilsMethods_thenProcessedStrings() { String master = "Hello World Baeldung!"; String target = "Baeldung"; String replacement = "Java"; String processed = StringUtils.replace(master, target, replacement); assertTrue(processed.contains(replacement)); String master2 = "Hello World Baeldung!"; String target2 = "baeldung"; String processed2 = StringUtils.replaceIgnoreCase(master2, target2, replacement); assertFalse(processed2.contains(target)); } }