BAEL-2832: new java-strings-2 project, with tests and benchmar

java-strings-2/src/test/java/com/baeldung/string/search/SubstringSearch.java

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+package com.baeldung.string.search;
+
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import org.apache.commons.lang3.StringUtils;
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * BAEL-2832: Different ways to check if a Substring could be found in a String.
+ */
+public class SubstringSearch {
+
+    @Test
+    public void searchSubstringWithIndexOf() {
+        Assert.assertEquals(9, "Bohemian Rhapsodyan".indexOf("Rhap"));
+
+        // indexOf will return -1, because it's case sensitive
+        Assert.assertEquals(-1, "Bohemian Rhapsodyan".indexOf("rhap"));
+
+        // indexOf will return 9, because it's all lowercase
+        Assert.assertEquals(9, "Bohemian Rhapsodyan".toLowerCase()
+            .indexOf("rhap"));
+
+        // it will return 6, because it's the first occurrence. Sorry Queen for being blasphemic
+        Assert.assertEquals(6, "Bohemian Rhapsodyan".indexOf("an"));
+    }
+
+    @Test
+    public void searchSubstringWithContains() {
+        Assert.assertTrue("Hey Ho, let's go".contains("Hey"));
+
+        // contains will return false, because it's case sensitive
+        Assert.assertFalse("Hey Ho, let's go".contains("hey"));
+
+        // contains will return true, because it's all lowercase
+        Assert.assertTrue("Hey Ho, let's go".toLowerCase().contains("hey"));
+
+        // contains will return false, because 'jey' can't be found
+        Assert.assertFalse("Hey Ho, let's go".contains("jey"));
+    }
+
+    @Test
+    public void searchSubstringWithStringUtils() {
+        Assert.assertTrue(StringUtils.containsIgnoreCase("Runaway train", "train"));
+
+        // it will also be true, because ignores case ;)
+        Assert.assertTrue(StringUtils.containsIgnoreCase("Runaway train", "Train"));
+    }
+
+    @Test
+    public void searchUsingPattern() {
+
+        // We create the Pattern first
+        Pattern pattern = Pattern.compile("(?<!\\S)" + "road" + "(?!\\S)");
+
+        // We need to create the Matcher after
+        Matcher matcher = pattern.matcher("Hit the road Jack");
+
+        // find will return true when the first match is found
+        Assert.assertTrue(matcher.find());
+
+        // We will create a different matcher with a different text
+        matcher = pattern.matcher("and don't you come back no more");
+
+        // find will return false, because 'road' can't be find as a substring
+        Assert.assertFalse(matcher.find());
+    }
+}

java-strings-2/src/test/resources/.gitignore

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+*.class
+
+#folders#
+/target
+/neoDb*
+/data
+/src/main/webapp/WEB-INF/classes
+*/META-INF/*
+
+# Packaged files #
+*.jar
+*.war
+*.ear