BAEL-5670: Remove All Non Numeric Characters but Keep the Decimal Separator in Java String (#12827)

* BAEL-5670: Remove All Non Numeric Characters but Keep the Decimal Separator in Java String

* BAEL-5670: Remove All Non Numeric Characters but Keep the Decimal Separator in Java String

* BAEL-5670: Remove All Non Numeric Characters but Keep the Decimal Separator in Java String
- Move to a new module core-java-string-apis-2

* BAEL-5670: Add README.md file

* BAEL-5670: Add test cases to handle cases where decimal sepator is not a period or dot.

* BAEL-5670: Remove test cases to handle cases where decimal sepator is not a period or dot.

* BAEL-5670: Update ordering of modules in pom.xml

core-java-modules/core-java-string-apis-2/src/test/java/com/baeldung/removenonnumericcharacters/RemoveNonNumericCharactersAndKeepDecimalSeparatorInStringUnitTest.java

@@ -0,0 +1,46 @@
+package com.baeldung.removenonnumericcharacters;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.apache.commons.lang3.RegExUtils;
+import org.junit.jupiter.api.Test;
+
+import com.google.common.base.CharMatcher;
+
+public class RemoveNonNumericCharactersAndKeepDecimalSeparatorInStringUnitTest {
+
+    @Test
+    void givenAString_whenRemovingUsingRegexAndReplaceAllMethod_thenShouldGetExpectedResult() {
+        String s = "Testing abc123.555abc";
+        s = s.replaceAll("[^\\d.]", "");
+        assertEquals("123.555", s);
+    }
+
+    @Test
+    void givenAString_whenRemovingUsingJava8Stream_thenShouldGetExpectedResult() {
+        String s = "Testing abc123.555abc";
+        StringBuilder sb = new StringBuilder();
+        s.chars()
+          .mapToObj(c -> (char) c)
+          .filter(c -> Character.isDigit(c) || c == '.')
+          .forEach(sb::append);
+        assertEquals("123.555", sb.toString());
+    }
+
+    @Test
+    void givenAString_whenRemovingUsingGuavaLibrary_thenShouldGetExpectedResult() {
+        String s = "Testing abc123.555abc";
+        String result = CharMatcher.inRange('0', '9')
+          .or(CharMatcher.is('.'))
+          .retainFrom(s);
+        assertEquals("123.555", result);
+    }
+
+    @Test
+    void givenAString_whenRemovingUsingApacheCommonsLibrary_thenShouldGetExpectedResult() {
+        String s = "Testing abc123.555abc";
+        String result = RegExUtils.removeAll(s, "[^\\d.]");
+        assertEquals("123.555", result);
+    }
+
+}