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/README.md

@@ -0,0 +1,5 @@
+## Java String APIs
+
+This module contains articles about string APIs.
+
+### Relevant Articles:

core-java-modules/core-java-string-apis-2/pom.xml

@@ -0,0 +1,44 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>core-java-string-apis-2</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <name>core-java-string-apis-2</name>
+    <packaging>jar</packaging>
+
+    <parent>
+        <groupId>com.baeldung.core-java-modules</groupId>
+        <artifactId>core-java-modules</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>com.google.guava</groupId>
+            <artifactId>guava</artifactId>
+            <version>${guava.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-lang3</artifactId>
+            <version>${commons.lang3.version}</version>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <finalName>core-java-string-apis-2</finalName>
+        <resources>
+            <resource>
+                <directory>src/main/resources</directory>
+                <filtering>true</filtering>
+            </resource>
+        </resources>
+    </build>
+
+    <properties>
+        <commons.lang3.version>3.12.0</commons.lang3.version>
+        <guava.version>31.1-jre</guava.version>
+    </properties>
+</project>

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);
+    }
+
+}

core-java-modules/pom.xml

@@ -121,6 +121,7 @@
         <module>core-java-string-algorithms</module>
         <module>core-java-string-algorithms-2</module>
         <module>core-java-string-apis</module>
+        <module>core-java-string-apis-2</module>
         <module>core-java-string-conversions</module>
         <module>core-java-string-conversions-2</module>
         <module>core-java-string-operations</module>