Adding files for BAEL-2196 (#6477)

* Adding files for BAEL-2196

* modified Package structure

maven/compiler-plugin-java-9/pom.xml

@@ -0,0 +1,22 @@
+<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>
+	<groupId>com.baeldung</groupId>
+	<artifactId>compiler-plugin-java-9</artifactId>
+	<version>0.0.1-SNAPSHOT</version>
+	
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-compiler-plugin</artifactId>
+				<version>3.8.0</version>
+				<configuration>
+					<source>9</source>
+					<target>9</target>
+				</configuration>
+			</plugin>
+		</plugins>
+	</build>
+</project>

maven/compiler-plugin-java-9/src/main/java/com/baeldung/maven/java9/MavenCompilerPlugin.java

@@ -0,0 +1,9 @@
+package com.baeldung.maven.java9;
+
+import static javax.xml.XMLConstants.XML_NS_PREFIX;
+
+public class MavenCompilerPlugin {
+    public static void main(String[] args) {
+        System.out.println("The XML namespace prefix is: " + XML_NS_PREFIX);
+    }
+}

maven/compiler-plugin-java-9/src/main/java/module-info.java

@@ -0,0 +1,3 @@
+module com.baeldung.maven.java9 {
+    requires java.xml;
+}