BAEL-5246: pom cleanup (#4620)

* BAEL-5246: round 1 of pom cleanup - upto "jersey" project

* BAEL-5246: Initial pass for pom cleanup - upto spring-cloud

* BAEL-5246: pom cleanup upto testing-modules/junit5

* BAEL-5246: pom cleanup - upto xstream

* BAEL-5246: pom cleanup - last round (before review)

out/production/main180/com/baeldung/javaeeannotations/JavaEEAnnotationsSample/pom.xml

@@ -1,4 +1,5 @@
-<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">
+<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.javaeeannotations</groupId>
     <artifactId>JavaEEAnnotationsSample</artifactId>
@@ -12,29 +13,30 @@
         <dependency>
             <groupId>javax.annotation</groupId>
             <artifactId>javax.annotation-api</artifactId>
-            <version>1.3</version>
+            <version>${annotation-api.version}</version>
         </dependency>
 
         <dependency>
             <groupId>javax.servlet</groupId>
             <artifactId>javax.servlet-api</artifactId>
-            <version>3.1.0</version>
+            <version>${servlet.version}</version>
         </dependency>
 
         <dependency>
             <groupId>javax.servlet.jsp</groupId>
             <artifactId>jsp-api</artifactId>
-            <version>2.1</version>
+            <version>${jsp.version}</version>
         </dependency>
 
     </dependencies>
+
     <build>
         <pluginManagement>
             <plugins>
                 <plugin>
                     <groupId>org.apache.maven.plugins</groupId>
                     <artifactId>maven-war-plugin</artifactId>
-                    <version>2.4</version>
+                    <version>${maven-war-plugin.version}</version>
                     <configuration>
                         <warSourceDirectory>src/main/webapp</warSourceDirectory>
                         <warName>SpringFieldConstructorInjection</warName>
@@ -45,4 +47,11 @@
         </pluginManagement>
         <finalName>JavaEEAnnotationsSample</finalName>
     </build>
+    
+    <properties>
+        <annotation-api.version>1.3</annotation-api.version>
+        <servlet.version>3.1.0</servlet.version>
+        <jsp.version>2.1</jsp.version>
+        <maven-war-plugin.version>2.4</maven-war-plugin.version>
+    </properties>
 </project>