BAEL-1818 - A Guide to Connection Pools in Java (#4735)

* Strange git issue with README.MD, wouldn't revert the file

* Initial Commit

* Initial Commit

* Update pom.xml

* Update pom.xml

* Initial Commit

* Update pom.xml

* Update source files

* Update source files

* Update source files

* Update source files

* Update Application.java

* Update pom.xml

* Update HikariCPDataSourceUnitTest class

* Update HikariCPDataSourceUnitTest.java

* Update pom.xml

* Update unit test classes

* Update BasicConnectionPoolUnitTest.java

* Fix indentation in DBCDDataSource class

* Update DBCPDataSource.java

* Update BasicConnectionPool class

* Update BasicConnectionPool class

* Update BasicConnectionPool.java

* Update BasicConnectionPool.java

* Update pom.xml

* Update pom.xml

* BAEL-1818 Refactored getConnection(), added shutdown(), cleaned up pom.xml

* BAEL-1818 Removed getConnectionPool(), upgraded c3po version

* BAEL-1818 Deleted obsolete connectionpool module

* BAEL-1818 Deleted obsolete connectionpool module

core-java/pom.xml

@@ -1,5 +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">
+         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>core-java</artifactId>
@@ -73,9 +73,10 @@
         <dependency>
             <groupId>org.assertj</groupId>
             <artifactId>assertj-core</artifactId>
-            <version>${assertj.version}</version>
+            <version>${assertj-core.version}</version>
             <scope>test</scope>
         </dependency>
+
         <dependency>
             <groupId>commons-codec</groupId>
             <artifactId>commons-codec</artifactId>
@@ -146,6 +147,21 @@
             <artifactId>icu4j</artifactId>
             <version>${icu4j.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-dbcp2</artifactId>
+            <version>${commons-dbcp2.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.zaxxer</groupId>
+            <artifactId>HikariCP</artifactId>
+            <version>${HikariCP.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.mchange</groupId>
+            <artifactId>c3p0</artifactId>
+            <version>${c3p0.version}</version>
+        </dependency>
     </dependencies>
 
     <build>
@@ -301,7 +317,7 @@
                     </arguments>
                 </configuration>
             </plugin>
-
+            
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-javadoc-plugin</artifactId>
@@ -348,6 +364,7 @@
                     <plugin>
                         <groupId>org.codehaus.mojo</groupId>
                         <artifactId>exec-maven-plugin</artifactId>
+                        <version>${exec-maven-plugin.version}</version>
                         <executions>
                             <execution>
                                 <id>run-benchmarks</id>
@@ -375,6 +392,7 @@
     </profiles>
 
     <properties>
+        
         <!-- marshalling -->
         <jackson.version>2.8.5</jackson.version>
         <gson.version>2.8.2</gson.version>
@@ -395,16 +413,23 @@
         <vavr.version>0.9.0</vavr.version>
 
         <!-- testing -->
-        <assertj.version>3.6.1</assertj.version>
+        <assertj-core.version>3.10.0</assertj-core.version>
 
+        <!-- JDBC pooling frameworks -->
+        <commons-dbcp2.version>2.4.0</commons-dbcp2.version>
+        <HikariCP.version>3.2.0</HikariCP.version>
+        <c3p0.version>0.9.5.2</c3p0.version>
+        
         <!-- maven plugins -->
         <maven-surefire-plugin.version>2.19.1</maven-surefire-plugin.version>
         <springframework.spring-web.version>4.3.4.RELEASE</springframework.spring-web.version>
         <springframework.boot.spring-boot-starter.version>1.5.8.RELEASE</springframework.boot.spring-boot-starter.version>
+        
         <javamoney.moneta.version>1.1</javamoney.moneta.version>
         <h2database.version>1.4.197</h2database.version>
         <esapi.version>2.1.0.1</esapi.version>
         <jmh-core.version>1.19</jmh-core.version>
+       
         <jmh-generator-annprocess.version>1.19</jmh-generator-annprocess.version>
         <maven-javadoc-plugin.version>3.0.0-M1</maven-javadoc-plugin.version>
         <javax.mail.version>1.5.0-b01</javax.mail.version>
@@ -412,7 +437,8 @@
         <onejar-maven-plugin.version>1.4.4</onejar-maven-plugin.version>
         <maven-shade-plugin.version>3.1.1</maven-shade-plugin.version>
         <spring-boot-maven-plugin.version>2.0.3.RELEASE</spring-boot-maven-plugin.version>
+        <exec-maven-plugin.version>1.6.0</exec-maven-plugin.version>
         <icu4j.version>61.1</icu4j.version>
     </properties>
 
-</project>
+</project>