diff --git a/postgres_java/README.md b/postgres_java/README.md
index 6c57a45..c90ee59 100644
--- a/postgres_java/README.md
+++ b/postgres_java/README.md
@@ -1,20 +1,5 @@
 # Overview
 This project shows how Postgres and Java interact.
 
-# Notes
-The instruction
-
-```/etc/init.d/postgresql status```
-
-is equivalent with
-
-```systemctl status postgresql```
-
-.
-
-obx21
-
-firstairport21
-
 # Links
 [source](https://zetcode.com/java/postgresql/)
diff --git a/postgres_java/pom.xml b/postgres_java/pom.xml
index 3027547..5aa3da5 100644
--- a/postgres_java/pom.xml
+++ b/postgres_java/pom.xml
@@ -33,12 +33,13 @@
             <!--Set up the following plugin in order to run command line applications from Maven.
             Run the app with mvn -q exec:java command.
             The q runs mvn in quite mode.-->
+            <!-- https://mvnrepository.com/artifact/org.codehaus.mojo/exec-maven-plugin -->
             <plugin>
                 <groupId>org.codehaus.mojo</groupId>
                 <artifactId>exec-maven-plugin</artifactId>
-                <version>1.6.0</version>
+                <version>3.0.0</version>
                 <configuration>
-                    <mainClass>de.swingbe.postgres_java.JavaPostgreSqlProperties
+                    <mainClass>de.swingbe.postgres_java.JavaPostgreSqlVersion
                     </mainClass>
                 </configuration>
             </plugin>
@@ -85,7 +86,7 @@
                                         implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                                     <manifestEntries>
                                         <Main-Class>
-                                            de.swingbe.postgres_java.JavaPostgreSqlProperties
+                                            de.swingbe.postgres_java.JavaPostgreSqlVersion
                                         </Main-Class>
                                     </manifestEntries>
                                 </transformer>
@@ -98,11 +99,13 @@
     </build>
 
     <dependencies>
-        <!--Add the following dependency to include PostgreSQL  Java driver.-->
+        <!--Add the following dependency to include PostgreSQL Java driver.-->
+        <!-- https://mvnrepository.com/artifact/org.postgresql/postgresql -->
         <dependency>
             <groupId>org.postgresql</groupId>
             <artifactId>postgresql</artifactId>
-            <version>42.3.1</version>
+            <version>42.3.3</version>
         </dependency>
+
     </dependencies>
 </project>
diff --git a/postgres_java/src/main/java/de/swingbe/postgres_java/JavaPostgreSqlVersion.java b/postgres_java/src/main/java/de/swingbe/postgres_java/JavaPostgreSqlVersion.java
index ff82cf8..2b1cae1 100644
--- a/postgres_java/src/main/java/de/swingbe/postgres_java/JavaPostgreSqlVersion.java
+++ b/postgres_java/src/main/java/de/swingbe/postgres_java/JavaPostgreSqlVersion.java
@@ -8,13 +8,19 @@ public class JavaPostgreSqlVersion {
 
     public static void main(String[] args) {
 
-        String url = "jdbc:postgresql://localhost:5432/testdb";
-        String user = "usr";
-        String password = "#password";
+        //connection URL
+        String url = "jdbc:postgresql://192.168.178.25:5432/testdb";
+        String user = "user";
+        String key = "key";
 
-        try (Connection con = DriverManager.getConnection(url, user, password);
-             Statement st = con.createStatement();
-             ResultSet rs = st.executeQuery("SELECT VERSION()")) {
+        try (
+                //establish connection
+                Connection con = DriverManager.getConnection(url, user, key);
+                //create object for sending SQL statements
+                Statement st = con.createStatement();
+                //execute SQL statement
+                //rs is a table of data returned by a SQL statement
+                ResultSet rs = st.executeQuery("SELECT VERSION()")) {
 
             while (rs.next()) {
                 System.out.println(rs.getString(1));