Postgres JDBC maven dependency not found

What exactly do you have in your pom.xml file?

Should be something like:

<!-- https://mvnrepository.com/artifact/org.postgresql/postgresql -->
<dependency>
    <groupId>org.postgresql</groupId>
    <artifactId>postgresql</artifactId>
    <version>9.4.1212</version>
</dependency>

Make sure you're using org.postgresql as the groupId, instead of postgresql.

Should be:

<dependency>
    <groupId>org.postgresql</groupId>
    <artifactId>postgresql</artifactId>
</dependency>

Do not put the version. Let Maven does that itself