loginmodules/password/authenticators/jdbc/src/main/java/org/beiter/michael/authn/jaas/loginmodules/password/authenticators/jdbc/propsbuilder/JaasBasedConnPropsBuilder.java
private static void copyValue(final Map<String, ?> sourceMap, final String sourceKey,
                                  final Map<String, String> targetMap, final String targetKey) {

        if (getOption(sourceKey, sourceMap) != null && String.class.isInstance(getOption(sourceKey, sourceMap))) {
            targetMap.put(targetKey, (String) getOption(sourceKey, sourceMap));
        }
    }
private static void copyValue(final Map<String, ?> sourceMap, final String sourceKey,
                                  final Map<String, String> targetMap, final String targetKey) {

        if (getOption(sourceKey, sourceMap) != null && String.class.isInstance(getOption(sourceKey, sourceMap))) {
            targetMap.put(targetKey, (String) getOption(sourceKey, sourceMap));
        }
    }
Copy the value of a specific key in a source map to a specific key in a target map.
<p>
The method checks if the value assigned to the source key is <code>null</code>, and does not copy it if it is
<code>null</code>.

@param sourceMap The source map to copy from
@param sourceKey The source key to copy from
@param targetMap The target map to copy to
@param targetKey The target key to copy to