How to get a Resource object when we have node path?

In Java:
@Reference
private ResourceResolverFactory resourceResolverFactory;
ResourceResolver resolver=null;
resolver = resourceResolverFactory.getAdministrativeResourceResolver(null);
Resource res=null;
res= resolver.getResource("PATH");

In JSP:
Resource res= resourceResolver.getResource("PATH");

How to get a Node, Get node property, Add/Update node property:
Node node = res.adaptTo(Node.class);

Get property:
String prop= node.getProperty("Prop_name").getValue().getString();
String prop = node.setProperty("Prop_name","Value");
Note: Don't forget to save the session when the node is updated.

Update Node using PersistableValueMap:
Resource resource = resolver.getResource("Node Path");
if(resource !=null)
{
PersistableValueMap valueMap= resource.adaptTo(PersistableValueMap.class);
valueMap.put("propname","value");
valueMap.save();
}

How to get a JackRabbit session in the Workflow:
final JackrabbitSession jackrabbitSession = (JackrabbitSession) wfsession.getSession();
UserManager userManager = jackrabbitSession.getUserManager();