Http header in java project

[Vani Kumar]

I need to get the header value (e.g., id) from the http request in WAR project (JAX-RS project, lets call it as WAR1) and then refer or use it in another java project(so that i can use it for processing some business logic or querying database) that can be copied or deployed as jar file to the WAR1 project.

[Ulf Dittmer]

JAX-RS can inject an javax.ws.rs.core.HttpHeaders object via the @Context annotation; that provides access to the HTTP headers.

I don't understand the 2nd part of the question, but once you have the value you can use it any way you see fit.

[Vani Kumar]

Yes, with JAX-RS i can inject an javax.ws.rs.core.HttpHeaders object via the @Context annotation in Web application. Once i get it, I need to use the same value in different Java project (again the same java project will be deployed as JAR back to the web application).

[Ulf Dittmer]

That's the part I don't understand. On a server there are no "projects", only web apps. If the code is running as part of the same web app, then I don't see any issue - please elaborate if you do.

If the value is needed in some other web app then there are myriad ways of getting it there - search these forums for something like "communication between web apps" to find the many previous discussions on this topic.

[Vani Kumar]

My Java project (JAR) shouldn't have any dependency on J2EE api (like servlet, JAX-RS). The JAR project is independent of web project (WAR) but needs to be able to get http headers from web project.

I just tried to add JAX-RS library to my JAR project and checked if i can access to http header but didn't work.

[Ulf Dittmer]

Well, we don't know what you tried (I'm afraid your description is rather vague and unclear), but as long as you talk about "projects" we won't get anywhere. "Projects" are a development concept that does not exist at runtime. If the "project" results in a jar file that is then part of the same web app as the JAX-RS services, I don't see any problems for it to use whatever data the REST WS creates. Store it in a context attribute, maybe. In any case, tell us specifically what prevents you from using whatever data the WS creates in the jar file.

[Vani Kumar]

I resolved this having access the header value in the filter and save it to utility class. The value can be accessed in any project refering the utility class. I was thinking too much on this