Question

Quick project explanation: We have a built application based on JSF2 + Spring with Dynamic data sources. The data reference control is made with a spring-config:

<bean id="dataSource" class="com.xxxx.xxxx.CustomerRoutingDataSource">
....

and a class (referenced above):

public class CustomerRoutingDataSource extends AbstractRoutingDataSource {

@Override
protected Object determineCurrentLookupKey() {
    return CustomerContextHolder.getCustomerType();
}

public Logger getParentLogger() throws SQLFeatureNotSupportedException {
    return null;
}
}

the CustomerContextHolder called above is as follows:

public class CustomerContextHolder {

private static final ThreadLocal<String> contextHolder = new ThreadLocal<String>();

public static void setCustomerType(String customerType) {
    contextHolder.set(customerType);
}

public static String getCustomerType() {

    String manager = (String)FacesContext.getCurrentInstance().getExternalContext().getSessionMap().get("dataBaseManager");

    if (manager != null) {
        contextHolder.set(manager);
        FacesContext.getCurrentInstance().getExternalContext().getSessionMap().put("dataBaseManager", null);
    } else {
        String base =     (String)FacesContext.getCurrentInstance().getExternalContext().getSessionMap().get("currentDatabBase");
        if (base != null)
            contextHolder.set(base);
    }
    return (String) contextHolder.get();
}

public static void clearCustomerType() {
    contextHolder.remove();
}
}

The problem is that the last guy is calling FacesContext.getCurrentInstance() to get the servlet context. Just to explain, it uses the session Attribute dataBaseManager to tell which base it should use.
For the actual solution it was working fine, but with the implementation of a RESTEASY web service, when we make a get request the FacesContext.getCurrentInstance() is obviously returning null and crashing.

I searched a lot and could not find a way of getting the servlet-context from outside of the @GET params. I would like to know if is there any way of getting it, or if there is another solution for my dynamic datasource problem.

Thanks!

Answer 1

Like magic and probably not much people know.

I searched deep into the Resteasy documentation, and found a part of springmvc plugin that comes with the resteasy jars, that has a class called RequestUtil.class.
With that I was able to use the method getRequest() without the “@Context HttpServletRequest req” param.

Using that I was able to set the desired database on the request attributes, and from another thread (called by spring) get it and load the stuff from the right place!

I’m using it for a week now and it works like a charm. Only thing that I needed to do is change the determineLookupKey() above to this:

    @Override
protected String determineCurrentLookupKey() {
    if (FacesContext.getCurrentInstance() == null) {
        //RESTEASY
        HttpServletRequest hsr = RequestUtil.getRequest();
        String lookUpKey = (String) hsr.getAttribute("dataBaseManager");
        return lookUpKey;
    }else{
        //JSF
        return CustomerContextHolder.getCustomerType();         
    }
}

Hope this helps other people!

Thiago