Update an object stored

Hello,

I am trying to use spring-session-data-redis:1.2.2 on an existing project built with Spring/Spring MVC.

At the moment we have java objects stored in the session, and such objects are retrieved a modified in different parts of the code. Just as a simplified example, consider the simple object:

public class TestObject implements Serializable{
    private static final long serialVersionUID = -1283966188531894027L;  
    private Integer val;
    public TestObject(Integer val){
        this.val = val;
    }

    public Integer getVal() {
        return val;
    }

    public void setVal(Integer val) {
        this.val = val;
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((val == null) ? 0 : val.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        TestObject other = (TestObject) obj;
        if (val == null) {
            if (other.val != null)
                return false;
        } else if (!val.equals(other.val))
            return false;
        return true;
    }   
}

At a certain point in the flow we retrieve the object an modify the internal value doing something like:

TestObject t = (TestObject)WebUtils.getSessionAttribute(request, "testAttribute");
t.setVal(99);

And after in the flow we retrieve it and read the value doing something like:

TestObject t = (TestObject)WebUtils.getSessionAttribute(request, "testAttribute");
int value = t.getVal();  //here we expect to see 99

Before trying to use spring-session, here value was 99.
But now when I retrieve the value, I don't see 99, but I see the original value that the TestObject had when he was initially stored in the session.

Is there something I can configure in order to be able to replicate the behaviour I had before using spring-session?

Few notes:

• redisFlushMode is configured to IMMEDIATE
• I appreciate that I could force a rewrite of the TestObject after the value is modified doing something like:

TestObject t = (TestObject)WebUtils.getSessionAttribute(request, "testAttribute");
t.setVal(99);
WebUtils.setSessionAttribute(request, "testAttribute", t);

but I was curious to know if there was something I could do without modifying the existing code.

Thanks in advance for your help.

Start by reviewing how spring-session-data-redis 1.2.2 persists session attributes and how redisFlushMode IMMEDIATE handles in-place mutations. Reproduce the example with a mutable Serializable object, then determine whether the existing behavior can be configured without resetting the attribute. Done means the behavior or limitation is confirmed and documented with a supported workaround if needed.