Struts2 - Strange behavior of ModelDriven Interface

Question

My objective is to get an object of TestBean class in Struts2 Action and show its values at jsp page (view layer)

I am implementing ModelDriven interface into my action class as follows

public class TestAction extends ActionSupport implements ModelDriven<TestBean>{

    private TestBean testBeanObject;

    @Override
    public TestBean getModel() {
        return testBeanObject;
    }

    @Override
    public String execute(){

        testBeanObject = getting object of TestBean Class from business layer (It is having all the value whatever I want)

        return ActionSupport.SUCCESS;
    }
}

My TestBean class code

@Entity

@Table(name="test_bean") 
public class TestBean implements Serializable { 
private static final long serialVersionUID = 1L; 

@Id 
@Column(name="test_bean_id") 
private int testBeanId; 

private String firstProperty; 

private String secondProperty; 


@OneToMany(mappedBy="testBeanPaper", fetch = FetchType.LAZY) 
private List<PapersText> papersTexts; 

public TestBean() { 
} 

public String getFirstProperty() { 
   return this.firstProperty; 
} 

public void setFirstProperty(String firstProperty) { 
   this.firstProperty = firstProperty; 
} 

public String getSecondProperty() { 
   return this.secondProperty; 
} 

public void setSecondProperty(String secondProperty) { 
   this.secondProperty = secondProperty; 
} 

public List<PapersText> getPapersTexts() { 
   return this.papersTexts; 
} 

public void setPapersTexts(List<PapersText> papersTexts) { 
   this.papersTexts = papersTexts; 
}  

}

My jsp page code is

<s:textarea id="textarea1" class="longinput" name="firstProperty" value="%{firstProperty}"></s:textarea> 

<s:textarea id="textarea2" class="longinput" name="secondProperty" value="%{secondProperty}"></s:textarea> 

At View Layer (Jsp page) I am having text fields with same name as properties of TestBean Class.

Now the problem is

case 1.

If I am getting TestBean class object form another class (as shown above), Values are not reflecting at jsp page. Even TestBean object is initialized perfectly

case 2.

In action class, If I manually set value of properties of TestBean class like

testBeanObject.setFirstProperty("FirstProperty");
testBeanObject.setSecondProperty("SecondProperty");

It is reflecting perfectly at view layer.

I have debugged my code. It is showing that object is initialized and have correct values in both case.Then Why is it not reflecting in case 1.

Plz help