Struts2 POJO population from URL

[James Jithin]

I have a Java Object with many other nested Objects and lists of Objects. When the request arrives from the client, I see that the Object is populated only to a few levels. Is there any configuration that sets this is Struts 2? Here is my example.

class MyActionClass extends ActionSupport {
    	private Abc abc;
    	public Abc getAbc() {
    		return abc;
    	}
    	public void setAbc(Abc abc) {
    		this.abc = abc;
    	}
    	public String populate() {
    		MyService myService = new MyService();
    		abc = myService.getMyAbc();
    		return SUCCESS;
    	}
    	public String update() {
    		MyService myService = new MyService();
    		myService.updateAbc(abc);
    		return SUCCESS;
    	}
    }
    
    class Abc {
    	private List<Def> defList;
    	private Ghi ghi;
    	public void setDefList(List<Def> defList) {
    		this.defList = defList;
    	}
    	public List<Def> getDefList(){
    		return defList;
    	}
    	public void setGhi(Ghi ghi) {
    		this.ghi = ghi;
    	}
    	public Ghi getGhi() {
    		return ghi;
    	}
    }
    
    class Def {
    	private String name;
    	private long id;
    	public String getName() {
    		return name;
    	}
    	public void setName(String name) {
    		this.name = name;
    	}
    	public long getId() {
    		return id;
    	}
    	public void setId(long id) {
    		this.id = id;
    	}
    }
    
    class Ghi {
    	private List<Def> defList;
    	private String ghiName;
    	
    	public void setDefList(List<Def> defList) {
    		this.defList = defList;
    	}
    	public List<Def> getDefList() {
    		return defList;
    	}
    	public void setGhiName(String ghiName) {
    		this.ghiName = ghiName;
    	}
    	public String getGhiName() {
    		return ghiName;
    	}
    }

When I call the `populate` method and when send to the jsp, the iteration happens good with all the elements. But, when I try to update, i.e. when then form is submitted, the `update()` method is called, but the instance variable abc does not get populated completely.

I have seen the url which is passed and everything seems to be fine. Let me tell you what happens. The url will be something like (splitting with line break for easy understanding here),

&abc.defList[0].name=alex &abc.defList[0].id=1 &abc.defList[1].name=bobby &abc.defList[1].id=2 &abc.ghi.ghiName=GHINAME &abc.ghi.defList[0].name=Jack &abc.ghi.defList[0].id=1 &abc.ghi.defList[1].name=Jill &abc.ghi.defList[1].id=2

In this case, the `defList` inside `abc` and `ghi.ghiName` in `abc` are populated with no issues. But the `defList` of `abc.ghi` is not populated. Is this a common behavior of Struts 2? Is there any means by which this can be overridden?

[Mohana Rao Sv]

Use preperable interface and override prepare method in your action class. And add it to interceptors. This interceptor is very useful for any situation where you need to ensure some logic runs before the actual execute method runs.