Recuperar todos os nós de um Tree ( Problema de Lógica )

public String genTreeChilrenToExtjs(){
	  StringBuilder sb = new StringBuilder();
	  Object[] childs;
	  Object roots[] = model.getRoots();
	  sb.append("children:[");
	  for (int i = 0; i < roots.length; i++) {
	      MondrianMember nodeMB = (MondrianMember) roots[i];
	      
	      sb.append("{id: '").append(getIDNodeElementExtjs(roots[i])).append("',text:'")
	      		.append(nodeMB.getMonMember().getName()).append("',")
	      		.append("checked:"+getCheckedToExtjs(roots[i])+",");
	      
		  if(model.hasChildren(nodeMB)){
			  sb.append("children:[");
			  childs = model.getChildren(nodeMB);
			  for(Object ch : childs){
				 sb.append(getAllLevelsChildsToExtjs(ch));
			  }
			  sb.append("]}");
		  }else{
			  sb.append("leaf: true}");
		  }
	  }	  
	  sb.append("]");
	  sb.deleteCharAt(sb.lastIndexOf(","));
	  return sb.toString();
  }
  
  public boolean getCheckedToExtjs(Object n){
	  Element nodeElem = renderNode(null, n, 0);
	  if(nodeElem.getFirstChild().getAttributes().getNamedItem("selected") != null && 
			  !nodeElem.getFirstChild().getAttributes().getNamedItem("selected").equals("") &&
			  		nodeElem.getFirstChild().getAttributes().getNamedItem("selected").toString().contains("true")
			  ){
		  return true;
	  }else{
		  return false;
	  }
  }
  
  public String getIDNodeElementExtjs(Object n){
	  Element nodeElem = renderNode(null, n, 0);
	  return nodeElem.getAttribute("id");
  }
  
  public String getAllLevelsChildsToExtjs(Object n){
	  StringBuilder sb = new StringBuilder();
	  MondrianMember node = (MondrianMember) n;
	  
	  sb.append("{id:'").append(getIDNodeElementExtjs(n)).append("', text:'")
	  		.append(node.getMonMember().getName()).append("',")
	  		.append("checked: ").append(getCheckedToExtjs(n)+",");
	  
	  if(model.hasChildren(node)){
		  Object childs[] = model.getChildren(node);
		  if(childs.length != 0){
			  sb.append("children:[");
			  for(Object ch : childs){
				  
				  sb.append("{id: '").append(getIDNodeElementExtjs(ch)).append("', text:'")
				  		.append(((MondrianMember)ch).getMonMember().getName()).append("',")
				  		.append("checked: "+getCheckedToExtjs(ch)+",");
				  
				  if(model.hasChildren(ch)){
					  while(model.hasChildren(ch)){

						  
						  
						  // CAGADA DETECTED !!
						  // e se sempre tiverem mais e mais filhos?
						  
						  
						  
					  }
				  }else{
					  sb.append("leaf: true");
				  }
				  sb.append("}");
			  }
			  sb.append("]");
		  }else{
			  sb.append("leaf: 'true'");
		  }
	  }else{
		  sb.append("leaf: 'true'");
	  }
	  sb.append("},");
	  return sb.toString();
  }