CODEWITHSUNDEEP
java
Murali
Murali

Reputation: 378

How to get all child of a parent and their children using recursion

refference.

Here I want to get all the children of a parent. This is my Screen.

In This screen I want to save all the rows. For that I have created the following beans.

public class AdminComponentBean{

    List<MultiAdminComponent> componentListbean;
}

Another Bean:-

public class MultiAdminComponent {

    private String componentName;
    private String componentIdentification;
    private String componentType;
    private String componentState;
    private String componentUrl;
    private String rowId;
    private List<MultiAdminComponent> items;
    }

In my service I try to retrieve all the children. But I am not able to get children of the parent.

  List < MultiAdminComponent > adminComponentList = adminComponentBean.getComponentListbean();
       for (MultiAdminComponent adminComponentListBean: adminComponentList) {

          flag = BaseDAO.getAdminComponentDAOObject().saveParentComponentDetails(adminComponentListBean);//Here the parents will save but not the childs
          for (MultiAdminComponent adminComponentchild: adminComponentListBean.getItems()) {//here I am trying to save childs

          }
 }

Upvotes: 0

Views: 4215

Answers (1)

Darshan Mehta
Darshan Mehta

Reputation: 30809

You can write a recursive method like this:

void addChildren(MultiAdminComponent parent, List<MultiAdminComponent> children) {
    if(null != parent.getItems()) {
        for(MultiAdminComponent child : parent.getItems()) {
            children.add(child);
            addChildren(child, children);
        }
    }
}

And call it with an empty list, e.g.:

MultiAdminComponent parent; //parent
List<MultiAdminComponent> children = new ArrayList<>();
addChildren(parent, children);

After the method call, children list should have all the child objects.

Upvotes: 3

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