如何在Java（fx）中释放静态ObservableList

Question

I am using a static observable list for a tableview in a javafx application.

  public class TableData {
          private static ObservableList<MyObject> data = FXCollections.observableArrayList();

          public static ObservableList<MyObject> getData(){
                 return data;
          }
  }

When I load new Data I tried several approaches to remove the “old“ data to release memory, like

    TableData.getData().clear();

or

    TableData.getData() = FXCollections.observableArrayList();

or even

     for(int i=0; i< TableData.getData().size(); i++){
           MyObject mo = TableData.getData().get(i);
           mo=null;
     }

But still no Memory is released (checked with netbeans Analyzer)

Can anyboy help?

Answer 1

Your problem is not related to JavaFX. In general you should learn how references are handled in java. You can find an introduction here or here .

Code like in your example ( TableData.getData() = FXCollections.observableArrayList(); ) do not change the internals of your static collection. Next to this defining something like this as a static value is an anti pattern.

Based on your question and sample I assume that you are quite new to the Java language. I prefer to read a general Java book (see this link for a good overview). This will help you to understand the general problems in your sample.

In general you have the same behaviour in mostly all object orientated languages so even a book / tutorial about OOD might be a good idea :)