Java ArrayList becomes empty between two user interactions?

I'm working on an ADF fusion application with JDeveloper that runs on a Weblogic Server 12c.

The application contains a JSF page that has amongst others a fileInput, a table and a button. After the user uploads a file, it gets parsed and the results are shown in the table as intended. The next step for the user is to click on a button to save the parsed results to the DB (via backing bean).

These are the mentioned elements in the JSF-document:

<af:inputFile label="file" 
              id="if1"
              valueChangeListener="#{ResultMatching.valueChangeListener}"
              binding="#{ResultMatching.bindingInputFileCSV}"/>

<af:button text="upload" 
           id="b1"
           action="#{ResultMatching.readFile}"
           binding="#{ResultMatching.bindingButtonReadFile}"/>    

<af:table var="row" 
          rowBandingInterval="0" 
          id="t3"
          value="#{ResultMatching.Results}"
          binding="#{ResultMatching.bindingTableResults}"
          fetchSize="32" 
          width="800"                        
          partialTriggers="::b1 ::b21">
    <!--column definitions--> 
</af:table>

<af:button id="b21"
           text="save"
           action="#{ResultMatching.saveResults}"/>

These are the coherent methods in the backing bean ResultMatching.java:

private ArrayList<Result> Results= new ArrayList<Result>();
private RichTable bindingTableResults;

public void readFile() {
            
    Results.clear();
                    
    if (fileInputStream != null) {
        for (HashMap<String, String> dataSet : FileHandler.parseCFFile(fileInputStream)) {          
            Result r = new Result("values from the dataSet");
            Results.add(r);
        }
        matchResults();
    } else {
        String msg = "No file was selected for upload";
        FacesContext.getCurrentInstance().addMessage(
            null, new FacesMessage(FacesMessage.SEVERITY_INFO,msg, msg));
    }
}

private void matchResults() {
    
    //very complicated matching logic

    bindingTableResults.setValue(Results);
    AdfFacesContextImpl.getCurrentInstance().addPartialTarget(bindingTableResults);
    System.out.println(Results.size()); //prints the correct amount of results like in the file
}

public void saveResults() {
    if (Results.isEmpty()) {
        System.out.println("Results is empty!");
        return;
        //here is where I end up
        //i did no other GUI interaction meanwhile
        //neither has the getter nor setter of Results been called
        //why is it suddenly empty? Where are my objects???
    }
    for(Result r : Results){
        //as Results is empty this loop always gets skipped
        //and so does the actual update statement
    }
}

The bean is view-scoped. Any ideas where my results went? Thank you in advance!

From your code, it looks like the ResultMatching bean is in request scope:

value="#{ResultMatching.Results}"

If you want to access the bean in view scope the EL should be

value="#{viewScope.ResultMatching.Results}"

You have to change the EL for every occurrence of ResultMatching in all EL. Make sure that the bean is defined in viewScope in your task flow.