Question

I’m using a for loop to iterate over persisted form objects on validation and then compare against non persisted form objects. I’m using .contains in the loop, however the first loop returns true and every other loop returns false even though the pr object doesn’t contain the prPersist object. Could someone tell me what I’m doing wrong, or if there is a better way to handle this? Thanks

Hibernate Entity

PurchaseRequest Object

    @OneToMany(mappedBy = "purchaseRequest", cascade=CascadeType.ALL, orphanRemoval=true)

public List<LineItem> getLineItems() {
    if(lineItems == null ){
        lineItems = new ArrayList<LineItem>();
    }
    return lineItems;
}

public void setLineItems(List<LineItem> lineItems) {
    this.lineItems = lineItems;
}

LineItem Object

@ManyToOne
@JoinColumn(name = "pr_id", nullable = false)
private PurchaseRequest purchaseRequest;

public PurchaseRequest getPurchaseRequest() {
    return purchaseRequest;
}

public void setPurchaseRequest(PurchaseRequest purchaseRequest) {
    this.purchaseRequest = purchaseRequest;
}

Page Class

    private List<LineItem> lineItems;

    private PurchaseRequest pr;

    @Persist
    private PurchaseRequest prPersist;

    System.out.println("prPersist size " + prPersist != null ? prPersist.getLineItems().size() : "");
    System.out.println("pr size outer loop " + pr.getLineItems().size());
    if(prPersist != null) {
        for(LineItem _lineItem : prPersist.getLineItems()) {
            System.out.println("pr lineItem object value " + _lineItem.getQuantity());
            System.out.println("pr lineItem size inner loop " + pr.getLineItems().size());
            System.out.println("pr lineItem contains prPersist lineItem " + pr.getLineItems().contains(_lineItem));
            if(!pr.getLineItems().contains(_lineItem)) {
                _lineItem.setPurchaseRequest(pr);
                pr.getLineItems().add(_lineItem);
                System.out.println("new line item added");
            }
        }
        prPersist = null;
    }

Printout results

prPersist size 2
pr size outer loop 0
pr lineItem object value 4
pr lineItem size inner loop 0
pr lineItem contains prPersist lineItem false
new line item added
pr lineItem object value 5
pr lineItem size inner loop 1
pr lineItem contains prPersist lineItem true

Setting prPersist

void onValidate() {
    prPersist = null;

    if (form.getHasErrors()) {
        prPersist = pr;            
    }
}

Answer 1

Given that prPersist and ‘pr’ are different instances I’m guessing the LineItems each contains can be different instances?

If so, I’d guess you’ve got a problem with you implementation of the equals method on LineItem.