Question

I'm trying to sort a Hazelcast IList using following code

Class PaymentChannelEntry

public class PaymentChannelEntry implements Serializable {

    private static final long serialVersionUID = 5416475057971472127L;
    private Long executionTimestamp; // timestamp of the time of the transaction in Zulu time zone (UTC)
    private BigDecimal transactionAmount; // The amount of the transaction that contributes to the associated payment channel

    public PaymentChannelEntry(Long executionTimestamp, BigDecimal transactionAmount) {
        this.executionTimestamp = executionTimestamp;
        this.transactionAmount = transactionAmount;
    }

    public Long getExecutionTimestamp() {
        return executionTimestamp;
    }

    public void setExecutionTimestamp(Long executionTimestamp) {
        this.executionTimestamp = executionTimestamp;
    }

    public BigDecimal getTransactionAmount() {
        return transactionAmount;
    }

    public void setTransactionAmount(BigDecimal transactionAmount) {
        this.transactionAmount = transactionAmount;
    }
}

Then I select list of PaymentChannelEntry from Hazelcast IList

IList<PaymentChannelEntry> entryIList = channelStore.getChannelEntryList(channelData.getType())

Then when I use sort method, it throws exception:

java.lang.UnsupportedOperationException
    at com.hazelcast.util.UnmodifiableListIterator.set(UnmodifiableListIterator.java:30)
    at java.util.List.sort(List.java:482)

Any solution will be appreciated.

Thanks.

Answer 1

It seems like the list returned by channelStore.getChannelEntryList is not modifiable hence the exception.

if you cannot modify what's being returned then first make a copy then sort:

// example
IList<PaymentChannelEntry> result = new ArrayList<>(channelStore.getChannelEntryList(channelData.getType()));    
// now sort the list

The above is just an example and might not compile but ultimately you'll need to copy whatever is returned from channelStore.getChannelEntryList(channelData.getType()) into a mutable list and then sort it.

Hazelcast unable to sort IList

1 个答案: