Java UnsupportedOperationException与Collection对象

我在JDK 1.7中使用Java集合时出错:
我在此行中收到此异常: proposalStatuses.addAll(getAllSubmittedStatuses())

java.lang.UnsupportedOperationException
        at java.util.AbstractList.add(Unknown Source)
        at java.util.AbstractList.add(Unknown Source)
        at java.util.AbstractCollection.addAll(Unknown Source)

试图将集合添加到列表中

/**
     * Gets the all submitted statuses.
     *
     * @return the all submitted statuses
     */
    private Collection<ProposalStatus> getAllSubmittedStatuses() {

        return Arrays.asList(
                  ProposalStatus.SAVED_TO_IOS
                , ProposalStatus.SENDED_TO_IOS_IN_PROGRESS
                );
    }

    /**
     * Gets the all received statuses.
     *
     * @return the all received statuses
     */
    private Collection<ProposalStatus> getAllReceivedStatuses() {

        Collection<ProposalStatus> proposalStatuses =

                Arrays.asList(
                  ProposalStatus.RECEIVED_BY_IOS
                , ProposalStatus.SUBMITTED_TO_IOS
                , ProposalStatus.RECEIVED_IOS
                );

        proposalStatuses.addAll(getAllSubmittedStatuses());

        return proposalStatuses;
    }

最佳答案

从javadoc of Arrays.asList() (重点是我):



简而言之:您无法从此类列表中获取.add*()或.remove*()!您将不得不使用另一个可修改的List实现(例如ArrayList)。