Servlet编译错误与Comparator接口

Question

在使用Netbeans和Weblogic 12c从Java 1.7升级到Java 1.8之后，我们在Comparator接口上收到了servlet编译错误。 Java 1.7中的.jsp文件运行正常。我已阅读其他类似问题，但尚未找到解决方案。我已经尝试检查Weblogic Domain配置JSP Compiler Backwards Compatible但没有成功。编译器抱怨的方法是default方法，所以不需要提及它们，对吗？是否需要为Java 8重写实现Comparator的类？如果是这样，请指教。

错误

 viewFundCites.jsp:151:11: The type compareFundedPrOrderedByPr must implement the inherited abstract method Comparator.thenComparing(Function, Comparator)
    class compareFundedPrOrderedByPr implements Comparator {
          ^-----------------------^

代码

class compareFundedPrOrderedByPr implements Comparator {
    public int compare (Object a, Object b) {
        int ordering = 0;
        FundCite itemA = (FundCite)a;
        FundCite itemB = (FundCite)b;
        if ((null == itemA) && (null == itemB)) {
            ordering = 0;
        } else if ((null == itemA.getPrName()) && (null == itemB.getPrName())) {
            ordering = 0;
        } else if (null == itemA.getPrName()) {
            ordering = -1;
        } else if (null == itemB.getPrName()) {
            ordering = 1;
        } else {
            // Do primary sort by PR Name.
            ordering = itemA.getPrName().compareTo(itemB.getPrName());
            if (0 == ordering) {
                // Do secondary sort by CLIN.
                if ((null == itemA.getClin()) && (null == itemB.getClin())) {
                    ordering = 0;
                } else if (null == itemA.getClin()) {
                    ordering = -1;
                } else if (null == itemB.getClin()) {
                    ordering = 1;
                } else {
                    ordering = itemA.getClin().compareTo(itemB.getClin());
                }
            }
        }
        return ordering;
    }
}