Question

我有这段代码

List<JComponent> myList = new ArrayList<>();
fillmyList(myList); //Some method filling the list
try{
    menuList.stream()
    .filter(m->m.getClass().getMethod("setFont", new Class[]{Font.class}) != null) //unreported exception NoSuchMethodException; must be caught or declared to be thrown
    .forEach(m -> m.setFont(someFont));
}
catch (NullPointerException |  NoSuchMethodException e) {} //exception NoSuchMethodException is never thrown in body of corresponding try statement

但是，我有这个错误消息：

Exception in thread "AWT-EventQueue-0" java.lang.RuntimeException: Uncompilable source code - exception java.lang.NoSuchMethodException is never thrown in body of corresponding try statement

如何解决这个问题？

Answer 1

这不是例外，而是编译错误你必须捕获可能抛出异常的lambda体，而不是整个流。

以下是在false中为已抛出异常的流的元素返回filter()的示例：

myList.stream()
      .filter(m -> {
          try {
              return m.getClass()
                      .getMethod("setFont", new Class[] { Font.class }) != null;
          } catch (NoSuchMethodException | SecurityException e) {
              // log the exception
              return false;
          }
      })

您当然可以使用不同的策略来抛出RuntimeException并停止处理。

Java 8，流过滤器，反射，NoSuchMethodException

1 个答案: