java - "No suitable method found for sort(List<VarStatusMsg<? extends Number>>)"JDK错误

Question

在 Java 源代码上运行 Ant 构建时遇到以下错误:

[javac] /home/path/to/my/java/function/VarStatusLog.java:28: error: no suitable method found for sort(List<VarStatusMsg<? extends Number>>)
[javac]         Collections.sort(logMsg);
[javac]                    ^
[javac]     method Collections.<T#1>sort(List<T#1>) is not applicable
[javac]       (inference variable T#1 has incompatible bounds
[javac]         equality constraints: VarStatusMsg<? extends Number>
[javac]         upper bounds: VarStatusMsg<CAP#1>,Comparable<? super T#1>)
[javac]     method Collections.<T#2>sort(List<T#2>,Comparator<? super T#2>) is not applicable
[javac]       (cannot infer type-variable(s) T#2
[javac]         (actual and formal argument lists differ in length))
[javac]   where T#1,T#2 are type-variables:
[javac]     T#1 extends Comparable<? super T#1> declared in method <T#1>sort(List<T#1>)
[javac]     T#2 extends Object declared in method <T#2>sort(List<T#2>,Comparator<? super T#2>)
[javac]   where CAP#1 is a fresh type-variable:
[javac]     CAP#1 extends Number from capture of ? extends Number

我在 Ant 构建中使用 JDK 1.8。请注意，Windows 上的 Eclipse 不会引发错误，但当我在 Linux 上从命令行运行时，会收到错误。有人可以帮我解决这个问题吗？提前致谢!

Answer 1

我会说VarStatusMsg未实现接口(interface)Comparable<VarStatusMsg> 。 sort的签名您使用的方法是 public static <T extends Comparable<? super T>> void sort(List<T> list) 。要么让你的 VarStatusMsg实现接口(interface)Comparable<VarStatusMsg> ，或给出 Comparator<VarStatusMsg>作为 sort 的第二个参数.

顺便说一句。您只需调用 logMsg.sort(null)而不是Collections.sort(logMsg)或logMsg.sort(myNiceComparator)而不是Collections.sort(logMsg, myNiceComparator) 。 Collections方法仅委托(delegate)给 List如今。