Java泛型：通配符捕获编译错误

Question

我得到以下编译错误：

The method sort(List<T>, Comparator<? super T>) in the type Collections is not applicable for the arguments (T[], Comparator<capture#1-of ? extends T>) Main.java   /Sorting/src/com/kash/test  line 11
The method sort(List<T>, Comparator<? super T>) in the type Collections is not applicable for the arguments (T[], Comparator<capture#2-of ? super T>)   Main.java   /Sorting/src/com/kash/test  line 15
The method sort(List<T>, Comparator<? super T>) in the type Collections is not applicable for the arguments (T[], Comparator<T>)    Main.java   /Sorting/src/com/kash/test  line 19

当我编译（在Eclipse Juno中使用JDK 1.7.0）以下代码时：

package com.kash.test;

import java.util.Collections;
import java.util.Comparator;

// 3 attempts to write a wrapper over: Collections' method
//      public static <T> void sort(List<T> list, Comparator<? super T> c)
public class Main {

    public static <T> void sort1(T[] array, Comparator<? extends T> c) {
        Collections.sort(array, c); // line 11
    }

    public static <T> void sort2(T[] array, Comparator<? super T> c) {
        Collections.sort(array, c); // line 15
    }

    public static <T> void sort3(T[] array, Comparator<T> c) {
        Collections.sort(array, c); // line 19
    }

    public static void main(String[] args) {

    }
}

null

package com.kash.src;

import java.util.Comparator;
import java.util.List;

/**
 * Interface that provides all sorting functions for all possible representations of a list of Objects (non-primitive
 * types). <br>
 * - {@link List}<{@link Comparable}><br>
 * - Array of < ? extends {@link Comparable}><br>
 * - {@link List}< ? > with external {@link Comparator}<br>
 * - Array of < ? > with external {@link Comparator}<br>
 * 
 * @author Kashyap Bhatt
 * 
 */

public interface Sorter {
    <T extends Comparable<T>> void sort(List<T> list);

    <T extends Comparable<T>> void sort(T[] array);

    <T extends Object> void sort(List<T> list, Comparator<? super T> c);

    <T extends Object> void sort(T[] array, Comparator<? super T> c);
}

这样我就可以测试我所有的排序实现并测试它们。我想将结果与Java的排序实现进行比较，所以我也在编写这个接口的实现，它在内部只调用Java的排序方法。这就是我面对问题的地方。

Answer 1

collections.sort()不对数组进行排序，但lists。