java - 重写匿名内部类方法不起作用

Question

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已关闭 3 年前。

你能用这种方式重写一个方法吗？

public class test {

    public static void main(String[] args) throws IOException {        
        File dir = new File("M:\\Java\\Test") {
            @Override
            public String[] list() { 
                String[] listA = super.list();                
                for (String s : listA) {
                    s = "test" + s;
                }                
                return listA;
            }
        };
        String[] listB = dir.list();
        for (String s : listB) {
            System.out.println(s);
        }
    }
}

我预计:

test1.txt
test10.txt
test2.txt
test3.txt
test4.txt
test5.txt
test6.txt
test7.txt
test8.txt
test9.txt

我收到:

1.txt
10.txt
2.txt
3.txt
4.txt
5.txt
6.txt
7.txt
8.txt
9.txt

我不能提出新问题，它涉及相同的代码，所以我会在这里问。嵌套方法重写是否导致编译器错误？

public class test {

    public static void main(String[] args) throws IOException {
        File dir = new File("M:\\Java\\Test") {
            @Override
            public String[] list() {
                String[] listA = super.list(new FilenameFilter() {
                    @Override
                    public boolean accept(File file, String string) {
                        return string.contains(".txt");
                    }
                });
                for (int i = 0; i < listA.length; i++) {
                    listA[i] = "test" + listA[i];
                }                                
                return listA;
            }
        };
        String[] listB = dir.list();
        for (String s : listB) {
            System.out.println(s);
        }
    }
}

我收到:

    Exception in thread "main" java.lang.StackOverflowError  
        at java.io.File.list(File.java:1155)  
        at findmyorder.test$1.list(test.java:22)  
        at java.io.File.list(File.java:1155)  
        at findmyorder.test$1.list(test.java:22)  
        at java.io.File.list(File.java:1155)  
        at findmyorder.test$1.list(test.java:22)  
        at java.io.File.list(File.java:1155)  
        at findmyorder.test$1.list(test.java:22)  
        at java.io.File.list(File.java:1155)  
        at findmyorder.test$1.list(test.java:22)  
        at java.io.File.list(File.java:1155)  
        at findmyorder.test$1.list(test.java:22)  
        at java.io.File.list(File.java:1155) 

它看起来像一些无限循环。添加FilenameFilter后出现问题到list()功能。这是嵌套@Override的结果吗？

Answer 1

您返回的是相同的列表。将您的 for 循环替换为:

        for(int i=0;i<listA.length;i++)
        {
            listA[i] = "test" + listA[i];
        }