没有找到适合 File(file) 的构造函数

Question

我一直到那里错误：

    error: no suitable constructor found for File(File)
            File file = new File(testFile);
                        ^
constructor File.File(String,int) is not applicable
  (actual and formal argument lists differ in length)
constructor File.File(String,File) is not applicable
  (actual and formal argument lists differ in length)
constructor File.File(String) is not applicable
  (argument mismatch; File cannot be converted to String)
constructor File.File(String,String) is not applicable
  (actual and formal argument lists differ in length)
constructor File.File(File,String) is not applicable
  (actual and formal argument lists differ in length)
constructor File.File(URI) is not applicable
  (argument mismatch; File cannot be converted to URI)

我不明白错误在告诉我什么，有人可以解释一下吗？这是我的代码：

    public ShortenWord( File testFile ) {
    try {
        File file = new File(testFile);
        Scanner in = new Scanner(file);

        List originalWords = new List();
        List abbWords = new List();

        while (in.hasNextLine())
        {
            String line = in.nextLine();
            String[] parts = line.split(",");
            String originalWord = parts[0];
            String abbWord = parts[1];
        }
    }
catch (FileNotFoundException e)
    {
        System.out.println(e);
    }
}

如能提供有关如何修复此错误的任何帮助，我们将不胜感激。因为我不知道 :)

Answer 1

File class 没有带有 File 参数的构造函数（也称为复制构造函数）。

如果您已经将 File 传递给 ShortenWord 构造函数，只需使用它而不是尝试创建新的 File :

public ShortenWord( File testFile ) {
  try {
    Scanner in = new Scanner(testFile);

    List originalWords = new List();
    List abbWords = new List();

    while (in.hasNextLine())
    {
        String line = in.nextLine();
        String[] parts = line.split(",");
        String originalWord = parts[0];
        String abbWord = parts[1];
    }
  }
  catch (FileNotFoundException e)
  {
      System.out.println(e);
  }
}

Answer 2

文件构造函数期望文件路径名作为单个参数的字符串。您不应该在 File 构造函数中传递另一个文件对象。

File file = new File("somefilename.txt");

Answer 3

查看 Javadoc：http://docs.oracle.com/javase/7/docs/api/java/io/File.html

有 4 个构造函数，其中 none 个以文件作为参数：

File(File parent, String child)
Creates a new File instance from a parent abstract pathname and a child pathname string.
File(String pathname)
Creates a new File instance by converting the given pathname string into an abstract pathname.
File(String parent, String child)
Creates a new File instance from a parent pathname string and a child pathname string.
File(URI uri)
Creates a new File instance by converting the given file: URI into an abstract pathname.

尝试使用字符串作为参数。

没有找到适合 File(file) 的构造函数

No Suitable constructor found for File(file)

java

java.util.scanner