从 url 中下载文件时的错误

Question

我想从url中读取一个文件，然后定义它为一个File Type

public File fileFromUrl(String str) throws IOException
      {
          File file = new File ("image.png");
          URL url = new URL (str);
            InputStream input = url.openConnection().getInputStream();
            try {

                OutputStream output = new FileOutputStream (file);
                try {
                    byte[] buffer = new byte[1024];
                    int bytesRead = 0;
                    while ((bytesRead = input.read(buffer, 0, buffer.length)) >= 0) {
                        output.write(buffer, 0, bytesRead);
                    }
                } finally {
                    output.close();
                }
            } finally {
                input.close();
            }
          return file;
      }

但是代码在OutputStream output = new FileOutputStream (file); 处出错了。
请问如何定义 URl 中的文件？

Answer 1

   /**
     * Constructs a new file using the specified path.
     *
     * @param path
     *            the path to be used for the file.
     */
    public File(String path) {
        this.path = fixSlashes(path);
    }

这是File的构造方法，你那是找不到文件的 path应该是绝对路径