You must use the file class , create a file instance with the path of the file you want to check if existent . After that you must make sure that it is a file and not a directory . Afterwards you can call exist method on that file object referancing your file . Be aware that , file class in java is not representing a file . It actually represents a directory path or a file path , and the abstract path it represents does not have to exist physically on your computer . It is just a representation , that`s why , you can enter a path of a file as an argument while creating file object , and then check if that folder in that path does really exist , with the exists() method .

使用java.io.File:

File f = new File(filePathString);
if(f.exists() && !f.isDirectory()) { 
    // do something
}

你可以这样做

import java.nio.file.Paths;

String file = "myfile.sss";
if(Paths.get(file).toFile().isFile()){
    //...do somethinh
}

不喜欢。只是捕捉FileNotFoundException。文件系统必须测试文件是否存在。把所有的事情都做两次是没有意义的，原因如下:

双倍代码 计时窗口问题，即文件可能在测试时存在，但在打开时不存在，反之亦然 事实上，这个问题的存在表明，你可能做了错误的测试，得到了错误的答案。

不要试图猜测这个系统。它知道。不要试图预测未来。一般来说，测试任何资源是否可用的最佳方法就是尝试使用它。

如果使用spring框架，文件路径以classpath开头:

public static boolean fileExists(String sFileName) {
    if (sFileName.startsWith("classpath:")) {
        String path = sFileName.substring("classpath:".length());
        ClassLoader cl = ClassUtils.getDefaultClassLoader();
        URL url = cl != null ? cl.getResource(path) : ClassLoader.getSystemResource(path);
        return (url != null);
    } else {
        Path path = Paths.get(sFileName);
        return Files.exists(path);
    }
}

对我来说，Sean A.O. Harney的回答和Cort3z的评论似乎是最好的解决方案。

使用以下代码段:

File f = new File(filePathString);
if(f.exists() && f.isFile()) {
    //do something ...
}

希望这能帮助到一些人。