通过在Java SE 7中使用nio，

import java.nio.file.*;

Path path = Paths.get(filePathString);

if (Files.exists(path)) {
  // file exist
}

if (Files.notExists(path)) {
  // file is not exist
}

如果exists和notExists都返回false，则不能验证文件是否存在。(可能没有访问该路径的权限)

您可以检查path是目录还是普通文件。

if (Files.isDirectory(path)) {
  // path is directory
}

if (Files.isRegularFile(path)) {
  // path is regular file
}

请查看Java SE 7教程。

有多种方法可以实现这一点。

In case of just for existence. It could be file or a directory. new File("/path/to/file").exists(); Check for file File f = new File("/path/to/file"); if(f.exists() && f.isFile()) {} Check for Directory. File f = new File("/path/to/file"); if(f.exists() && f.isDirectory()) {} Java 7 way. Path path = Paths.get("/path/to/file"); Files.exists(path) // Existence Files.isDirectory(path) // is Directory Files.isRegularFile(path) // Regular file Files.isSymbolicLink(path) // Symbolic Link

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 .

通过在Java SE 7中使用nio，

import java.nio.file.*;

Path path = Paths.get(filePathString);

if (Files.exists(path)) {
  // file exist
}

if (Files.notExists(path)) {
  // file is not exist
}

如果exists和notExists都返回false，则不能验证文件是否存在。(可能没有访问该路径的权限)

您可以检查path是目录还是普通文件。

if (Files.isDirectory(path)) {
  // path is directory
}

if (Files.isRegularFile(path)) {
  // path is regular file
}

请查看Java SE 7教程。

熟悉Commons FileUtils https://commons.apache.org/proper/commons-io/javadocs/api-2.5/org/apache/commons/io/FileUtils.html也是非常值得的 它有额外的管理文件的方法，通常比JDK更好。

不要在String中使用File构造函数。 这可能行不通! 而不是使用URI:

File f = new File(new URI("file:///"+filePathString.replace('\\', '/')));
if(f.exists() && !f.isDirectory()) { 
    // to do
}