How do I check if a file exists in Java

Question

How can I check whether a file exists  before opening it for reading in Java  the equivalent of Perl s -e  filename       The only similar question on SO deals with writing the file and was thus answered using FileWriter which is obviously not applicable here   If possible I d prefer a real API call returning true false as opposed to some  Call API to open a file and catch when it throws an exception which you check for  no file  in the text   but I can live with the latter

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I would recommend using isFile   instead of exists    Most of the time you are looking to check if the path points to a file not only that it exists  Remember that exists   will return true if your path points to a directory   new File  path to file txt   isFile      new File  C     exists   will return true but will not allow you to open and read from it as a file

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f isFile    amp  amp  f canRead

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There are multiple ways to achieve this     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    amp  amp  f isFile        Check for Directory   File f   new File   path to file       if f exists    amp  amp  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

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first hit for  java file exists  on google   import java io     public class FileTest       public static void main String args              File f   new File args 0            System out println f    f exists      is found       is missing

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Don t  Just catch the FileNotFoundException  The file system has to test whether the file exists anyway  There is no point in doing all that twice  and several reasons not to  such as    double the code the timing window problem whereby the file might exist when you test but not when you open  or vice versa  and the fact that  as the existence of this question shows  you might make the wrong test and get the wrong answer    Don t try to second-guess the system  It knows  And don t try to predict the future  In general the best way to test whether any resource is available is just to try to use it

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For me a combination of the accepted answer by Sean A O  Harney and the resulting comment by Cort3z seems to be the best solution   Used the following snippet   File f   new File filePathString   if f exists    amp  amp  f isFile            do something         Hope this could help someone

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Simple example with good coding practices and covering all cases     private static void fetchIndexSafely String url  throws FileAlreadyExistsException           File f   new File Constants RFC INDEX LOCAL NAME           if  f exists                  throw new FileAlreadyExistsException f getAbsolutePath               else               try                   URL u   new URL url                   FileUtils copyURLToFile u  f                 catch  MalformedURLException ex                    Logger getLogger RfcFetcher class getName    log Level SEVERE  null  ex                 catch  IOException ex                    Logger getLogger RfcFetcher class getName    log Level SEVERE  null  ex                                   Reference and more examples at    https   zgrepcode com examples java java nio file filealreadyexistsexception-implementations

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You can make it this way  import java nio file Paths   String file    myfile sss   if Paths get file  toFile   isFile              do somethinh

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By using nio in Java SE 7   import java nio file     Path path   Paths get filePathString    if  Files exists path          file exist    if  Files notExists path          file is not exist     If both exists and notExists return false  the existence of the file cannot be verified   maybe no access right to this path   You can check if path is a directory or regular file   if  Files isDirectory path          path is directory    if  Files isRegularFile path          path is regular file     Please check this Java SE 7 tutorial

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There is specific purpose to design these methods  We can t say use anyone to check file exist or not    isFile    Tests whether the file denoted by this abstract pathname is a normal file  exists    Tests whether the file or directory denoted by this abstract pathname exists  docs oracle com

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File f   new File filePathString      This will not create a physical file  Will just create an object of the class File  To physically create a file you have to explicitly create it   f createNewFile      So f exists   can be used to check whether such a file exists or not

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I know I m a bit late in this thread  However  here is my answer  valid since Java 7 and up   The following snippet  if Files isRegularFile Paths get pathToFile             do something     is perfectly satifactory  because method isRegularFile returns false if file does not exist  Therefore  no need to check if Files exists        Note that other parameters are options indicating how links should be handled  By default  symbolic links are followed   From Java Oracle documentation

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Using Java 8   if Files exists Paths get filePathString              do something

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It s also well worth getting familiar with Commons FileUtils https   commons apache org proper commons-io javadocs api-2 5 org apache commons io FileUtils html This has additional methods for managing files and often better than JDK

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Using java io File   File f   new File filePathString   if f exists    amp  amp   f isDirectory              do something

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You can use the following  File exists

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Don t use File constructor with String  This may not work   Instead of this use URI   File f   new File new URI  file      filePathString replace               if f exists    amp  amp   f isDirectory              to do

[java] How do I check if a file exists in Java?

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