How to combine paths in Java

Question

Is there a Java equivalent for System IO Path Combine   in C   NET  Or any code to accomplish this   This static method combines one or more strings into a path

User · Answer

The main answer is to use File objects  However Commons IO does have a class FilenameUtils that can do this kind of thing  such as the concat   method

User · Answer

Late to the party perhaps  but I wanted to share my take on this  I m using a Builder pattern and allow conveniently chained append more  calls  and allows mixing File and String  It can easily be extended to support working with Path objects as well  and furthermore handles the different path separators correctly on both Linux  Macintosh  etc  public class Files        public static class PathBuilder           private File file           private PathBuilder   File root                 file   root                     private PathBuilder   String root                 file   new File root                      public PathBuilder append   File more                 file   new File file  more getPath                   return this                     public PathBuilder append   String more                 file   new File file  more               return this                     public File buildFile                  return file                       public static PathBuilder buildPath   File root             return new PathBuilder root              public static PathBuilder buildPath   String root             return new PathBuilder root            Example of usage  File root   File listRoots   0   String hello    quot hello quot   String world    quot world quot   String filename    quot warez lha quot     File file   Files buildPath root  append hello  append world                 append filename  buildFile    String absolute   file getAbsolutePath     The resulting absolute will contain something like   hello world warez lha  or maybe even  A  hello world warez lha

User · Answer

This also works in Java 8    Path file   Paths get  Some path    file   Paths get file    Some other path

User · Answer

I know its a long time since Jon s original answer  but I had a similar requirement to the OP    By way of extending Jon s solution I came up with the following  which will take one or more path segments takes as many path segments that you can throw at it   Usage  Path combine   Users beardtwizzle     Path combine       Users    beardtwizzle    Path combine new String           Users    beardtwizzle    arrayUsage        Code here for others with a similar problem  public class Path       public static String combine String    paths                File file   new File paths 0             for  int i   1  i  lt  paths length   i                  file   new File file  paths i                       return file getPath

User · Answer

In Java 7  you should use resolve   Path newPath   path resolve childPath     While the NIO2 Path class may seem a bit redundant to File with an unnecessarily different API  it is in fact subtly more elegant and robust   Note that Paths get    as suggested by someone else  doesn t have an overload taking a Path  and doing Paths get path toString    childPath  is NOT the same thing as resolve    From the Paths get   docs      Note that while this method is very convenient  using it will imply an assumed reference to the default FileSystem and limit the utility of the calling code  Hence it should not be used in library code intended for flexible reuse  A more flexible alternative is to use an existing Path instance as an anchor  such as   Path dir       Path path   dir resolve  file       The sister function to resolve is the excellent relativize   Path childPath   path relativize newPath

User · Answer

Rather than keeping everything string-based  you should use a class which is designed to represent a file system path   If you re using Java 7 or Java 8  you should strongly consider using java nio file Path  Path resolve can be used to combine one path with another  or with a string  The Paths helper class is useful too  For example   Path path   Paths get  foo    bar    baz txt      If you need to cater for pre-Java-7 environments  you can use java io File  like this   File baseDirectory   new File  foo    File subDirectory   new File baseDirectory   bar    File fileInDirectory   new File subDirectory   baz txt      If you want it back as a string later  you can call getPath    Indeed  if you really wanted to mimic Path Combine  you could just write something like   public static String combine String path1  String path2        File file1   new File path1       File file2   new File file1  path2       return file2 getPath

User · Answer

Here s a solution which handles multiple path parts and edge conditions   public static String combinePaths String     paths      if   paths length    0          return            File combined   new File paths 0       int i   1    while   i  lt  paths length          combined   new File combined  paths i          i         return combined getPath

User · Answer

To enhance JodaStephen s answer  Apache Commons IO has FilenameUtils which does this   Example  on Linux    assert org apache commons io FilenameUtils concat   home bob    work  stuff log        home bob work stuff log    It s platform independent and will produce whatever separators your system needs

User · Answer

The main answer is to use File objects  However Commons IO does have a class FilenameUtils that can do this kind of thing  such as the concat   method

User · Answer

The main answer is to use File objects  However Commons IO does have a class FilenameUtils that can do this kind of thing  such as the concat   method

User · Answer

If you do not need more than strings  you can use com google common io Files  Files simplifyPath  some prefix with  extra   slashes     file  name     to get    some prefix with extra slashes file name

User · Answer

In Java 7  you should use resolve   Path newPath   path resolve childPath     While the NIO2 Path class may seem a bit redundant to File with an unnecessarily different API  it is in fact subtly more elegant and robust   Note that Paths get    as suggested by someone else  doesn t have an overload taking a Path  and doing Paths get path toString    childPath  is NOT the same thing as resolve    From the Paths get   docs      Note that while this method is very convenient  using it will imply an assumed reference to the default FileSystem and limit the utility of the calling code  Hence it should not be used in library code intended for flexible reuse  A more flexible alternative is to use an existing Path instance as an anchor  such as   Path dir       Path path   dir resolve  file       The sister function to resolve is the excellent relativize   Path childPath   path relativize newPath

User · Answer

This also works in Java 8    Path file   Paths get  Some path    file   Paths get file    Some other path

User · Answer

Rather than keeping everything string-based  you should use a class which is designed to represent a file system path   If you re using Java 7 or Java 8  you should strongly consider using java nio file Path  Path resolve can be used to combine one path with another  or with a string  The Paths helper class is useful too  For example   Path path   Paths get  foo    bar    baz txt      If you need to cater for pre-Java-7 environments  you can use java io File  like this   File baseDirectory   new File  foo    File subDirectory   new File baseDirectory   bar    File fileInDirectory   new File subDirectory   baz txt      If you want it back as a string later  you can call getPath    Indeed  if you really wanted to mimic Path Combine  you could just write something like   public static String combine String path1  String path2        File file1   new File path1       File file2   new File file1  path2       return file2 getPath

User · Answer

This solution offers an interface for joining path fragments from a String   array  It uses java io File File String parent  String child        public static joinPaths String   fragments            String emptyPath               return buildPath emptyPath  fragments              private static buildPath String path  String   fragments            if  path    null    path isEmpty                  path                          if  fragments    null    fragments length    0                return                        int pathCurrentSize   path split      length          int fragmentsLen   fragments length           if  pathCurrentSize  lt   fragmentsLen                String newPath   new File path  fragments pathCurrentSize - 1   toString                path   buildPath newPath  fragments                      return path          Then you can just do   String   fragments     dir    anotherDir      filename txt    String path   joinPaths fragments     Returns     dir anotherDir filename txt

User · Answer

platform independent approach  uses File separator  ie will works depends on operation system where code is running   java nio file Paths get       path    to    file txt      relative unix path    path to file txt    relative windows path    path to filee txt  java nio file Paths get       path    to    file txt      absolute unix path   path to filee txt    windows network drive path    path to file txt  java nio file Paths get  C     path    to    file txt      absolute windows path  C  path to file txt

User · Answer

Late to the party perhaps  but I wanted to share my take on this  I m using a Builder pattern and allow conveniently chained append more  calls  and allows mixing File and String  It can easily be extended to support working with Path objects as well  and furthermore handles the different path separators correctly on both Linux  Macintosh  etc  public class Files        public static class PathBuilder           private File file           private PathBuilder   File root                 file   root                     private PathBuilder   String root                 file   new File root                      public PathBuilder append   File more                 file   new File file  more getPath                   return this                     public PathBuilder append   String more                 file   new File file  more               return this                     public File buildFile                  return file                       public static PathBuilder buildPath   File root             return new PathBuilder root              public static PathBuilder buildPath   String root             return new PathBuilder root            Example of usage  File root   File listRoots   0   String hello    quot hello quot   String world    quot world quot   String filename    quot warez lha quot     File file   Files buildPath root  append hello  append world                 append filename  buildFile    String absolute   file getAbsolutePath     The resulting absolute will contain something like   hello world warez lha  or maybe even  A  hello world warez lha

User · Answer

If you do not need more than strings  you can use com google common io Files  Files simplifyPath  some prefix with  extra   slashes     file  name     to get    some prefix with extra slashes file name

User · Answer

Rather than keeping everything string-based  you should use a class which is designed to represent a file system path   If you re using Java 7 or Java 8  you should strongly consider using java nio file Path  Path resolve can be used to combine one path with another  or with a string  The Paths helper class is useful too  For example   Path path   Paths get  foo    bar    baz txt      If you need to cater for pre-Java-7 environments  you can use java io File  like this   File baseDirectory   new File  foo    File subDirectory   new File baseDirectory   bar    File fileInDirectory   new File subDirectory   baz txt      If you want it back as a string later  you can call getPath    Indeed  if you really wanted to mimic Path Combine  you could just write something like   public static String combine String path1  String path2        File file1   new File path1       File file2   new File file1  path2       return file2 getPath

User · Answer

To enhance JodaStephen s answer  Apache Commons IO has FilenameUtils which does this   Example  on Linux    assert org apache commons io FilenameUtils concat   home bob    work  stuff log        home bob work stuff log    It s platform independent and will produce whatever separators your system needs

User · Answer

Rather than keeping everything string-based  you should use a class which is designed to represent a file system path   If you re using Java 7 or Java 8  you should strongly consider using java nio file Path  Path resolve can be used to combine one path with another  or with a string  The Paths helper class is useful too  For example   Path path   Paths get  foo    bar    baz txt      If you need to cater for pre-Java-7 environments  you can use java io File  like this   File baseDirectory   new File  foo    File subDirectory   new File baseDirectory   bar    File fileInDirectory   new File subDirectory   baz txt      If you want it back as a string later  you can call getPath    Indeed  if you really wanted to mimic Path Combine  you could just write something like   public static String combine String path1  String path2        File file1   new File path1       File file2   new File file1  path2       return file2 getPath

User · Answer

platform independent approach  uses File separator  ie will works depends on operation system where code is running   java nio file Paths get       path    to    file txt      relative unix path    path to file txt    relative windows path    path to filee txt  java nio file Paths get       path    to    file txt      absolute unix path   path to filee txt    windows network drive path    path to file txt  java nio file Paths get  C     path    to    file txt      absolute windows path  C  path to file txt

User · Answer

This solution offers an interface for joining path fragments from a String   array  It uses java io File File String parent  String child        public static joinPaths String   fragments            String emptyPath               return buildPath emptyPath  fragments              private static buildPath String path  String   fragments            if  path    null    path isEmpty                  path                          if  fragments    null    fragments length    0                return                        int pathCurrentSize   path split      length          int fragmentsLen   fragments length           if  pathCurrentSize  lt   fragmentsLen                String newPath   new File path  fragments pathCurrentSize - 1   toString                path   buildPath newPath  fragments                      return path          Then you can just do   String   fragments     dir    anotherDir      filename txt    String path   joinPaths fragments     Returns     dir anotherDir filename txt

User · Answer

The main answer is to use File objects  However Commons IO does have a class FilenameUtils that can do this kind of thing  such as the concat   method

User · Answer

I know its a long time since Jon s original answer  but I had a similar requirement to the OP    By way of extending Jon s solution I came up with the following  which will take one or more path segments takes as many path segments that you can throw at it   Usage  Path combine   Users beardtwizzle     Path combine       Users    beardtwizzle    Path combine new String           Users    beardtwizzle    arrayUsage        Code here for others with a similar problem  public class Path       public static String combine String    paths                File file   new File paths 0             for  int i   1  i  lt  paths length   i                  file   new File file  paths i                       return file getPath

User · Answer

Here s a solution which handles multiple path parts and edge conditions   public static String combinePaths String     paths      if   paths length    0          return            File combined   new File paths 0       int i   1    while   i  lt  paths length          combined   new File combined  paths i          i         return combined getPath

[java] How to combine paths in Java?

Examples related to java

Examples related to path