How do I get the file name from a String containing the Absolute file path?

Alternative using Path (Java 7+):

Path p = Paths.get("C:\\Hello\\AnotherFolder\\The File Name.PDF");
String file = p.getFileName().toString();

Note that splitting the string on \\ is platform dependent as the file separator might vary. Path#getName takes care of that issue for you.

Using FilenameUtils in Apache Commons IO :

String name1 = FilenameUtils.getName("/ab/cd/xyz.txt");
String name2 = FilenameUtils.getName("c:\\ab\\cd\\xyz.txt");

Any file name/path manipulation should go through APIs in the java.nio.file package.

Specifically, the Path class

[...] may be used to locate a file in a file system. It will typically represent a system dependent file path.

A Path represents a path that is hierarchical and composed of a sequence of directory and file name elements separated by a special separator or delimiter. A root component, that identifies a file system hierarchy, may also be present. The name element that is farthest from the root of the directory hierarchy is the name of a file or directory. [...]

You can get an instance of type Path using the Paths factory method, get (or the FileSystems class as described here).

Once you have an appropriate Path instance representing your full path, you can use getFileName

Returns the name of the file or directory denoted by this path as a Path object. The file name is the farthest element from the root in the directory hierarchy.

For example,

String fullPathStr = "C:\Hello\AnotherFolder\The File Name.PDF";
Path fullPath = Paths.get(fullPathStr);
Path fileName = fullPath.getFileName();

Note: This all assumes you're running in a Windows environment (considering your file path). If not, you'll need to use a FileSystemProvider that supports Windows path naming.

Alternatively, with only string manipulation, and considering the String you're asking about is

C:\Hello\AnotherFolder\The File Name.PDF

we need to extract everything after the last separator, ie. \. That is what we are interested in.

You can do

String fullPath = "C:\\Hello\\AnotherFolder\\The File Name.PDF";
int index = fullPath.lastIndexOf("\\");
String fileName = fullPath.substring(index + 1);

This will retrieve the index of the last \ in your String and extract everything that comes after it into fileName.

If you have a String with a different separator, adjust the lastIndexOf to use that separator.

I've omitted it in the example above, but if you're unsure where the String comes from or what it might contain, you'll want to validate that the lastIndexOf returns a non-negative value because the Javadoc states it'll return

-1 if there is no such occurrence

Since 1.7

    Path p = Paths.get("c:\\temp\\1.txt");
    String fileName = p.getFileName().toString();
    String directory = p.getParent().toString();

The other answers didn't quite work for my specific scenario, where I am reading paths that have originated from an OS different to my current one. To elaborate I am saving email attachments saved from a Windows platform on a Linux server. The filename returned from the JavaMail API is something like 'C:\temp\hello.xls'

The solution I ended up with:

String filenameWithPath = "C:\\temp\\hello.xls";
String[] tokens = filenameWithPath.split("[\\\\|/]");
String filename = tokens[tokens.length - 1];

you can use path = C:\Hello\AnotherFolder\TheFileName.PDF

String strPath = path.substring(path.lastIndexOf("\\")+1, path.length());

getFileName() method of java.nio.file.Path used to return the name of the file or directory pointed by this path object.

Path getFileName()

For reference:

https://www.geeksforgeeks.org/path-getfilename-method-in-java-with-examples/

Considere the case that Java is Multiplatform:

int lastPath = fileName.lastIndexOf(File.separator);
if (lastPath!=-1){
    fileName = fileName.substring(lastPath+1);
}

A method without any dependency and takes care of .. , . and duplicate separators.

public static String getFileName(String filePath) {
    if( filePath==null || filePath.length()==0 )
        return "";
    filePath = filePath.replaceAll("[/\\\\]+", "/");
    int len = filePath.length(),
        upCount = 0;
    while( len>0 ) {
        //remove trailing separator
        if( filePath.charAt(len-1)=='/' ) {
            len--;
            if( len==0 )
                return "";
        }
        int lastInd = filePath.lastIndexOf('/', len-1);
        String fileName = filePath.substring(lastInd+1, len);
        if( fileName.equals(".") ) {
            len--;
        }
        else if( fileName.equals("..") ) {
            len -= 2;
            upCount++;
        }
        else {
            if( upCount==0 )
                return fileName;
            upCount--;
            len -= fileName.length();
        }
    }
    return "";
}

Test case:

@Test
public void testGetFileName() {
    assertEquals("", getFileName("/"));
    assertEquals("", getFileName("////"));
    assertEquals("", getFileName("//C//.//../"));
    assertEquals("", getFileName("C//.//../"));
    assertEquals("C", getFileName("C"));
    assertEquals("C", getFileName("/C"));
    assertEquals("C", getFileName("/C/"));
    assertEquals("C", getFileName("//C//"));
    assertEquals("C", getFileName("/A/B/C/"));
    assertEquals("C", getFileName("/A/B/C"));
    assertEquals("C", getFileName("/C/./B/../"));
    assertEquals("C", getFileName("//C//./B//..///"));
    assertEquals("user", getFileName("/user/java/.."));
    assertEquals("C:", getFileName("C:"));
    assertEquals("C:", getFileName("/C:"));
    assertEquals("java", getFileName("C:\\Program Files (x86)\\java\\bin\\.."));
    assertEquals("C.ext", getFileName("/A/B/C.ext"));
    assertEquals("C.ext", getFileName("C.ext"));
}

Maybe getFileName is a bit confusing, because it returns directory names also. It returns the name of file or last directory in a path.

extract file name using java regex *.

public String extractFileName(String fullPathFile){
        try {
            Pattern regex = Pattern.compile("([^\\\\/:*?\"<>|\r\n]+$)");
            Matcher regexMatcher = regex.matcher(fullPathFile);
            if (regexMatcher.find()){
                return regexMatcher.group(1);
            }
        } catch (PatternSyntaxException ex) {
            LOG.info("extractFileName::pattern problem <"+fullPathFile+">",ex);
        }
        return fullPathFile;
    }

You can use FileInfo object to get all information of your file.

    FileInfo f = new FileInfo(@"C:\Hello\AnotherFolder\The File Name.PDF");
    MessageBox.Show(f.Name);
    MessageBox.Show(f.FullName);
    MessageBox.Show(f.Extension );
    MessageBox.Show(f.DirectoryName);