Search a file in java

Files ;. Path ;. Paths ;. FileSystems ;. FileVisitResult ;. PathMatcher ;. SimpleFileVisitor ;. BasicFileAttributes ;. Path interface in Java8. You have total In Java How to get list of files and search a file providing folder path?

FilenameFilter Interface Example. Join the Discussion If you liked this article, then please share it on social media. Other Popular Articles In Java How to get list of files and search files from given folder? Most beginners to Java have no clue where to even begin. Well Dream. Code and Martyr2 to the rescue! As super heroes, we fight the baddies which cause confusion and mayhem and bring you the straight scoop. So worry not programming citizen, we are on the job in this episode of the Programming Underground!

Up Up and Awayyyyyy! It is a plane! No it is a text file! Say what? In this example we will be creating a small program which opens a standard text file and searches for a word or phrase we provided at runtime as a parameter. This class is designed to open a file and create a stream of data buffered for us to then read from and use. To get the process started we will give it a plain FileReader object initialized with a file that we want to search.

For simplicity sake I hardcoded this value in the program but you could easily use another parameter for the filename to search. I will leave that part up to you. So once we have this file open we begin the process of reading through the file line by line. We will do this using a while loop that reads the line, checks if anything was read, then begins our most basic search on that line.

The process looks like this…. Our supplied parameter to this program is going to come into the program through the args[] array. If you have ever wondered what that args[] array was for, now you know.

No use conducting the search if there is no word to search for. In fact, you have probably used it extensively. If you haven't used it, pattern matching uses special characters to create a pattern and then file names can be compared against that pattern. For example, the following command lists all the files in the current directory that end in. The java. Each file system implementation provides a PathMatcher.

The following code snippet fetches the path matcher for the default file system:. The string argument passed to getPathMatcher specifies the syntax flavor and the pattern to be matched. This example specifies glob syntax. If you are unfamiliar with glob syntax, see What is a Glob.

Glob syntax is easy to use and flexible but, if you prefer, you can also use regular expressions, or regex , syntax.