Question

I have a java program that reads each line in a file text and processes the text of a file, then print the result. I need to do the same thing for each file exist in a specific folder (directory). So, I need the program to go through each file in the folder and extract the content of the text ..etc. my question is how can I loop through each file in a folder using Java.

Answer 1

Once you created a File object that refers to the directory, you can call listFiles to get an array of all the files in the directory.

// assuming myDir is the File object that represents the directory
File[] dirContent = myDir.listFiles();
for (File f : dirContent)
{
    if (!f.isDirectory())
    {
        // process file.
    }
}

Alternatively, you can get only the list of files that are not directories by calling File#listFiles(FileFilter) with an appropriate file filter. E.g.:

// assuming myDir is the File object that represents the directory
File[] dirContent = myDir.listFiles(new FileFilter() {
    @Override boolean accept(File pathname)
    {
        return !pathname.isDirectory();
    }
});
for (File f : dirContent)
{
    // process file.
}