Gradle : What is a FileCollection in Gradle Api

Introduction to FileCollection

FileCollection is an interface that extends Iterable<File>, AntBuilderAware and Buildable interfaces.

How to load files in a FileCollection

Suppose we have a file structure as shown in image below

We can load multiple files for operation using the following syntax

FileCollection collection = files('relative/path/file1','absolute/path/file2',new File('file3'))

As shown in the example above we can load files in three ways

1. From a relative path
2. From a absolute path
3. From a File object.

We can write a gradle task to read all files in a folder or directory as follows

task fileTree(){
    doLast{
        FileTree tree = fileTree('src')
        tree.each {
            println it.name
        }
    }
}

Now when we run the above gradle task with the command gradle -q fileTree, it will give the following output

sample1.txt
sample2txt
file1.properties
resources.tar.gz
resources.jar
resources.zip
A.java

Operations and methods available for FileCollection

1. getSingleFile() - It returns a single file. (it will throw IllegalStateException if files contains more than one file or no file)
2. getAsFileTree() - It returns the FileCollection as a FileTree.
3. plus(FileCollection collection) - It will add the specified file collection to the existing file collection.
4. minus(FileCollection collection) - It will remove from the collection files in specified collection.
5. filter(Closure filter) - It will filter the files from collection and make changes to the same collection.

Read More

• How to Get a File using Relative Path
• How to Get Multiple Files using FileCollection
• How to Get all files in a Directory using FileTree
• Difference between File, FileCollection and FileTree in Gradle