How to display file content in AL11 directory

Let say i have below files in AL11 directory:

/folder1/folder2/file1.pdf

/folder1/folder2/file2.xls

/folder1/folder2/file3.doc

How to display the content of file1, file2 or file3 using ABAP code?

User key-in the complete path /folder1/folder2/file1.pdf, and my program should display the content. How to code this? Code sample are welcome. Thanks.