Read File/Directory properties with java

Question

How can I read the file information (for example size, line count, last modification, etc) from a file in the file-system or the directory content with JAVA? I need it for a linux operating system.

Thanks

Ps. This is my first question, althought I have user this forum for a while so please be kind :P

Answer 1

Try looking in to the File api. There are a bunch of methods like 'lastModified', 'length', and most of what you should need.

Answer 2

Use File class (except for line count - see this Q/A for that)

java.io.File.length()

lastModified()

Also, if you can get your Java program to make a system call, you can use Unix's wc -l command to count the lines for you - might be faster than Java but costs you a spawned-off process

Answer 3

For what it is worth, "line count" is not a file attribute in UNIX or Linux.

If you want a line count (assuming that it is a valid concept) you need to figure it out by reading the file. Simply counting newline characters gives a roughly correct answer for "text" files, but it may give a bogus answer in other cases. A complete answer involves:

• determining the file's type,
• deciding whether "line count" makes sense for the file type,
• deciding whether to count the lines or retrieve a line count from the file's internal metadata, and
• (if necessary) counting the lines in a way that is appropriate to the file type.