How to copy a file in Java

The easiest way to copy a file in Java is to download the Apache Commons IO library; just download their library, then use the methods of their FileUtils class to copy a file.

However, if you're just as interested in the technical details of how to copy a file in Java, or just want a method to copy a file in Java, the method below, taken from my Java file utilities class, shows how this actually works:

Java “file write” (or “file save”) methods

Java write/save FAQ: Can you share an example of how to write to a file in Java?

Sure. Here are two "Java file save" or "Java file write" examples, taken from my Java file utilities article (Java file utilities to write, save, open, read, and copy files). I'm not going to explain these too much, but if you need a simple method to write to a file in your Java programs, I hope these methods will help you.

How to open and read a text file in Java (FileReader, BufferedReader)

Java File I/O FAQ: How do I open a file and read text from it using Java? (Also written as, “How do I use the Java BufferedReader and FileReader classes to read from a text file?”)

Solution: Here’s a method taken from a Java class I wrote that shows how to open and read a file using the Java FileReader class. This uses the most recent Java syntax and classes.

A Java socket client class (example source code)

Summary: This article shares the source code for a simple Java Socket client class. This article demonstrates both (a) how to write to a Java socket, and (b) how to read from a Java socket.

How to use the Commons IO project to create, delete, and move files and directories

I wrote the following Java class today that is a "helper" class for a project I'm working on to create a web interface for Nagios. The Nagios part isn't too relevant, because mostly what I'm trying to show here is how to use the Apache Commons IO project to make it easier to interact with files and directories from Java code.

In short, the following Java class shows how to use the Commons IO project to accomplish the following tasks. Without any further delay, here is the complete source code for my class:

What is a Java IOException?

Java Exception FAQ: What is a Java IOException?

An IOException can occur in a variety of ways when you try to access the local filesystem. In the following Java code segment an IOException can be thrown by the br.readLine() method, so a try/catch wrapper is used around that portion of code to trap (and arguably deal with) the potential problem: