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In order to code fancy applications, developers rely heavily on other people's code, or *libraries*. These libraries are made available as JAR files to anyone who wants to use them. In this video, you'll be introduced to the process of using a third-party library in your own code.
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Welcome back.
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If you're here now, Im guessing you have IntellaJ installed and ready to go.
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Nicely done.
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If not, be sure to hit up the forum with your questions and
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the community can help you get going.
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The next tool I wanna discuss will be used to manage the third party libraries we
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use in our project.
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Namely, the spring libraries.
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The spring framework that we'll be using is not included in the Java core library.
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That being the case, we'll need to save those libraries into our projects so
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that we can use the familiar import statements
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to reference spring code from the code that we're writing.
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Technically this amounts to adding JAR files to the class path.
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The who and the what now?
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Let's dissect that a little bit, starting with the class path.
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If you've been through some of our previous courses,
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you may have experience using the class path.
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In Java, the class path consists of one or
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more directories that contain all the Java files associated with our project.
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This is an option we can specify, while compiling or running a Java program.
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[NOISE] So if there are outside code libraries, the directory where they're
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saved should be a part of the class path [NOISE] that's given to the Java compiler
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while compiling, and to the Java virtual machine while running.
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Hey, speaking of code libraries,
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let's circle back to another term I mentioned just a few moments ago.
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I said that we'll need to add JAR files to the class path.
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What are these JAR files?
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If you haven't guessed yet,
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these are indeed the code libraries I'm referring to.
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Let's take a closer look.
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JAR stands for Java Archive.
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A JAR file is essentially a bundle of compiled Java code.
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The files are bundled together just like a zip file.
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Except that the Z-I-P extension, a JAR file has the J-A-R extension.
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What this amounts to is that you can write a bunch of Java code then distribute that
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code as an application or library by generating a JAR file.
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Generating one of these can be done from most Java IDEs, including IntelligiJ, or
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from the command line with the JDK's JAR command.
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After generating a JAR file, all developers need to do is
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download the JAR file that you've created and add its location to their classpath.
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Then they can start creating and
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interacting with objects from the classes that you defined.
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Since the JAR file only includes your pipe code,
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they can do this without you ever having to reveal your source code.
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Now, that's pretty cool stuff.
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As a heads up on terminology, I'll be using the terms JAR and
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library synonymously.
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Let's take a short break here and in the next video
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we'll talk about how we're going to fetch all those fancy libraries.
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It turns out that the tool we're gonna use
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is one of the most widely used tools in the industry.
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