Java Server-Side – Why Use Java Over Interpreted Language?

compilerinterpretersjavaruntimeweb

Web pages are usually tested by refreshing the page, clicking some UI component, then either writing to a debug log or adding some breakpoints in the IDE… in larger applications, unit tests are written to guarantee the output of the program, etc.

It seems like Java is an awful server-side language for a web page. You have to recompile every time you modify any line of code and pass the built EAR or WAR to the application server… something like Python or PHP (or any other interpreted language) would execute at run-time, removing the need for compilation before testing.

My question: what is the justification to using Java as a server-side language? Why is it better to use than an interpreted language?

Best Answer

There's the title of your question which is a valid one and then there is the content of the question which contains some poor assumptions and/or incorrect statements. I'll address the body first:

You have to recompile every time you modify any line of code and pass the built EAR or WAR to the application server...

Not true. First of all, technology exists for Java which allows you to modify code and have it change a running application without even restarting the application. I link to the product not to endorse it but rather as proof. I have used it and can verify that it works. Secondly, python must also be compiled. It's just when that compilation occurs. In java you do it ahead up front. In python it happens at runtime (the details may vary depending on the Python variant)

As far as why one would use a pre-compiled language, here are a few reasons off the top of my head

bytecode files are smaller than source files and servers (not being human) don't need source.
Compiling ahead of time allows you to catch syntactical errors. Why wait until you've loaded your file on the server to find out that you forgot a colon?

The rest of the reasons around why you would choose one over the other really aren't about when you compile. They tend to center around dynamic versus static code and the advantages and disadvantages between the two approaches. I would expect well written Java code to be faster than well written Python though this is a factor that can change over time in both actual speed and whether it matters.

Related Solutions

Scala vs Java – Why Use Scala Over Java

Disclaimer: I'm not a Scala guru.

Scala does two things extremely well which Java (currently) does not.

Solve functional problems

At the most basic level, Scala has fully fledged closures with collections support. This means you no longer have to write boiler plate code such as (shamelessly ripped off a DZone post)

public List<Item> bought(User user)
{
    List<Item> result = new ArrayList();
    for (Item item : currentItems)
    {
        if (user.bought(item))
        {
            result.add(item);
        }
    }
    return result;
}

But instead write something like:

def bought(user: User) = items.filter(user bought _)

There's more functional love, but I'm not qualified to talk about it since I currently still suck at functional programming :)

Solve concurrency in a safer way

Scala has an actors model (+ some other goodness) which is inheritly safer than Java's mutable data + locks on Thread model (no matter how good the libs are getting, Java is still hindered by the language).

I can't honestly think of too much else that makes Scala stand head and shoulders above Java. Lots of small gains and improvements yes, but also far more rope to hang yourself with. YMMV

HTH a little

Objective-C – Is It an Interpreted or Compiled Language?

It is neither. Objective-C is a programming language. A programming language is an abstract concept. A programming language is a set of mathematical rules and definitions. Programming languages aren't compiled or interpreted, they just are.

Compilation and interpretation aren't properties of a programming language, they are properties of, well, a compiler or an interpreter (duh). Every language can be implemented by a compiler and an interpreter, and most languages have both compiled and interpreted implementations. In fact, the majority of modern language implementations utilize both an interpreter and a compiler in the same execution engine for maximum performance.

For Objective-C specifically, I know of three implementations: gobjc, clang and oscompiler, but a quick Google search turned up two more. Of those five implementations, three are compilers and two are interpreters.

Best Answer

Related Solutions

Scala vs Java – Why Use Scala Over Java

Objective-C – Is It an Interpreted or Compiled Language?

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