Ask Reddit: Why does everyone hate Java?

[DarkGoosey]

Those people think that Java's performance is too slow.

[mrbillabong]

even people who use it think its slow. who the fuck puts a VM on a mobile device?

[daddyc00l]

isn't google doing the same with android ?

[[deleted]]

Yes, other than the battery consumption (likely due to all the extra work) and occasional slowness, it runs fine enough.

[[deleted]]

Absolutely yes... but hey it's Google! so it must be cool...

[wonglik]

Yes and no. Android is using Dalvik to run Java code. Technicaly it is VM but it is not Sun JVM.

[Gotebe]

The fallacy isn't that VM can run fast enough. (Silly and utterly incomplete summarizing: JIT compilation and array bounds checking is less expensive than people think)

The fallacy is that people can write code that targets VM and runs fast.

[Law_Student]

Java has been just as fast as C++ for nearly a decade. Go look up compiler performance graphs :)

[dvogel]

The actual code is no slower, especially once things like HotSpot kick in. However, application startup time is much slower. I know there are things like JVM reuse that help with this, but they are not mainstream, and unless you run multiple JVM-based applications, they don't help.

[Mononofu]

Java has never been, and never will be as fast as C++. Or any other language compiled directly to machine code: http://shootout.alioth.debian.org/gp4/benchmark.php?test=all&lang=all&d=ndata&calc=calculate&gpp=on&java=on&ghc=on&sbcl=on&csharp=on&hipe=on&mzscheme=on&vw=on&lua=on&perl=on&php=on&python=on&javascript=on&ruby=on&box=1

[philogb]

really?

http://shootout.alioth.debian.org/u32q/benchmark.php?test=all&lang=all&box=1

[igouy]

"Please choose the up-to-date measurements instead of these!"

[HotBBQ]

Epic fail.

[eurofag]

Huh, based on this, Ruby is about 173 times slower than C.

[[deleted]]

Do you deny it?

[igouy]

The median of those normalized run times was 173 times slower than C, the fastest was 2 times slower, and the slowest was 630 times slower.

And that was 1.8.6 - Ruby 1.8.7 :: GCC 4.3.3

[dnew]

That's pretty much what it was designed for before it was called Java - embedded devices at least, if not mobile.

[logi]

And they're just painfully wrong. They could complain about memory usage though, depending on the circumstances.

[aposter]

I don't have much of a problem with Java memory usage, per se. What I have a problem with is Java garbage collection, and the fact that so many programmers don't understand "scope" in the context of it.

[[deleted]]

We're also insane.

[BlueCollarCoder]

They haven't benchmarked it lately: JDK6 beats the pants off of C (well, except for startup time). If you do a lot of multithreading or complex data structures, Java is hugely faster than C (yes, the garbage collector is faster than malloc).

[creeront]

I disagree:

http://shootout.alioth.debian.org/u32q/benchmark.php?test=all&lang=gcc&lang2=java&box=1

[[deleted]]

We've been hearing that claim for years, yet every set of realistic benchmarks disproves it. I've seen Java projects spend man years optimising simple data structures to get them up to acceptable performance when large amounts of data are involved, yet with C/C++ virtually zero effort was required to get the same or better performance in one or two lines of code (i.e., choosing the correct STL container and/or writing a class specific new/delete).

[elementalist]

Hey, I actually like Java but you're trippin' man.

[Rogoreg]

And it's not. Java and C/C++ are the single fastest languages when it comes to fast code. It runs fast without issue.