Archive for the ‘Java’ Category

Java C# Similarities

November 14, 2010
Part 1

In this post, I’m just going to go over setting up command line compilers for C# and Java.

I was recently helping someone with a Java based project, so had to brush up on my skills in that area.
I haven’t had a need to use Java for a while.
Java is quite similar to C# in many ways.
When it comes to working out the similarities, I think it’s actually easier to work out the differences, because there are less of them.
It often feels like C# is just a more mature Java, with more features and bigger libraries.
In saying that, Java also has benefits over C#.
We’ll explore some of these in this series.

Without further ado, let’s get started.
The first thing I looked at doing, which I’d been meaning to for a while, was to set up command line compilation for both C# and Java on Windows 7.
The idea is that you can just run a command prompt and the directory that cmd puts you in (C:\Users\Me>), you have access to a source file or files you can build, debug and run.
This saves littering the world with Visual Studios File->New->Project->Console Application’s.

C# compiler setup

You’ll want to make sure you have the .net framework installed.

You’ll need to make sure you have your path variable included for csc.exe (the C# compiler).
There are several ways you can get to your path setup.
I normally just hit the keys [Windows] + [Pause-Break] combination, which brings up System Properties.

 

Go to the Advanced tab, and click the Environment Variables button.
I normally just enter the location of the compiler into the variables for the current user.
Select path, click edit.

 

I’m using .net 4. My path was C:\Windows\Microsoft.NET\Framework\v4.0.30319
If you already have other paths in the text field, past the same path in at the end of the line, but with a semi colon immediately before it.
Like so…

;C:\Windows\Microsoft.NET\Framework\v4.0.30319

If there is no existing path, add one by clicking the New button instead of the Edit button.
OK and apply all of that.
Now at your command prompt if you run path

C:\Users\Me>path

you will see all your path variables.
Now you can just add a file into C:\Users\Me\
This can be the file that you put your C# code into (I just called this “scratch”).

Once you think you’ve got your C# code compilable.
From the command prompt, type.

C:\Users\Me>csc scratch

That’s it, providing you have no errors your assembly is built.
If you’d like to know what’s in your assembly have a look here

Now if you want to debug with the likes of cordbg.exe, you’ll need the .NET SDK
You can find it here
At 600MB… I passed on this.
If you do decide to install the SDK, you’ll need to add the path, then you should be good to start using cordbg.exe.
Details on how to use cordbg.exe are here

I found the following links helpful.
http://www.johnsmiley.com/cis18/Smiley037.pdf
http://msdn.microsoft.com/en-us/library/ms379563%28VS.80%29.aspx
http://blogs.msdn.com/b/windowssdk/archive/2010/05/25/released-windows-sdk-for-windows-7-and-net-framework-4.aspx

Java compiler setup

If you haven’t already got it installed, you’ll need the Java Development Kit (JDK).
If you have the Java Runtime Environment (JRE) installed, this doesn’t mean you have the JDK.
If you have the JDK installed, you’ll have the JRE also.
In Windows you can see if you have these installed in Programs and Features in the Control Panel.

I got mine from here.
Once again open System Properties.
Go to the Advanced tab, and click the Environment Variables button.
Under the System variables, select Path, click edit.
As we did for csc.exe add the path with the semi colon in the front if there are already paths in there.

;E:\Program Files\Java\jdk1.6.0_18\bin

OK and apply all of that.
From then on, I just stick my java files in a directory in C:\Users\Me\
This way I just run cmd and cd into my dir that has my java files and I’m ready to go.

To compile your code into a bytecode file with a .class extension…

C:\Users\Me\MyDir>javac HelloWorld.java

To run your new bytecode…

C:\Users\Me\MyDir>java HelloWorld

Details here.

Now if you want to debug your java code on the command line,
it’s a breeze because the jdb.exe is in the same directory as java.exe and javac.exe.

 

All the commands and switches for jdb are here.

The Java documentation is very good, you won’t often not be able to find answers quickly.

There are also online options

Atlassian has some very comprehensive products that may suit.

Or you could go with a very light weight option.
compilr is a good one for C#, VB and Java.

Next post on this topic we’ll go into the language details.

Cya.