using java classes in your

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19/6/2014 Using Java Classes in your .NET Application - CodeProject

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Jeff Prosise on .NET

Simple Source Line Counter in

Java for Java

Introduction to Visual J# .NET

The Common LanguageRuntime (CLR) and JavaRuntime Environment (JRE)

SharpHSQL - An SQL enginewritten in C#

.NET and J2EE interoperabilityfor .Net Developers

Related Research

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In-The-Wild Testing: How toEnsure Your Apps Work in the

Real World

Developer Tips for Scanning onthe Web

Essential Keys to MobileUsability

directory. Open a command or shell window, cd to C:\ikvm\bin, and type ikvm.

If your system is operating correctly, you should see the following output:

usage: ikvm [-options] [args...] (to execute a class) or ikvm -jar [-options] [args...]

(to execute a jar file)

For Linux based systems, the setup is similar as above. This is all you need to do for running the

demo application.

Our Demo Java Business Class (JavaToNet.java)

Collapse | Copy Code

publicclassJavaToNet{ publicstaticvoidmain(String[] args)

{ System.out.println("This is a demonstration Program which\n"); System.out.println("shows the conversion of Java class to\n"); System.out.println("a .NET dll\n"); } public staticdoubleAddNumbers(doublea,doubleb){ doublec = 0; c = a + b; returnc;

} public staticdoubleSubNumbers(doublea,doubleb){ doublec = 0;

c = a - b; returnc;

} public staticdoubleMulNumbers(doublea,doubleb){ doublec = 0; c = a * b; returnc;

} public staticdoubleDivNumbers(doublea,doubleb){ doublec = 0; c = a / b; returnc;

}

}

Our Java class is very simple. It has four functions for add, subtract, multiply and divide that take

two double values and return a result. Our objective is to access these functions through our C#

application. Compile the above Java file to get the JavaToNet.class . We will use this Java class fileto generate the .NET DLL to be referenced in our C# program.

Using IKVM.NET to Convert Java Class to

.NET DLL

Copy the above Java class file (JavaToNet.class ) to the C:\ikvm\bindirectory. Now run the

following command:

This would create the JavaToNet.dll from the JavaToNet.class file. There are other command line

option for ikvmc.exe. For example: ikvmc target:exe javaToNet.class would create

an EXE and not a DLL. You can get all the options by typing ikvmc in the command line.

Setting Up Your .NET Development

Environment

1. Start by creating a C# Windows application project.

2. Drag and drop controls into the form as shown:
http://www.codeproject.com/ResearchLibrary/46/Essential-Keys-to-Mobile-Usabilityhttp://www.codeproject.com/ResearchLibrary/57/Developer-Tips-for-Scanning-on-the-Webhttp://www.codeproject.com/ResearchLibrary/18/In-The-Wild-Testing-How-to-Ensure-Your-Apps-Work-ihttp://www.codeproject.com/ResearchLibrary/56/Enterprise-Imaging-on-the-Web-A-How-To-Guide-for-Dhttp://www.codeproject.com/Articles/22560/NET-and-J-EE-interoperability-for-Net-Developershttp://www.codeproject.com/Articles/1136/SharpHSQL-An-SQL-engine-written-in-Chttp://www.codeproject.com/Articles/1825/The-Common-Language-Runtime-CLR-and-Java-Runtime-Ehttp://www.codeproject.com/Articles/1440/Introduction-to-Visual-J-NEThttp://www.codeproject.com/Tips/139036/Simple-Source-Line-Counter-in-Java-for-Javahttp://www.codeproject.com/Articles/688/Jeff-Prosise-on-NET


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3. Add the following DLLs as references to the project. Both DLLs are present in the

C:\ikvm\binfolder.

JavaToNet.dll

IKVM.GNU.Classpath.dll

4. Add the following code to the button click event of the Calculate button:


privatevoidbtnCal_Click(objectsender, System.EventArgs e){if(rdAdd.Checked == true) { txtResult.Text = Convert.ToString(JavaToNet.AddNumbers (Convert.ToDouble(txtNum1.Text),Convert.ToDouble(txtNum2.Text))); }elseif(rdSub.Checked ==true) { txtResult.Text = Convert.ToString(JavaToNet.SubNumbers (Convert.ToDouble(txtNum1.Text),Convert.ToDouble(txtNum2.Text)));

} elseif(rdMul.Checked == true) { txtResult.Text = Convert.ToString(JavaToNet.MulNumbers (Convert.ToDouble(txtNum1.Text),Convert.ToDouble(txtNum2.Text)));

} else

{ txtResult.Text = Convert.ToString(JavaToNet.DivNumbers (Convert.ToDouble(txtNum1.Text),Convert.ToDouble(txtNum2.Text)));

}}

5. Add the following usingdirective on the top of the *.csfile:


usingTimeZone = java.util.TimeZone;

6. Add the following code to the button click event of the Time Zone button.


privatevoidbtnTimeZone_Click(objectsender, System.EventArgs e){MessageBox.Show(TimeZone.getDefault().getDisplayName());}

7. Compile and run the application. The C# application would now call the AddNumbers(),

SubNumbers(), MulNumbers() and DivNumbers() functions present in the

JavaToNet.dlland return the result.

8. Click on the Time Zone button. The application accesses the java.util.TimeZone class

and displays the exact time zone of the place.


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ChayanWeb Developer

India

Chayan Ray has been working as a Technical Consultant in a CMM level 5 company in India. His

technical domain includes ASP.NET, C#, PHP, Perl, Cold Fusion, MySQL and MSSQL 2000.

Conclusion

Since these methods had originally been written in Java, IKVM.NET provides us an easy and viable

way to access those classes and methods from a .NET application. Similarly as shown above in the

Time Zone example, you can access most of the existing Java packages (e.g. java.io , java.util , etc.)

and use them in your application.

However there are certain drawbacks. IKVM.NET, while still being actively developed, has limited

support for AWT classes and hence porting Java GUI can be ruled out at present. Also some of

the default Java classes are still being ported so you might not get all the functionalities you

require. Also if your application depends on the exact Java class loading semantics, you might

have to modify it to suit your needs.

History

03-25-06 Initial publication

License

This article, along with any associated source code and files, is licensed under The Code Project

Open License (CPOL)

About the Author

Article Top
http://-/?-http://www.codeproject.com/info/cpol10.aspxhttp://www.ucancode.net/index.htmhttp://www.codeproject.com/Members/User-248385


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Vitaly Shelest 22-Jun-06 8:02

Missing file

Error Message ->IKVMC0002: Output File

is "JavaToNet.dll"

Getting errors while converting Jar to dll

using IKVM - please help!

Getting Class not found errors while

converting jar to dll using IKVM - please

help!!!!

Getting Class not found errors while

converting jar to dll using IKVM

ikmv class java to .net c#

How to use IKVM without creating dll

Thank you...

Thanks

IKVM Framework is Updated

the architecture in IKVM ?

Jar to Native Dll

Re: Jar to Native Dll

Re: Jar to Native Dll

My vote of 5

using a jar file with dependent jars

Re: using a jar file with dependent jars

Re: using a jar file with dependent jars

Has Dependent Jar files?

Problem with IKVM

Does it only work with static method

get a error that "unsupported class file

version:"

IKVM.NET violates Java and .NET

standards!
http://www.codeproject.com/Messages/1543918/IKVM-NET-violates-Java-and-NET-standards.aspxhttp://www.codeproject.com/Messages/1565636/get-a-error-that-unsupported-class-file-version.aspxhttp://www.codeproject.com/Messages/1683483/Does-it-only-work-with-static-method.aspxhttp://www.codeproject.com/Messages/2117354/Problem-with-IKVM.aspxhttp://www.codeproject.com/Messages/2603964/Has-Dependent-Jar-files.aspxhttp://www.codeproject.com/Messages/4440525/Re-using-a-jar-file-with-dependent-jars.aspxhttp://www.codeproject.com/Messages/4190250/Re-using-a-jar-file-with-dependent-jars.aspxhttp://www.codeproject.com/Messages/2781359/using-a-jar-file-with-dependent-jars.aspxhttp://www.codeproject.com/Messages/3530273/My-vote-of.aspxhttp://www.codeproject.com/Messages/3684738/Re-Jar-to-Native-Dll.aspxhttp://www.codeproject.com/Messages/3684059/Re-Jar-to-Native-Dll.aspxhttp://www.codeproject.com/Messages/3683808/Jar-to-Native-Dll.aspxhttp://www.codeproject.com/Messages/3778342/the-architecture-in-IKVM.aspxhttp://www.codeproject.com/Messages/3859236/IKVM-Framework-is-Updated.aspxhttp://www.codeproject.com/Messages/4031118/Thanks.aspxhttp://www.codeproject.com/Messages/4060917/Thank-you.aspxhttp://www.codeproject.com/Messages/4262308/How-to-use-IKVM-without-creating-dll.aspxhttp://www.codeproject.com/Messages/4283035/ikmv-class-java-to-net-csharp.aspxhttp://www.codeproject.com/Messages/4463167/Getting-Class-not-found-errors-while-converting-ja.aspxhttp://www.codeproject.com/Messages/4463168/Getting-Class-not-found-errors-while-converting-ja.aspxhttp://www.codeproject.com/Messages/4463170/Getting-errors-while-converting-Jar-to-dll-using-I.aspxhttp://www.codeproject.com/Messages/4476576/Error-Message-IKVMC-Output-File-is-JavaToNet-dll.aspxhttp://www.codeproject.com/Messages/4750117/Missing-file.aspxhttp://www.codeproject.com/script/Membership/View.aspx?mid=2648168http://www.codeproject.com/script/Membership/View.aspx?mid=3169492http://www.codeproject.com/script/Membership/View.aspx?mid=1862169http://www.codeproject.com/script/Membership/View.aspx?mid=3066546http://www.codeproject.com/script/Membership/View.aspx?mid=877304http://www.codeproject.com/script/Membership/View.aspx?mid=4187012http://www.codeproject.com/script/Membership/View.aspx?mid=7048993http://www.codeproject.com/script/Membership/View.aspx?mid=5317483http://www.codeproject.com/script/Membership/View.aspx?mid=7292947http://www.codeproject.com/script/Membership/View.aspx?mid=7597442http://www.codeproject.com/script/Membership/View.aspx?mid=248608http://www.codeproject.com/script/Membership/View.aspx?mid=7597442http://www.codeproject.com/script/Membership/View.aspx?mid=7692279http://www.codeproject.com/script/Membership/View.aspx?mid=1032729http://www.codeproject.com/script/Membership/View.aspx?mid=6547884http://www.codeproject.com/script/Membership/View.aspx?mid=5497773http://www.codeproject.com/script/Membership/View.aspx?mid=4261880http://www.codeproject.com/script/Membership/View.aspx?mid=4559750http://www.codeproject.com/script/Membership/View.aspx?mid=9658973http://www.codeproject.com/script/Membership/View.aspx?mid=9658973http://www.codeproject.com/script/Membership/View.aspx?mid=9658973http://www.codeproject.com/script/Membership/View.aspx?mid=3503712http://www.codeproject.com/script/Membership/View.aspx?mid=10567702http://www.codeproject.com/Articles/13549/Using-Java-Classes-in-your-NET-Application?fid=283780&df=90&mpp=25&noise=3&prof=False&sort=Position&view=Normal&spc=Relaxed&fr=26#xx0xxhttp://www.codeproject.com/KB/FAQs/MessageBoardsFAQ.aspxhttp://www.codeproject.com/script/Forums/Edit.aspx?fid=283780&floc=/Articles/13549/Using-Java-Classes-in-your-NET-Application


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Help regarding IKVMC tool

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