C # making COM components: How Java calls. NET DLLs

This article will give you a detailed introduction to Java calling. NET DLLs to achieve special customer requirements: "You must use the. NET-written DLL encryption mechanism that you have provided in your Java project!" ”

Environment and tools:

.net framework 3.5 C #

Java jdk1.5, Tomcat 5.5

Jacob-1.15-m3

Implementation example:

C # Production of COM components

Create a new class item, name testcom

Code

Using System; Using System.Collections.Generic; Using System.Linq; Using System.Text; Using System.Runtime.InteropServices; Namespace testcom {[Guid (' e9bcf867-cd81-40d0-9591-ed28d1ed2b53 ')] public interface Iencrypt {[DispId (1)] String Getencrypt (String str,string str2); } [Guid ("33a6e58d-e1f5-4b53-b2e2-03b9f8ba2fad"), ClassInterface (ClassInterfaceType.None)] public class Encrypt:iencrypt {public Encrypt () {} public string Getencrypt (String str,string str2) { Return "test" +str+ "" +STR2; } } }

Open the Project--> Properties menu in the Application tab and open Assembly information to select Make Assembly com-visible. Switch to the Build tab to select the Register for COM Interop item.

Build of GUIDs: Opens visual Studio command Prompt Input guidgen command to pull up tools. Type Select registry Format, click the new Guid, and then copy it.

[DispId (1)] is the identity of the function. If you have more than one function, add [DispId (2)] to the front of the function, [DispId (3)] ...

TestCom.dll and testcom.tlb are generated in the debug directory of the compiler

To register the COM method manually:

Open Visual Studio command prompt into the debug directory and run the command registration: RegAsm Testcom.dll/tlb:testcom.tlb

Second, Java invoke COM

Deploy Jacob

Introducing Jacob.jar in the development environment

Copy the Jacob-1.15-m3-x86.dll file to the C:\Windows\System32 directory and, if it is a Web application, copy it to the Jdk1.5.0_16\bin directory (the bin directory under the JDK installation directory)

Java calling code

Code

Import com.jacob.activeX.ActiveXComponent; Import Com.jacob.com.ComThread; Import Com.jacob.com.Dispatch; Import com.jacob.com.Variant; public class Test { /** * @param args * * public static void Main (string[] args) { TODO auto-generated Method Stub Try { Activexcomponent dotnetcom = null; dotnetcom = new Activexcomponent ("Testcom.encrypt"); Variant var = dispatch.call (dotnetcom, "Getencrypt", "elder brother is the first parameter", "elder brother is the second parameter"); String str = var.tostring (); return value catch (Exception ex) { Ex.printstacktrace (); } } }

This completes the Java call to the. NET DLL Method!