Have you ever had the need for Java\/.NET Integration ?
\nAlthough the main approach is web services interop, sometimes it’s necessary to do some lower level integration.
\nFor example if you have a neat java library for instance for logging purposes which is tightly integrated in your application.<\/p>\n
Why not use it within your .NET application as well ? <\/p>\n
With VC++.NET and Java Native Interface (JNI) it’s not that complicated.
\nJust load the Java VM into the .NET process and call the Java methods with the help of unmanaged C++.<\/p>\n
Below you can see an example of how to call the method which resides in C:\\temp\\mylogger.jar and is part of the package net.pleus. The class uses log4j.<\/p>\n \/\/ configure Java VM JavaVMInitArgs vm_args;<\/p>\n vm_args.version = JNI_VERSION_1_4; \/\/ load Java VM \/\/ find class and method \/\/ call method \/\/ cleanup The technology stack could be as follows:<\/p>\n Managed Code (C#, VB.NET) -> Hybrid C++.NET and JNI -> Java<\/p>\n I tried it out. It works very well (and fast). Have you ever had the need for Java\/.NET Integration ? Although the main approach is web services interop, sometimes it’s necessary to do some lower level integration. For example if you have a neat java library for instance for logging purposes which is tightly integrated in your application. Why not use it within your .NET … Continue reading VC++.NET – The Glue To Integrate .NET and Java<\/span><\/a><\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[22],"class_list":["post-20","post","type-post","status-publish","format-standard","hentry","category-uncategorized","tag-c"],"_links":{"self":[{"href":"https:\/\/www.pleus.net\/blog\/index.php?rest_route=\/wp\/v2\/posts\/20","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.pleus.net\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.pleus.net\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.pleus.net\/blog\/index.php?rest_route=\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.pleus.net\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=20"}],"version-history":[{"count":2,"href":"https:\/\/www.pleus.net\/blog\/index.php?rest_route=\/wp\/v2\/posts\/20\/revisions"}],"predecessor-version":[{"id":367,"href":"https:\/\/www.pleus.net\/blog\/index.php?rest_route=\/wp\/v2\/posts\/20\/revisions\/367"}],"wp:attachment":[{"href":"https:\/\/www.pleus.net\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=20"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.pleus.net\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=20"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.pleus.net\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=20"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\n
\nboolean MyLogger.log(String name)<\/b>
\n<\/font><\/p>\n
\n#include “jni.h” \/\/ included in the jdk, link to jvm.lib as well<\/p>\n
\nJavaVMOption options[3];
\noptions[0].optionString = “-Djava.compiler=NONE”;
\noptions[1].optionString = “-Djava.class.path=C:\\\\temp\\\\mylogger.jar;C:\\\\temp\\\\log4j.jar”;
\noptions[2].optionString = “-verbose:jni”;<\/p>\n
\nvm_args.options = options;
\nvm_args.nOptions = 3;
\nvm_args.ignoreUnrecognized = JNI_FALSE;<\/p>\n
\nJavaVM* jvm;
\nJNIEnv* env;
\nJNI_CreateJavaVM(&jvm,(void **)&env, &vm_args);<\/p>\n
\njclass cls = env->FindClass(“net\/pleus\/MyLogger”);
\njmethodID mid = env->GetStaticMethodID(cls,”log”,”(Ljava\/lang\/String;)Z”);<\/p>\n
\njstring name = env->NewStringUTF(“my message”);
\nbool res = env->CallStaticObjectMethod(cls,mid,name);<\/p>\n
\njvm->DestroyJavaVM();
\n<\/font><\/p>\n
\nThe most difficult thing is to perform the type conversions and code the cumbersome signature descriptions.
\nThe other way round (call .NET from Java) is also possible though it’s a little bit trickier.<\/p>\n","protected":false},"excerpt":{"rendered":"