APIM manage workflow with multiple roles APIM 3.0.0 per API based subscription workflow Logging internal HTTP requests Log APIM analytics events to a file Monetization and sample with WSO2 API Manager 2.6.0 Share application and subscription among a set of specific groups or roles WSO2 APIM Correlating analytics event with correlationID APIM analytics distinguish production and sandbox traffic APIM 2.x.x analytics internal and analytics tuneup Configure APIM(Next release) Key Manager User stores APIM(Next release) working with key manager DAS 3.x Parse system variables to Spark Context Revoke OAuth application In APIM 2.1.0 Next WSO2 APIM powered by WSO2 Ballerina Configure WSO2 APIM Analytics on Cluster environment Configure WSO2 DAS 3.1.0 for WSO2 APIM 2.0.0 Analytics WSO2 APIM publishing custom statistics WSO2 APIM Error codes Working with WSO2 message tracer Use DAS admin service to query using Spark SQL Configure WSO2 APIM Analytics using XML WSO2 APIM Generating and Retrieving Custom Statistics Understanding WSO2 APIM Statistics Model Publishing WSO2 APIM 1.10.x Runtime Statistics to DAS with RDBMS Publishing_APIM_1100_Runtime_Statistics_to_DAS Aggregate functions with WSO2 DAS REST API Create a cApp for WSO2 DAS Debugging WSO2 Products using OSGI console. Publishing APIM Runtime Statistics to DAS Deploy cApp on WSO2 DAS How to configure and start the Accumulo minicluster How to setup DNS server on Ubuntu and Ubuntu server How to use Java Reflection how to install apache web server on ubuntu and ubuntu server How to install Mail server on Ubuntu and Ubuntu server How to install squirrelmail webmail client on Ubuntu and Ubuntu Server Pass and return String value to JNI method Pass and return numeric value to JNI method Calling a C Function from the Java Programming Language using JNI AXIS 2 Sample web service Client with maven and eclipse How to setup AXIS 2 with Apache Tomcat AXIS 2 Sample web service with maven and eclipse Robot framework Sample with Selenium Robot framework Custom Library Sample Behaviour-Driven Development with JBehave and Eclipse Play Audio with Netbeans and linking with LibVLC Implement LibVLC based player with QT-part2 Simple Audio playing sample with LibVLC How to install LibVLC on Ubuntu Implement LibVLC based player with QT-part1
Calling a C Function from the Java Programming Language using JNI
  • Suppose you have sample c code which do some use full function and you don’t like to implement it in java again.
  • The solution is java native interface (JNI). It let you to invoke C/C++ function within the java code.
  • Suppose this is the C function u need to invoke.
        void greeting()
        {
            printf("Hello Native World!\n");
        }
    
  • But before it used in java this c code should be define as native method.
  • For eases of use let’s define the how we going to use this function in java.
        class HelloNative{
            public static native void greeting();
    
            static{
                System.loadLibrary("HelloNative");
            }
        }
    
  • HellowNative is like interface in java. Then JVM load the native library when it use this class.
  • To use HelloNative.java "HelloNative" native library should be compatible with HelloNative.java. To implement compatible library we implement compatible C file.
  • To do this we generate header file based on this.
  • Compile the HelloNative.java
        javac HelloNative.java
    
  • Generate header
        javah HelloNative
    
  • Implement the C function
        #include "HelloNative.h"
        #include 
    
        JNIEXPORT void JNICALL Java_HelloNative_greeting (JNIEnv *env, jclass cl)
        {
            printf("Hello Native World!\n");
        }
    
  • Generate Linkied library
        //on Cygwin programming environment in windows
        gcc -mno-cygwin -D __int64="long long" -I JAVA_HOME/include/ -I JAVA_HOME/include/win32 -shared -Wl,--add-stdcall-alias -o HelloNative.dll HelloNative.c
    
        // Gnu C compiler on Linux
        gcc -fPIC -I JAVA_HOME/include -I JAVA_HOME/include/linux -shared -o libHelloNative.so HelloNative.c
    
    
        //With tSun compiler under the Solaris Operating System
        cc -G -I JAVA_HOME/include -I JAVA_HOME/include/solaris -o libHelloNative.so HelloNative.c
    
        //in Microsoft C++ compiler on Windows
        cl -I JAVA_HOME\include -I JAVA_HOME\include\win32 -LD HelloNative.c -FeHelloNative.dll
    
    
  • Implement the test class
        class HelloNativeTest{
            public static void main(String[] args){
                HelloNative.greeting();
            }
        }
        
  • Run the test class
        javac HelloNativeTest.java
        java HelloNativeTest
    
  • Get the source code here.

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