I have some custom Java functions that I have developed as part of a Streaming fragment project (maintained under the project's src/main/java/ folder). How can I make these functions available for use in other Streaming fragment projects?

A custom Java function (or a set of custom Java functions) may be packaged into a *.jar file, and made available for use in other projects by your Maven repository.

First, modify the pom.xml of the project which holds the custom Java function code. In the pom.xml, replace..
 

<packaging>ep-eventflow-fragment</packaging>

..with:
 

<packaging>jar</packaging>

To the same pom.xml, also add the following:
 

<build>
    <plugins>
      <plugin> 
        <groupId>org.apache.maven.plugins</groupId> 
        <artifactId>maven-jar-plugin</artifactId> 
        <version>3.2.0</version>
        <configuration>
          <archive>
            <manifestSections>
              <manifestSection>
                <name>com/tibco/ep/sample/Hypotenuse.class</name>
                <manifestEntries>
                  <StreamBase-Adapter>False</StreamBase-Adapter>
                </manifestEntries>
              </manifestSection> 
              <manifestSection>
                <name>com/tibco/ep/sample/VarArgs.class</name>
                <manifestEntries>
                  <StreamBase-Adapter>False</StreamBase-Adapter>
                </manifestEntries>
              </manifestSection>
            </manifestSections>
          </archive>
        </configuration>
      </plugin>
    </plugins>
  </build>

..where the <manifestSection> provides the full class name for the custom Java function(s). Check the maven-jar-plugin plugin <version> value and change it to match your environment. The above example works for the 'Hypotenuse' and 'VarArgs' Java code from the "custom Java simple function" sample (under $STREAMBASE_HOME/sample/custom-java-function/).

Next, right-click on the root project folder and select Maven > Update Project, and update the project.

Next, perform a Maven clean/install. From a StreamBase command prompt (starting in the project root folder), run..
 

mvn clean install -DskipTests

This will install your custom functions jar to your Maven repository.

Now, in another project where you want to use these functions, simply add this *.jar as a dependency in the pom.xml. For example:
 

<dependency>
  <groupId>com.tibco.ep.sample</groupId>  
  <artifactId>sample_custom-java-function</artifactId>
  <version>0.0.1-SNAPSHOT</version>
</dependency>

Finally, create a StreamBase engine HOCON configuration to reference the custom functions using the CustomFunctionGroup:
 

configuration = {
  CustomFunctionGroup = {
    customFunctions = {
      hypotenuse = {
        type = "simple"
        methodName = "calculate"
        className = "com.tibco.ep.sample.Hypotenuse"
        autoArguments = true     
      }
      calchyp = {
        type = "simple"
        methodName = "calculate"
        className = "com.tibco.ep.sample.Hypotenuse"
        autoArguments = true
      }
      hypot = {
        type = "simple"
        methodName = "hypot"
        className = "java.lang.Math"
        autoArguments = true
      }
      isIn = {
        type = "simple"
        methodName = "isIn"
        className = "com.tibco.ep.sample.VarArgs"
        autoArguments = true
      }
      sumAll = {
        type = "simple"
        methodName = "sumAll"
        className = "com.tibco.ep.sample.VarArgs"
        autoArguments = true
      }
      mx = {
        type = "simple"
        methodName = "max"
        className = "java.lang.Math"
        argumentTypes = [
          { type = "double" }
          { type = "double" }
        ]
        returnType = { type = "double" }
      }      
    }
  }
}

These functions will now be available for use by your project.

 

Describes the steps needed to package a set of custom Java functions into a Maven *.jar dependency, to be used in other Streaming fragment projects.