A simple plug-in in Java
The simple plug-in sample can be found in the samples\correlator_plugin\java directory of your Apama installation.
The Java code for the SimplePlugin class contains the public static test method. (Methods that will be called from EPL code need to be public and static.)
public class SimplePlugin
{
public static final String TEST_STRING = "Hello, World";
public static String test(String arg)
{
System.out.println("SimplePlugin function test called");
System.out.println("arg = "+arg);
System.out.println("return value = "+TEST_STRING);
return TEST_STRING;
}
}
The SimplePlugin.xml file is the deployment descriptor and contains the following <plugin> stanza that illustrates how to specify the plug-in.
The SimplePlugin.mon file contains the EPL code. It imports the plug-in and calls the test method.
monitor SimplePluginTest {
// Load the plugin
import "SimplePlugin" as simple;
// To hold the return value
string ret;
string arg;
action onload() {
// Call plugin function
arg := "Hello, Simple Plugin";
ret := simple.test(arg);
// Print out return value
log "simple.test = " + ret at INFO;
log "arg = " + arg at INFO;
}
}