[:Outline:]
For running an agent, you must launch this agent on the runtime environment. This document explains how to launch an agent on the Janus platform from the command line.
Three methods could be used for launching an agent with Janus:
- Using the provided janus command-line tool;
- Using the standard java method;
- Using Maven execution plugin.
The SARL project provides a command-line tool for launching agents on the Janus runtime environment.
You could download this command line tool, named "janus" on the downloading page of SARL.
For launching an agent, you must launch the command-line tool with the fully-qualified name of the agent as parameter, [:janusagent:] in the following example.
[:januscmd](janus) [:janusagent](myapp.MyAgent)
The janus command-line tool provides options that will enable you to tune the launching configuration:
[:januscmd!] --help
One of the command-line options that is usually mandatory is the :janusjaroption option, which enables you to specify the jar files that contains your application:
[:januscmd!] [:janusjaroption!] path/to/myapp.jar [:janusagent!]
If the [:januscmd:] script indicates to you an error "agent not found", most of the time it is because your application's jar file is not on the class path. The [:janusjaroption!] option becomes mandatory for specifying the jar file.
The Janus platform provides a [:bootclass:] class. For launching the platform, you must execute this boot class in a Java Virtual Machine.
The typical command line is:
java [:cpcli](-cp) [:jarfile](app.jar) [:fullbootclass]{io.janusproject.[:bootclass](Boot)}
[:Fact:](io.janusproject.Boot)
The option [:cpcli:] specifies the Jar file that contains the compiled classes. The given [:jarfile:] file is a Jar file that is containing the Janus platform, the SARL libraries, and the application classes. The last argument is the fully qualified name of the booting class of Janus: [:fullbootclass:]
The example given in the previous section causes an error. Indeed, it is mandatory to specify the fully qualified name of the agent to launch:
java -cp app.jar io.janusproject.Boot myapp.MyAgent
The Janus platform allows to start only one agent from the command line. If you want to start a collection of agents, you must select one of the following approaches:
- launch a separate Janus platform instance for each agent, or
- launch an agent that is spawning the other agents.
In the previous section, we assume that all the application binary files are contained into the [:jarfile:] file.
You may replace the [:jarfile:] in the previous command lines by the classpath that is containing all the jar files required for running your application, including the Janus jar file(s):
java -cp /path/to/myapplication.jar:/path/to/[:janusjarfile](io.janusproject.kernel-<version>-with-dependencies.jar) io.janusproject.Boot myapp.MyAgent
The [:janusjarfile:] file may be dowloaded from the Janus website
You may also create the [:jarfile:] file with Maven by using the assembly plugin for creating a jar file with all the dependencies inside.
The Janus platform provides a collection of command line options. For obtaining the list of these options, you should type:
java -cp app.jar io.janusproject.Boot --help
Maven provides a plugin for launching an application after automatically building the application's classpath. This plugin may be used for launching an agent.
Based on the fact that the Janus platform provides a [:bootclass:] class for launching itself, you may use the Maven execution plugin for classing this booting class.
The typical command line is:
mvn exec:exec [:mavencliexec](-Dexec.executable)=java [:mavencliargs](-Dexec.args)="-cp %classpath io.janusproject.Boot"
The option [:mavencliexec:] specifies the Java executable.
The option [:mavencliargs:] contains the command line arguments to pass to Java.
The first argument is the classpath of the project. You must not change %classpath because it will be dynamically
replaced by the Maven plugin.
The example given in the previous section causes an error. Indeed, it is mandatory to specify the fully qualified name of the agent to launch:
mvn exec:exec -Dexec.executable=java -Dexec.args="-cp %classpath io.janusproject.Boot <qualified_name_of_the_agent>"
The Janus platform allows to start only one agent from the command line. If you want to start a collection of agents, you must select one of the following approaches:
- launch a separate Janus platform instance for each agent, or
- launch an agent that is spawning the other agents.
The Janus platform provides a collection of command line options. For obtaining the list of these options, you should type:
mvn exec:exec -Dexec.executable=java -Dexec.args="-cp %classpath io.janusproject.Boot --help"
In the next section, we will learn how to launch your SARL project from a Java program.