Chapter 5. Examples

This chapter demonstrates the use of AMQ JMS Pool through example programs.

5.1. Prerequisites

5.2. Establishing a connection

This example creates a new connection pool, binds it to a connection factory, and uses the pool to create a new connection.

Example: Establishing a connection - Connect.java

package net.example;

import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import org.apache.qpid.jms.JmsConnectionFactory;
import org.messaginghub.pooled.jms.JmsPoolConnectionFactory;

public class Connect {
    public static void main(String[] args) throws Exception {
        if (args.length != 1) {
            System.err.println("Usage: Connect <connection-uri>");
            System.exit(1);
        }

        String connUri = args[0];

        ConnectionFactory factory = new JmsConnectionFactory(connUri);
        JmsPoolConnectionFactory pool = new JmsPoolConnectionFactory();

        try {
            pool.setConnectionFactory(factory);

            Connection conn = pool.createConnection();

            conn.start();

            try {
                System.out.println("CONNECT: Connected to '" + connUri + "'");
            } finally {
                conn.close();
            }
        } finally {
            pool.stop();
        }
    }
}

5.3. Configuring the pool

This example demonstrates setting connection and session configuration options.

Example: Configuring the pool - ConnectWithConfiguration.java

package net.example;

import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import org.apache.qpid.jms.JmsConnectionFactory;
import org.messaginghub.pooled.jms.JmsPoolConnectionFactory;

public class ConnectWithConfiguration {
    public static void main(String[] args) throws Exception {
        if (args.length != 1) {
            System.err.println("Usage: ConnectWithConfiguration <connection-uri>");
            System.exit(1);
        }

        String connUri = args[0];

        ConnectionFactory factory = new JmsConnectionFactory(connUri);
        JmsPoolConnectionFactory pool = new JmsPoolConnectionFactory();

        try {
            pool.setConnectionFactory(factory);

            // Set the max connections per user to a higher value
            pool.setMaxConnections(5);

            // Create a MessageProducer for each createProducer() call
            pool.setUseAnonymousProducers(false);

            Connection conn = pool.createConnection();

            conn.start();

            try {
                System.out.println("CONNECT: Connected to '" + connUri + "'");
            } finally {
                conn.close();
            }
        } finally {
            pool.stop();
        }
    }
}

5.4. Running the examples

To compile and run the example programs, use the following procedure.

Procedure

  1. Create a new project directory. This is referred to as <project-dir> in the steps that follow.

  2. Copy the example Java listings to the following locations: 

    <project-dir>/src/main/java/net/example/Connect.java
<project-dir>/src/main/java/net/example/ConnectWithConfiguration.java

  3. Use a text editor to create a new <project-dir>/pom.xml file. Add the following XML to it: 

    <project>
  <modelVersion>4.0.0</modelVersion>

  <groupId>net.example</groupId>
  <artifactId>example</artifactId>
  <version>1.0.0-SNAPSHOT</version>

  <dependencies>
    <dependency>
      <groupId>org.messaginghub</groupId>
      <artifactId>pooled-jms</artifactId>
      <version>1.0.1.redhat-00002</version>
    </dependency>
    <dependency>
      <groupId>org.apache.qpid</groupId>
      <artifactId>qpid-jms-client</artifactId>
      <version>0.34.0.redhat-00002</version>
    </dependency>
  </dependencies>
</project>

  4. Change to the project directory and use the mvn command to compile the program. 

    mvn clean package dependency:copy-dependencies -DincludeScope=runtime -DskipTests

    The addition of dependency:copy-dependencies results in the dependencies being copied into the target/dependency directory.

  5. Use the java command to run the program.

    On Linux or UNIX: 

    java -cp "target/classes:target/dependency/*" net.example.Connect amqp://localhost

    On Windows: 

    java -cp "target\classes;target\dependency\*" net.example.Connect amqp://localhost

These sample commands run the Connect example. To run another example, replace Connect with the class name of your desired example.

Running the Connect example on Linux results in the following output: 

$ java -cp "target/classes:target/dependency/*" net.example.Connect amqp://localhost
CONNECT: Connected to 'amqp://localhost'