onvif backchannel java

ONVIF Backchannel in Java

Introduction

ONVIF (Open Network Video Interface Forum) is a global standard for the interface of physical IP-based security products, such as IP cameras and video encoders. The backchannel feature in ONVIF allows bidirectional communication between an ONVIF client and an ONVIF device. In this article, we will explore how to implement the ONVIF backchannel in Java.

Prerequisites

To follow along with the code examples in this article, you will need the following:

• Java Development Kit (JDK) installed on your machine
• Apache CXF library for implementing web services in Java
• Apache Maven for managing dependencies

Implementation

Step 1: Set up the Maven project

First, let's set up a Maven project to manage our dependencies. Create a new directory for your project and navigate to it in the terminal. Then, run the following command to create a new Maven project:

mvn archetype:generate -DgroupId=com.example -DartifactId=onvif-backchannel -DarchetypeArtifactId=maven-archetype-quickstart -DinteractiveMode=false

This will create a new Maven project with the specified Group ID and Artifact ID.

Step 2: Add dependencies

Open the pom.xml file in your project and add the following dependencies:

<dependencies>
    <dependency>
        <groupId>org.apache.cxf</groupId>
        <artifactId>cxf-rt-frontend-jaxws</artifactId>
        <version>3.4.4</version>
    </dependency>
    <dependency>
        <groupId>org.apache.cxf</groupId>
        <artifactId>cxf-rt-transports-http-jetty</artifactId>
        <version>3.4.4</version>
    </dependency>
</dependencies>

These dependencies are required to implement the ONVIF backchannel using Apache CXF.

Step 3: Create ONVIF service interface

Create a new Java interface OnvifService in the src/main/java/com/example directory with the following code:

package com.example;

import javax.jws.WebMethod;
import javax.jws.WebService;

@WebService
public interface OnvifService {

    @WebMethod
    String hello(String name);

    // Add more methods as needed
}

This interface declares a simple method hello that takes a name parameter and returns a greeting message.

Step 4: Implement the ONVIF service

Create a new Java class OnvifServiceImpl in the same directory with the following code:

package com.example;

import javax.jws.WebService;

@WebService(endpointInterface = "com.example.OnvifService")
public class OnvifServiceImpl implements OnvifService {

    @Override
    public String hello(String name) {
        return "Hello, " + name + "!";
    }

    // Implement more methods as needed
}

This class implements the OnvifService interface and provides the implementation for the hello method.

Step 5: Set up the server

Create a new Java class OnvifServer in the same directory with the following code:

package com.example;

import org.apache.cxf.jaxws.JaxWsServerFactoryBean;

public class OnvifServer {

    public static void main(String[] args) {
        String address = "http://localhost:8080/onvif";
        JaxWsServerFactoryBean factory = new JaxWsServerFactoryBean();
        factory.setServiceClass(OnvifService.class);
        factory.setServiceBean(new OnvifServiceImpl());
        factory.setAddress(address);
        factory.create();
        System.out.println("Server started at " + address);
    }
}

This class sets up a CXF server and publishes the OnvifService implementation at the specified address.

Step 6: Test the server

Now, let's test our server implementation. Create a new Java class OnvifClient in the same directory with the following code:

package com.example;

import org.apache.cxf.jaxws.JaxWsProxyFactoryBean;

public class OnvifClient {

    public static void main(String[] args) {
        String address = "http://localhost:8080/onvif";
        JaxWsProxyFactoryBean factory = new JaxWsProxyFactoryBean();
        factory.setServiceClass(OnvifService.class);
        factory.setAddress(address);
        OnvifService service = (OnvifService) factory.create();
        String response = service.hello("John");
        System.out.println(response);
    }
}

This class creates a CXF client and invokes the hello method on the server. It then prints the response received from the server.

Step 7: Run the server and client

To run the server, execute the main method in the OnvifServer class. This will start the server at http://localhost:8080/onvif.

To test the server, execute the main method in the OnvifClient class. This will send a request to the server and print the response received.