RhoConnect-Java

RhoConnect-Java library is designed for the RhoConnect Application Integration Server.

Using the RhoConnect-Java plugin, your Spring 3 MVC application's data will transparently synchronize with a mobile application built on the Rhodes framework, or any of the available RhoConnect clients.

Prerequisites

• Java (1.6)
• Maven
• Git
• rhoconnect-java RhoConnect Java plugin jar
• rhoconnect-java-api RhoConnect Java API jar

Getting started

We assume that you have a complete java end-to-end application using Spring 3.0 MVC as the front end technology and Hibernate as backend ORM. For this application we will also use Maven for build and dependency management and some database to persist the data. The database is accessed by a Data Access (DAO) layer.

Copy rhoconnect-java and rhoconnect-java-api jar files to your PC. You can also create target rhoconnect-java plugin jar from sources by cloning rhoconnect-java repository

:::term
$ git clone git@github.com:rhomobile/rhoconnect-java.git

and executing in cloned project directory the following commands:

:::term
$ mvn package

The archived rhoconnect-java-x.y.z.jar file will be created in the project java-plugin/target/ directory. The accompanying rhoconnect-java-api-x.y.z.jar file will be created in the project java-api/target/ directory.

For testing and evaluation purposes you can use RhoconnectJavaSample application as a starting point before continuing with the following steps.

Adding Dependencies to Your Maven Project

Add dependencies to your Apache Maven project object model (POM): log4j, Apache common beanutils, and Jackson JSON mapper. In the RhoconnectJavaSample application, this code is in the pom.xml file.

:::xml
<!-- Log4j -->
<dependency>
    <groupId>log4j</groupId>
    <artifactId>log4j</artifactId>
    <version>1.2.9</version>
    <type>jar</type>
    <optional>false</optional>
</dependency>
<!-- Apache Commons Beanutils and Jackson JSON Mapper required by rhoconnect-java plugin -->
<dependency>
    <groupId>commons-beanutils</groupId>
    <artifactId>commons-beanutils</artifactId>
    <version>1.8.3</version>
</dependency>
<dependency>  
    <groupId>org.codehaus.jackson</groupId>  
    <artifactId>jackson-mapper-asl</artifactId>  
    <version>1.9.0</version>  
    <type>jar</type>  
    <optional>false</optional>  
</dependency>

You must also add the rhoconnect-java and rhoconnect-java-api jars to your Maven project. At this moment they are not available in Maven public repositories and you need install the jar manually into your Maven's local repository.

:::term
$ mvn install:install-file -Dfile=/path-to-jar/rhoconnect-java-api-1.0.0.jar -DgroupId=com.msi.rhoconnect.api \
  -DartifactId=rhoconnect-java-api -Dversion=1.0.0 -Dpackaging=jar
$ mvn install:install-file -Dfile=/path-to-jar/rhoconnect-java-1.0.2.jar \
  -DgroupId=com.rhomobile.rhoconnect  -DartifactId=rhoconnect-java -Dversion=1.0.2 -Dpackaging=jar

Now, the rhoconnect-java jar library is included into your Maven local repository. In the RhoconnectJavaSample application, you would add this code to the pom.xml file.

:::xml
<!-- Rhoconnect-java plugin -->
<dependency>
	<groupId>com.rhomobile.rhoconnect</groupId>
	<artifactId>rhoconnect-java</artifactId>
	<version>1.0.1</version>
	<type>jar</type>
</dependency>
<!-- Rhoconnect-java-api and its dependencies -->
<dependency>
    <groupId>com.msi.rhoconnect.api</groupId>
    <artifactId>rhoconnect-java-api</artifactId>
    <version>1.0.0</version>
    <type>jar</type>
</dependency>
<dependency>
  <groupId>com.sun.jersey</groupId>
  <artifactId>jersey-bundle</artifactId>
  <version>1.17</version>
</dependency>
<dependency>
  <groupId>com.googlecode.json-simple</groupId>
  <artifactId>json-simple</artifactId>
  <version>1.1.1</version>
</dependency>

Updating Your Servlet XML Configuration File

Update your servlet xml configuration file to include rhoconnect-java metadata: the packages, converters, and beans. In the RhoconnectJavaSample, the following code is added to src/main/webapp/WEB-INF/spring-servlet.xml file.

:::xml
<!-- rhoconnect-java plugin packages -->
<context:component-scan base-package="com.rhomobile.rhoconnect.controller" /> 

<!-- rhoconnect-java plugin converters -->
<bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
 	<property name="order" value="1" />
 	<property name="messageConverters">
     	<list>
         	<ref bean="stringHttpMessageConverter"/>
         	<ref bean="jsonConverter" />
     	</list>
 	</property>
</bean>
<bean id="jsonConverter" class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter">
 	<property name="supportedMediaTypes" value="application/json" />
</bean>
<bean id="stringHttpMessageConverter" class="org.springframework.http.converter.StringHttpMessageConverter">
</bean>
<bean id="restTemplate" class="org.springframework.web.client.RestTemplate">
 	<property name="messageConverters">
     	<list>
         	<ref bean="jsonConverter" />
         	<ref bean="stringHttpMessageConverter"/>
     	</list>
 	</property>
</bean>    

<!-- rhoconnect-java plugin beans -->
<bean id="dispatcher" class = "com.rhomobile.rhoconnect.RhoconnectDispatcher"></bean>
<bean id="rhoconnectClient" class = "com.rhomobile.rhoconnect.RhoconnectClient" init-method="setAppEndpoint" >
 	<property name="endpointUrl" value="your_rhoconnect_server_url" />
 	<property name="appEndpoint" value="your_spring_app_url" />
 	<property name="apiToken" value="my-rhoconnect-token" />
</bean>

<!--The following bean handles the application's authentication routine and should be implemented by you -->
<bean id="authenticate" class = "com.rhomobile.contact.ContactAuthenticate" />

The setAppEndpoint method in the rhoconnectClient bean in the above code sample is a main point in establishing the communication link between the Rhoconnect server and the Spring 3 MVC application. It has the following properties that you need to configure.

endpointUrl	rhoconnect server's url, for example http://localhost:9292
appEndpoint	your Spring 3 MVC app url, for example http://localhost:8080/contacts
apiToken	rhoconnect server's api_token, for example my-rhoconnect-token

The authenticate bean will be called by rhoconnect server to authenticate users, and has to implement Rhoconnect interface provided by rhoconnect-java plugin:

:::java
package com.rhomobile.rhoconnect;
import java.util.Map;

public interface Rhoconnect {
    String authenticate(String userName, String password, Map<String, Object> attributes);
}

For example:

:::java
package com.rhomobile.contact;

import java.util.Map;
import org.apache.log4j.Logger;
import com.rhomobile.rhoconnect.Rhoconnect;

public class ContactAuthenticate implements Rhoconnect {
    private static final Logger logger = Logger.getLogger(ContactAuthenticate.class);

    @Override
    public String authenticate(String login, String password, Map<String, Object> attributes) {
		logger.debug("ContactAuthenticate#authenticate: implement your authentication code!");
        // TODO: your authentication code goes here ...		
		// Return null value if authentication fails.

		// Otherwise, returned value is data partitioning: i.e. user name for filtering data on per user basis
		//return login;

		// But if you want your data to be partitioned by ‘app’ (i.e. the data will be shared among all users),
        // you should return string "app": it will instruct Rhoconnect to partition the data accordingly.
        return "app";
    }
}

Establishing communication from the RhoConnect server to java back-end application

You need to establish communication from the RhoConnect instance to your java back-end application by mixing RhoconnectResource interface in your data access (DAO) service class:

:::java
package com.rhomobile.rhoconnect;

import java.util.Map;

public interface RhoconnectResource {
	Map<String, Object> rhoconnectQuery(String partition);
	Integer rhoconnectCreate(String partition, Map<String, Object> attributes);
	Integer rhoconnectUpdate(String partition, Map<String, Object> attributes);
	Integer rhoconnetDelete(String partition, Map<String, Object> attributes);
}

To help rhoconnect-java plugin correctly do mapping of model name to service bean you should take into account the following conventions:

• Name of the DAO service bean (class) should be model name followed by ServiceImpl suffix (i. e. ContactServiceImpl for model Contact)
• Service bean should be auto-wired into corresponding controller via @Autowired annotation

Data partitioning in your code should be based on filtering data for unique user (i.e. your user name) or per application (shared dataset for all users). For more information about RhoConnect partitions, please refer to the RhoConnect docs.

Establishing communication from java back-end application to the RhoConnect server

You also must to establish the communication from your java back-end application to the RhoConnect instance by auto-wiring RhoconnectClient bean into your DAO service class and inserting notifications hooks into data access (create/update/delete) methods. RhoconnectClient bean is provided by rhoconnect-java plugin and responds to the following methods you have to call:

• boolean notifyOnCreate(String sourceName, Object objId, Object object)
• boolean notifyOnUpdate(String sourceName, Object objId, Object object)
• boolean notifyOnDelete(String sourceName, Object objId)

Example for RhoconnectJavaSample application:

:::java
package com.rhomobile.contact.service;

import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.apache.commons.beanutils.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import com.rhomobile.contact.dao.ContactDAO;
import com.rhomobile.contact.form.Contact;

import com.rhomobile.rhoconnect.RhoconnectClient;
import com.rhomobile.rhoconnect.RhoconnectResource;

@Service
public class ContactServiceImpl implements ContactService, RhoconnectResource {
    //private static final Logger logger = Logger.getLogger(ContactServiceImpl.class);

    @Autowired
    private ContactDAO contactDAO;
    @Autowired
    private RhoconnectClient client;
    private static final String sourceName  = "Contact"; // name of DAO model

    @Transactional
    public int addContact(Contact contact) {
        int id = contactDAO.addContact(contact);
        client.notifyOnCreate(sourceName, Integer.toString(id), contact);
        return id;
    }

    @Transactional
    public void updateContact(Contact contact) {
        contactDAO.updateContact(contact);
        client.notifyOnUpdate(sourceName, Integer.toString(contact.getId()), contact);       
    }

    @Transactional
    public void removeContact(Integer id) {
        contactDAO.removeContact(id);
        client.notifyOnDelete(sourceName, Integer.toString(id));
    }

    @Transactional
    public List<Contact> listContact() {
        return contactDAO.listContact();
    }

    @Transactional
    public Contact getContact(Integer id) {
        return contactDAO.getContact(id);
    }

    @Override
    @Transactional
    public Map<String, Object> rhoconnectQuery(String partition) {
        Map<String, Object> h = new HashMap<String, Object>();
        List<Contact> contacts =  listContact();

        Iterator<Contact> it = contacts.iterator( );
        while(it.hasNext()) {
            Contact c =(Contact)it.next();
            h.put(c.getId().toString(), c);
        }
        return h;
    }

    @Override
    @Transactional
    public Integer rhoconnectCreate(String partition, Map<String, Object> attributes) {
        Contact contact = new Contact();
        try {
            BeanUtils.populate(contact, attributes);
            int id = addContact(contact);
            return id;
        } catch(Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    @Override
    @Transactional
	public Integer rhoconnectUpdate(String partition, Map<String, Object> attributes) {
        Integer id = Integer.parseInt((String)attributes.get("id"));
        Contact contact = getContact(id);
        try {
            BeanUtils.populate(contact, attributes);
            updateContact(contact);
            return id;
        } catch(Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    @Override
    @Transactional
    public Integer rhoconnetDelete(String partition, Map<String, Object> attributes) {
        String objId = (String)attributes.get("id");
        Integer id = Integer.parseInt(objId);
        removeContact(id);       
        return id;
    }
 }

Click here to download full source code of Contact manager application with rhoconnect-java plugin.

RhoConnect-Java-API

The rhoconnect-java project contains java-api module that provides Java API to all resources available in Rhoconnect. The rhoconnect-java-apiis a generic Java library for communicating with RhoConnect RESTful API and might be used to implement java client apps or components of back-end servers. This library also is used by RhoConnect-Java plugin to directly access RhoConnect resources.

The library has the following dependencies:

• jersey java
• json-simple

Sample of Java RhoConnect client app

:::java
import com.msi.rhoconnect.api.SystemResource;
import com.msi.rhoconnect.api.UserResource;
import com.sun.jersey.api.client.ClientResponse;
import org.json.simple.JSONArray;
import org.json.simple.JSONValue;

public class JavaClient {
	static String URL = "http://localhost:9292";

	public static void main(String[] args) {
		try {
			ClientResponse response = SystemResource.login(URL, "");
			if(response.getStatus() == 200) {
				String token = response.getEntity(String.class);
				System.out.println("Login to server. Got API token: " + token);

				// List users registered with this RhoConnect application
				response = UserResource.list(URL, token);
				JSONArray users = (JSONArray)JSONValue.parse(response.getEntity(String.class));
				System.out.println(users);

				// Create "testuser" in this RhoConnect application
				response = UserResource.create(URL, token, "testuser", "password");

				// Make sure that 'testuser' is registered
				response = UserResource.list(URL, token);
				users = (JSONArray)JSONValue.parse(response.getEntity(String.class));
				if(users.contains("testuser")) 
					System.out.println("User 'testuser' created");
				System.out.println(users);

				// ....

				// Delete "testuser" from this rhoconnect app
				response = UserResource.delete(URL, token, "testuser");
				if (response.getStatus() == 200) 
					System.out.println("User 'testuser' deleted");
			}
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}		
	}
}

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Created and maintained by Alexander Babichev.

Released under the MIT License.