POJO Injection

@Resource

Use @Resource to specify the attribute where dependency injection should occur.

In this example we want to inject EmployeeManager to EmployeeServiceImpl class:

//EmployeeServiceImpl.java

@Resource
private EmployeeManager employeeManager;

XML Configuration

There is only little XML Configuration needed. The file must be placed in the META-INF directory! For example resources.xml

<resources xmlns="http://simject.org/xml/ns/resources"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://simject.org/xml/ns/resources 
  http://simject.org/xml/ns/resources/resources_1_0.xsd"
  version="1.0">

  <resource type="org.simject.demo.service.EmployeeService"
    target="org.simject.demo.service.impl.EmployeeServiceImpl" />
  <resource type="org.simject.demo.business.EmployeeManager" />

</resources>

type specifies the class or interface of the resource. If it is an interface you have to specify the implementation in the target attribute.

The SimFactory

To use the configured resources you need the central class in simject: the SimFactory:

SimFactory factory = new SimFactory("resources.xml");
EmployeeService service = factory.getResource(EmployeeService.class);
Employee employee = new Employee();
employee.setName("Simon Martinelli");
service.insertEmployee(employee);
System.out.println(service.listEmployees());

JPA Injection

To simplify the use of JPA you can specify an EntityManger as a resource:

//EmployeeManager.java

@Resource
private EntityManager em;

XML Configuration

In the XML configuration you can specify the EntityManager and you also can define properties for the EntityManger:

<resource type="javax.persistence.EntityManager" name="org.simject.demo">
  <property name="hibernate.connection.driver_class" value="com.mysql.jdbc.Driver" />
  <property name="hibernate.connection.username" value="root" />
  <property name="hibernate.connection.password" value="root" />
  <property name="hibernate.connection.url" value="jdbc:mysql://localhost/demo" />
  <property name="hibernate.format_sql" value="true" />
  <property name="dialect" value="org.hibernate.dialect.MySQLDialect" />
  <property name="hibernate.hbm2ddl.auto" value="create-drop" />
</resource>

persistence.xml

The persistence.xml will then look as follow:

<persistence version="1.0"
  xmlns="http://java.sun.com/xml/ns/persistence" 
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://java.sun.com/xml/ns/persistence 
  http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd">
  
  <persistence-unit name="org.simject.demo" transaction-type="RESOURCE_LOCAL">
    <provider>org.hibernate.ejb.HibernatePersistence</provider>
    <class>org.simject.demo.model.Employee</class>
    <exclude-unlisted-classes />
  </persistence-unit>
</persistence>

Moving the properties to the resource config file will simplify the use of this persistence-unit in different environments.

Remoting

Remoting in simject is straight forwared as well.

Client

On the client side you have to define the URL of the server resource:

<resource type="org.simject.demo.service.EmployeeService"
  target="xml:http://localhost:8080/simject-demo-server/remote/org.simject.demo.service.EmployeeService" />

Protocol

By adding either xml: or bin: you can choose between XML or binary serialization.

After this prefix http://localhost:8080/simject-demo-server/remote defines the servlet listening to the requests and /org.simject.demo.service.EmployeeService ist simply the type of the requested resource.

Server

On the server side you need org.simject.remote.server.SimServerServlet which dispatches all the requests and calls the method on the requested resource.

Here an example web.xml:

<web-app id="WebApp_ID" version="2.5" xmlns="http://java.sun.com/xml/ns/j2ee"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee 
  http://java.sun.com/xml/ns/j2ee/web-app_2_5.xsd">

  <display-name>simject demo server</display-name>
  <servlet>
    <servlet-name>remote</servlet-name>
    <servlet-class>org.simject.remote.server.SimServerServlet</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>remote</servlet-name>
    <url-pattern>/remote/*</url-pattern>
  </servlet-mapping>
  <context-param>
    <param-name>simjectConfig</param-name>
    <param-value>resources.xml</param-value>
  </context-param>
</web-app>

The context param "simjectConfig" specifies the filename of the configuration.

That's all!