The Oracle Java data cartridge uses the cartridge ID com.oracle.cep.cartrdiges.java.

The Oracle Java data cartridge is the default Oracle Stream Analytics data cartridge.

For types under the default Java package name or types under the system package of java.lang, you can reference the Java type in an Oracle CQL query unqualified by package or data cartridge name:

<query id="q1"><![CDATA[
    select String(“foo") …
></query>

For more information, see: Class Loading.

The Oracle Java data cartridge supports the following policies for loading the Java classes that your Oracle CQL queries reference:

• Application Class Space Policy

• No Automatic Import Class Space Policy

• Server Class Space Policy

For more information, see:

• Class Loading Example

• Method Resolution

1. All parameter types are converted to Java types as Datatype Mapping describes.

   For example, an Oracle CQL INTEGER is converted to a Java primitive int.

2. Standard Java method resolution rules are applied as the Java Language Specification, Third Edition, Section 15.12, "Method Invocation Expressions" describes.

attribute.methodA(10)

You may use Oracle Java data cartridge types in expressions within a SELECT clause and WHERE clause.

You may not use Oracle Java data cartridge types in expressions within an ORDER BY clause.

For more information, see Using the Oracle Java Data Cartridge.

1. Implement the Address.java class.

   package test;
   
   class Address {
       String street;
       String state;
       String city;
       String [] phones;
   }
   

   In this example, assume that the Address.java class belongs to this application.

   If the Address.java class belonged to another Oracle Stream Explorer application, it must be exported in its parent application. For more information, see How to Query Using Exported Java Classes.

2. Define the event type repository.

   <event-type-repository>
       <event-type name="Student">
           <properties>
               <property name="name" type="char"/>
               <property name="address" type="Address"/>
           </properties>
       </event-type>
   
       <event-type name="Address">
           <class-name>test.Address</class-name>
       </event-type>
   <event-type-repository>
   

   Because the test.Address class belongs to this application, it can be declared in the event type repository. This automatically makes the class globally accessible within this application; its package does not need to be exported.

3. Assume that an adapter is providing Student events to channel StudentStream:

   <channel id="StudentStream" event-type="Student"/>
   

4. Assume that the StudentStream is connected to a processor with the Oracle CQL query q1.

   <processor> 
       <rules>

           <query id="q1"><![CDATA[ 

               select 
                   name, 
                   address.street as street, 
                   address.phones[0] as primary_phone 
               from 
                   StudentStream

           ></query>

       </rules>
   </processor>
   

   The Oracle Java data cartridge allows you to access the address event property from within the Oracle CQL query using normal Java API.

1. Implement the Address.java class.

   package test;
   
   class Address {
       String street;
       String state;
       String city;
       String [] phones;
   }
   

2. Export the test package that contains the Address.java class.

   For more information, see Oracle Fusion Middleware Developing Applications for Event Processing with Oracle Stream Analytics.

   The test package may be part of this Oracle Stream Analytics application or it may be part of some other Oracle Stream Analytics application deployed to the same Oracle Stream Analytics server as this application.

3. Define the event type repository.

   <event-type-repository>
       <event-type name="Student">
           <property name="name" type="char"/>
           <property name="address" type="Address"/>
       </event-type>
   <event-type-repository>
   

4. Assume that an adapter is providing Student events to channel StudentStream:

   <channel id="StudentStream" event-type="Student"/>
   

5. Assume that the StudentStream is connected to a processor with the Oracle CQL query q1.

   <processor> 
       <rules>

           <query id="q1"><![CDATA[ 

               select 
                   name, 
                   address.street as street, 
                   address.phones[0] as primary_phone 
               from 
                   StudentStream

           ></query>

       </rules>
   </processor>
   

   The Oracle Java data cartridge allows you to access the address event property from within the Oracle CQL query using normal Java API.

The Java cartridge provides the Java Cast function that enables a Java extensible type to be cast to another Java extensible type, providing the latter can be assigned from the former. To use this function, you must have the Java cartridge installed.

T cast@java(l-value, class-literal<T>)

public class Parent 
{
...
}
 
public class Child extends Parent
{
...
}

cast@java(S.parent, Child.class)