CDI
January 12, 2019
CDI

References

Predefined Beans

Predefined Bean Resource or CDI Bean Injection Example
UserTransaction Resource @Resource UserTransaction transaction;
Principal Resource @Resource Principal principal;
Validator Resource @Resource Validator validator;
ValidatorFactory Resource @Resource ValidatorFactory factory;
HttpServletRequest CDI bean @Inject HttpServletRequest req;
HttpSession CDI bean @Inject HttpSession session;
ServletContext CDI bean @Inject ServletContext context;

Predefined beans are injected with dependent scope and the predefined default qualifier @Default.

Resource Injection

Resource injection enables you to inject any resource available in the JNDI namespace into any container-managed object, such as a servlet, an enterprise bean, or a managed bean. For example, you can use resource injection to inject data sources, connectors, or custom resources available in the JNDI namespace.

For example, the following code injects a data source object that provides connections to the default Java DB database shipped with GlassFish Server:

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public class MyServlet extends HttpServlet {
    @Resource(name="java:comp/DefaultDataSource")
    private javax.sql.DataSource dsc;
    ...
}

JNDI Example 

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import jakarta.annotation.PostConstruct;
import jakarta.annotation.Resource;
import jakarta.enterprise.context.ApplicationScoped;

import java.util.HashMap;
import java.util.Map;
import java.util.Set;

@ApplicationScoped
public class JndiLLMConfig extends LLMConfig {

    @Resource(lookup = "java:global/llm.api.key")
    private String apiKey;

    @Resource(lookup = "java:global/llm.model")
    private String model;

    private Map<String, String> properties;

    @PostConstruct
    public void init() {
        properties = new HashMap<>();
        properties.put("llm.api.key", apiKey);
        properties.put("llm.model", model);
    }

    @Override
    public Set<String> getPropertyKeys() {
        return properties.keySet();
    }

    @Override
    public String getValue(String key) {
        return properties.get(key);
    }
}

Using asadmin CLI

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asadmin create-custom-resource \
--restype java.lang.String \
--factoryclass org.glassfish.resources.custom.factory.PrimitivesAndStringFactory \
--property value=YOUR_API_KEY \
java:global/llm.api.key

asadmin create-custom-resource \
--restype java.lang.String \
--factoryclass org.glassfish.resources.custom.factory.PrimitivesAndStringFactory \
--property value=gpt-4 \
java:global/llm.model

Using domain.xml

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<custom-resource 
    jndi-name="java:global/llm.api.key"
    res-type="java.lang.String"
    factory-class="org.glassfish.resources.custom.factory.PrimitivesAndStringFactory">
    <property name="value" value="YOUR_API_KEY"/>
</custom-resource>

<custom-resource 
    jndi-name="java:global/llm.model"
    res-type="java.lang.String"
    factory-class="org.glassfish.resources.custom.factory.PrimitivesAndStringFactory">
    <property name="value" value="gpt-4"/>
</custom-resource>

Then restart domain

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asadmin restart-domain