Java Platform, Enterprise Edition (Java EE) 8 The Java EE Tutorial

## Packaging CDI Applications

When you deploy a Java EE application, CDI looks for beans inside bean archives. A bean archive is any module that contains beans that the CDI runtime can manage and inject. There are two kinds of bean archives: explicit bean archives and implicit bean archives.

An explicit bean archive is an archive that contains a `beans.xml` deployment descriptor, which can be an empty file, contain no version number, or contain the version number 1.1 with the `bean-discovery-mode` attribute set to `all`. For example:

    <?xml version="1.0" encoding="UTF-8"?>
    <beans xmlns="http://xmlns.jcp.org/xml/ns/javaee"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee
                               http://xmlns.jcp.org/xml/ns/javaee/beans_1_1.xsd"
           version="1.1" bean-discovery-mode="all">
        ...
    </beans>

CDI can manage and inject any bean in an explicit archive, except those annotated with `@Vetoed`.

An implicit bean archive is an archive that contains some beans annotated with a scope type, contains no `beans.xml` deployment descriptor, or contains a `beans.xml` deployment descriptor with the `bean-discovery-mode` attribute set to `annotated`.

In an implicit archive, CDI can only manage and inject beans annotated with a scope type.

For a web application, the `beans.xml` deployment descriptor, if present, must be in the `WEB-INF` directory. For EJB modules or JAR files, the `beans.xml` deployment descriptor, if present, must be in the `META-INF` directory.

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