Field-Based Injection

To use field-based resource injection, declare a field and decorate it with the @Resource annotation. The container will infer the name and type of the resource if the name and type elements are not specified. If you do specify the type element, it must match the field’s type declaration.

package com.example;

public class SomeClass {
    @Resource
    private javax.sql.DataSource myDB;
...
}

In the code above, the container infers the name of the resource based on the class name and the field name: com.example.SomeClass/myDB. The inferred type is javax.sql.DataSource.class.

package com.example;

public class SomeClass {
    @Resource(name="customerDB")
    private javax.sql.DataSource myDB;
...
}

In the code above, the JNDI name is customerDB, and the inferred type is javax.sql.DataSource.class.