EJB Bad Practices: Use of AWT Swing

Draft Variant

Structure: Simple

Description

The product violates the Enterprise JavaBeans (EJB) specification by using AWT/Swing.

Extended Description

The Enterprise JavaBeans specification requires that every bean provider follow a set of programming guidelines designed to ensure that the bean will be portable and behave consistently in any EJB container. In this case, the product violates the following EJB guideline: "An enterprise bean must not use the AWT functionality to attempt to output information to a display, or to input information from a keyboard." The specification justifies this requirement in the following way: "Most servers do not allow direct interaction between an application program and a keyboard/display attached to the server system."

Common Consequences 1

Scope: Other

Impact: Quality Degradation

Potential Mitigations 1

Phase: Architecture and Design

Do not use AWT/Swing when writing EJBs.

Demonstrative Examples 1

The following Java example is a simple converter class for converting US dollars to Yen. This converter class demonstrates the improper practice of using a stateless session Enterprise JavaBean that implements an AWT Component and AWT keyboard event listener to retrieve keyboard input from the user for the amount of the US dollars to convert to Yen.

Code Example:

Bad

Java

java

/* member variables for receiving keyboard input using AWT API /

java

java

/* member functions for implementing AWT KeyListener interface /

java

java

This use of the AWT and Swing APIs within any kind of Enterprise JavaBean not only violates the restriction of the EJB specification against using AWT or Swing within an EJB but also violates the intended use of Enterprise JavaBeans to separate business logic from presentation logic.

The Stateless Session Enterprise JavaBean should contain only business logic. Presentation logic should be provided by some other mechanism such as Servlets or Java Server Pages (JSP) as in the following Java/JSP example.

Code Example:

Good

Java

java

/* conversion rate on US dollars to Yen / private BigDecimal yenRate = new BigDecimal("115.3100");

java

Code Example:Good
JSP
jsp

Applicable Platforms

Languages:

Java : Undetermined

Modes of Introduction

Implementation

Related Weaknesses

ChildOf:

Use of Low-Level Functionality (CWE-695)

Taxonomy Mapping

Software Fault Patterns