EJB Bad Practices: Use of Java I/O
The program violates the Enterprise JavaBeans (EJB) specification by using the java.io package.
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 program violates the following EJB guideline: "An enterprise bean must not use the java.io package to attempt to access files and directories in the file system." The specification justifies this requirement in the following way: "The file system APIs are not well-suited for business components to access data. Business components should use a resource manager API, such as JDBC, to store data."
The following examples help to illustrate the nature of this weakness and describe methods or techniques which can be used to mitigate the risk.
Note that the examples here are by no means exhaustive and any given weakness may have many subtle varieties, each of which may require different detection methods or runtime controls.
The following Java example is a simple stateless Enterprise JavaBean that retrieves the interest rate for the number of points for a mortgage. In this example, the interest rates for various points are retrieved from an XML document on the local file system, and the EJB uses the Java I/O API to retrieve the XML document from the local file system.
This use of the Java I/O API within any kind of Enterprise JavaBean violates the EJB specification by using the java.io package for accessing files within the local filesystem.
An Enterprise JavaBean should use a resource manager API for storing and accessing data. In the following example, the private member function getInterestRateFromXMLParser uses an XML parser API to retrieve the interest rates.
This category identifies Software Fault Patterns (SFPs) within the Use of an Improper API cluster (SFP3).
This view (slice) covers all the elements in CWE.
This view (slice) lists weaknesses that can be introduced during implementation.
This view (slice) lists weaknesses that can be introduced during design.