CWE-575 EJB不安全实践：使用AWT Swing

EJB Bad Practices: Use of AWT Swing

结构: Simple

Abstraction: Variant

状态: Draft

被利用可能性: unkown

基本描述

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

扩展描述

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 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."

相关缺陷

  • cwe_Nature: ChildOf cwe_CWE_ID: 695 cwe_View_ID: 1000 cwe_Ordinal: Primary

  • cwe_Nature: ChildOf cwe_CWE_ID: 695 cwe_View_ID: 699 cwe_Ordinal: Primary

适用平台

Language: {'cwe_Name': 'Java', 'cwe_Prevalence': 'Undetermined'}

常见的影响

范围 影响 注释
Other Quality Degradation

可能的缓解方案

Architecture and Design

策略:

Do not use AWT/Swing when writing EJBs.

示例代码

例

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.

bad Java

@Stateless
public class ConverterSessionBean extends Component implements KeyListener, ConverterSessionRemote {

/ member variables for receiving keyboard input using AWT API /

...
private StringBuffer enteredText = new StringBuffer();

/ conversion rate on US dollars to Yen /

private BigDecimal yenRate = new BigDecimal("115.3100");

public ConverterSessionBean() {
super();
/ method calls for setting up AWT Component for receiving keyboard input /

...
addKeyListener(this);
}

public BigDecimal dollarToYen(BigDecimal dollars) {
BigDecimal result = dollars.multiply(yenRate);
return result.setScale(2, BigDecimal.ROUND_DOWN);
}

/ member functions for implementing AWT KeyListener interface /

public void keyTyped(KeyEvent event) {
...
}

public void keyPressed(KeyEvent e) {
}

public void keyReleased(KeyEvent e) {
}

/ member functions for receiving keyboard input and displaying output /

public void paint(Graphics g) {...}

...
}

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.

good Java

@Stateless
public class ConverterSessionBean implements ConverterSessionRemoteInterface {

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

public ConverterSessionBean() {
}

/ remote method to convert US dollars to Yen /

public BigDecimal dollarToYen(BigDecimal dollars) {
BigDecimal result = dollars.multiply(yenRate);
return result.setScale(2, BigDecimal.ROUND_DOWN);
}
}

good JSP

<%@ page import="converter.ejb.Converter, java.math., javax.naming."%>
<%!
private Converter converter = null;
public void jspInit() {
try {
InitialContext ic = new InitialContext();
converter = (Converter) ic.lookup(Converter.class.getName());
} catch (Exception ex) {
System.out.println("Couldn't create converter bean."+ ex.getMessage());
}
}
public void jspDestroy() {
converter = null;
}

%>
<html>
<head><title>Converter</title></head>
<body bgcolor="white">
<h1>Converter</h1>
<hr>
<p>Enter an amount to convert:</p>
<form method="get">
<input type="text" name="amount" size="25"><br>
<p>
<input type="submit" value="Submit">
<input type="reset" value="Reset">
</form>
<%
String amount = request.getParameter("amount");
if ( amount != null && amount.length() > 0 ) {
BigDecimal d = new BigDecimal(amount);
BigDecimal yenAmount = converter.dollarToYen(d);

%>
<p>
<%= amount %> dollars are <%= yenAmount %> Yen.
<p>
<%
}

%>
</body>
</html>

分类映射

映射的分类名 ImNode ID Fit Mapped Node Name
Software Fault Patterns SFP3 Use of an improper API