Page Comparison

Online Resources For Java Coding Best Practices

• Java: Code Conventions for the Java Programming Language
  • http://java.sun.com/docs/codeconv/

• Java Practices
  • http://www.javapractices.com/index.cjp

• Writing Robust Java Code
  • http://www.ambysoft.com/downloads/javaCodingStandards.pdf#search=%22java%20%20coding%20standards%22

...

SAKAI

• Best Practices for High Quality Code

Common Java coding problems

• What is the best way to check

...

• if a Java String object is empty?

Solution 1:

someString.equals("");

• Pros:
  • readable
• Cons:
  • possible null pointer exception if someString is null
  • create extra String object (""). Overhead can be reduced by using static final String EMPTY_STRING = "";
  • not very efficient because equals first does a string length comparison

Solution 2:

public boolean isNotNullAndEmpty(String str) {

	if((null != str) && (str.length() == 0)) {
		return true;
	}
	else {
		return false;
	}
	
	// ... or just
	// return (str == null) ? false : str.length() == 0;
}

• Pros:
  • tests for null string
  • efficient
  • abstraction
• Cons:
  • a bit more code to write

Solution 3:

"".equals(someString);

• Pros:
  • avoids the null pointer exception issue that Solution 1 has
  • readable but awkward at first
• Cons:
  • create extra String object (""). Overhead can be reduced by using static final String EMPTY_STRING = "";
  • not very efficient because equals first does a string length comparison

Conclusion

...

Common Java Security Anti-patterns

Common Java Platform Antipatterns

1. Assuming objects are immutable
2. Basing security checks on untrusted sources
3. Ignoring changes to superclasses
4. Neglecting to validate inputs
5. Misusing public static variables
6. Believing a constructor exception destroys
   the object

This powerpoint presentation comes from the JavaOne 2006 presentation entitled 'Common Java Security Anti-patterns'. It contains code examples of each of the above antipatterns.