TIOBE - Java Coding Standard

Rule: StringandStringBuffer7

Synopsis:	Avoid appending characters as strings in StringBuffer.append
Language:	Java
Severity Level:	5
Category:	StringandStringBuffer

Description:

Avoid concatenating characters as strings in StringBuffer.append.

public class Foo {
 void bar() {
  StringBuffer sb=new StringBuffer();
  // Avoid this
  sb.append("a");

  // use instead something like this
  StringBuffer sb=new StringBuffer();
  sb.append('a');
 }
}