StringConcatenationInsideStringBufferAppend

Reports String concatenation used as the argument to StringBuffer.append(), StringBuilder.append() or Appendable.append().

Such calls may profitably be turned into chained append calls on the existing StringBuffer/Builder/Appendable saving the cost of an extra StringBuffer/Builder allocation. This inspection ignores compile-time evaluated String concatenations, in which case the conversion would only worsen performance.

Example:

void bar(StringBuilder builder, String name) {
    builder.append("Hello," + name); //warning
    builder.append("Hello," + "world"); //no warning
  }