Rule Definition
One of the fundamental OO performance management principles is this: Avoid excessive object creation. This doesn't mean that you should give up the benefits of object-oriented programming by not creating any objects, but you should be wary of object creation inside of tight loops when executing performance-critical code. Object creation is expensive enough that you should avoid unnecessarily creating temporary or intermediate objects in situations where performance is an issue.

Remediation
Redesign the loop.

Violation Code Sample

public class MyLoop {
     public void printCount() {
         for (int i = 0; i < 100; i++) {
             StringBuffer sb = new StringBuffer(); // VIOLATION
             sb.append("count = ");
             sb.append(i);
             System.out.println(sb);
         }
     }
 }

Fixed Code Sample

public class MyLoop {
     public void printCount() {
         StringBuffer sb = new StringBuffer(); // FIXED
         for (int i = 0; i < 100; i++) {
             sb.setLength(0);
             sb.append("count = ");
             sb.append(i);
             System.out.println(sb);
         }
     }
 }