High CPU due to StringBuilder.append calls

Issue

• High CPU due to StringBuilder.append calls
• Taking thread dumps and CPU data shows that calls are taking a long time in the following stack:

"ajp-/IP:PORT-THREAD_NUM" daemon prio=10 tid=0x0000000002353000 nid=0x24d9 runnable [0x0000000044550000]
   java.lang.Thread.State: RUNNABLE
    at java.util.Arrays.copyOf(Arrays.java:2367)
    at java.lang.AbstractStringBuilder.expandCapacity(AbstractStringBuilder.java:130)
    at java.lang.AbstractStringBuilder.ensureCapacityInternal(AbstractStringBuilder.java:114)
    at java.lang.AbstractStringBuilder.append(AbstractStringBuilder.java:415)
    at java.lang.StringBuilder.append(StringBuilder.java:132)
    at some.package.thirdPartyClass.usingStringBuilder(thirdPartyClass.java:10)