High CPU due to heavy use of String.replaceAll

Issue

• We see high CPU usage on our JBoss server and CPU/thread dump data shows that the CPU is consumed by several threads in calls to String.replaceAll(), for example:

"ajp-127.0.0.1-8009-1" daemon prio=10 tid=0x00000000476fd000 nid=0xa73 runnable [0x000000004c1ab000]
   java.lang.Thread.State: RUNNABLE
    at java.util.regex.Pattern.atom(Pattern.java:1980)
    at java.util.regex.Pattern.sequence(Pattern.java:1885)
    at java.util.regex.Pattern.expr(Pattern.java:1752)
    at java.util.regex.Pattern.compile(Pattern.java:1460)
    at java.util.regex.Pattern. (Pattern.java:1133)
    at java.util.regex.Pattern.compile(Pattern.java:823)
    at java.lang.String.replaceAll(String.java:2189)
        ...

"ajp-10.133.72.102-8009-2" daemon prio=10 tid=0x0000000046406000 nid=0xa74 runnable [0x000000004c2ac000]
   java.lang.Thread.State: RUNNABLE
    at java.lang.String.length(String.java:651)
    at java.util.regex.Matcher.getTextLength(Matcher.java:1140)
    at java.util.regex.Matcher.reset(Matcher.java:291)
    at java.util.regex.Matcher. (Matcher.java:211)
    at java.util.regex.Pattern.matcher(Pattern.java:888)
    at java.lang.String.replaceAll(String.java:2189)
        ...