JavaGC打印日志设置

- Oracle JDK 1.8 (experimental support) -Xloggc: [-XX:+PrintGCDetails] [-XX:+PrintGCDateStamps]
- Sun / Oracle JDK 1.7 with option -Xloggc: [-XX:+PrintGCDetails] [-XX:+PrintGCDateStamps]
- Sun / Oracle JDK 1.6 with option -Xloggc: [-XX:+PrintGCDetails] [-XX:+PrintGCDateStamps]
- Sun JDK 1.4/1.5 with the option -Xloggc: [-XX:+PrintGCDetails]
- Sun JDK 1.2.2/1.3.1/1.4 with the option -verbose:gc
- IBM JDK 1.3.1/1.3.0/1.2.2 with the option -verbose:gc
- IBM iSeries Classic JVM 1.4.2 with option -verbose:gc
- HP-UX JDK 1.2/1.3/1.4.x with the option -Xverbosegc
- BEA JRockit 1.4.2/1.5/1.6 with the option -verbose:memory [-Xverbose:gcpause,gcreport] [-Xverbosetimestamp]