I wonder if these numbers have some variation per platform? For me (on Windows; 32-bit JDKs), the results of this test (java -verbose:class | grep Loaded | wc -l) are:
1.5.0_22: 239 1.6.0_21: 274 1.7.0-ea-b103: 403 The diff from 1.5 to 1.6 is not bad, but JDK7 seems right now to be a heavy regression... FWIW for such a simple test. For one thing, these core-boot classes all come off the CDS file so their classloading effort is relatively very small, and the delta will certainly be much smaller for even the smallest real-world app. A+ Osvaldo 2010/7/30 Mandy Chung <mandy.ch...@oracle.com>: > Yongqiang Yang wrote: >> >> hi, >> >> I just type command "java" under openjdk1.6, then the jvm will load >> 308 classes, including java/launcher/LauncherHelp, >> java/util/ResourceBundle, >> java/util/Currency, >> java/util/Locale, >> java/net/URL >> >> When I use jdk1.5, the jvm just load about 180 classes, not >> including the classes above. >> >> Could someone figure out something wrong? > > New features and bug fixes in a new release could lead to more classes get > loaded at startup. We have done some work to lazily load classes if > appropriate (see CR 6798873: Reduce the number of classes loaded and class > dependencies). > > Mandy > >
