据我所知，ClassLoader加载的类永远不会被卸载。
但是看看在Weblogic JVM内存不足之前输出的内容。
这是否意味着JVM试图在绝望的回收内存中试图卸载一堆类？ （可能是弱参考？）
- 索尼
111812.602: [Full GC[Unloading class sun.reflect.GeneratedConstructorAccessor1390]
[Unloading class sun.reflect.GeneratedMethodAccessor4153]
[Unloading class sun.reflect.GeneratedMethodAccessor4155]
[Unloading class sun.reflect.GeneratedMethodAccessor5253]
[Unloading class sun.reflect.GeneratedMethodAccessor5251]
[Unloading class sun.reflect.GeneratedMethodAccessor7012]
[Unloading class sun.reflect.GeneratedMethodAccessor5231]
[Unloading class sun.reflect.GeneratedMethodAccessor5252]
[Unloading class sun.reflect.GeneratedMethodAccessor4149]
[Unloading class sun.reflect.GeneratedMethodAccessor5270]
[Unloading class sun.reflect.GeneratedMethodAccessor5269]
[Unloading class sun.reflect.GeneratedMethodAccessor7011]
[Unloading class sun.reflect.GeneratedSerializationConstructorAccessor348]
[Unloading class sun.reflect.GeneratedMethodAccessor4152]
[Unloading class sun.reflect.GeneratedMethodAccessor7143]
[Unloading class sun.reflect.GeneratedConstructorAccessor1680]
[Unloading class sun.reflect.GeneratedConstructorAccessor1684]
[Unloading class sun.reflect.GeneratedMethodAccessor5650]
[Unloading class sun.reflect.GeneratedMethodAccessor5232]
[Unloading class sun.reflect.GeneratedMethodAccessor5254]
…
…
…
[Unloading class sun.reflect.GeneratedMethodAccessor4540]
[Unloading class sun.reflect.GeneratedMethodAccessor4537]
[Unloading class sun.reflect.GeneratedMethodAccessor4085]
[Unloading class sun.reflect.GeneratedMethodAccessor411]
[PSYoungGen: 466089K->0K(1201792K)] [ParOldGen: 3112457K->3186267K(3413376K)] 3578546K->3186267K(4615168K) [PSPermGen: 599209K->587324K(786432K)], 5.9899030 secs] [Times: user=21.70 sys=0.00, real=5.99 secs]
java.lang.OutOfMemoryError: Java heap space
[Loaded sun.reflect.GeneratedSerializationConstructorAccessor352 from __JVM_DefineClass__]
[Loaded sun.reflect.GeneratedSerializationConstructorAccessor353 from __JVM_DefineClass__]
Dumping heap to /opt/app/p1ibp3m2/appl/ordermanagement/log/java_pid24100.hprof ...
Heap dump file created [4016788478 bytes in 82.703 secs]
[Loaded sun.reflect.GeneratedSerializationConstructorAccessor354 from __JVM_DefineClass__]
***************************************************************************
The WebLogic Server encountered a critical failure
java.lang.OutOfMemoryError: Java heap space