java -verbose:class可以查看JVM加载类的细节情况:

C:\Documents and Settings\bobstone>java -verbose:class
[Opened C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Opened C:\JBuilderX\jdk1.4\jre\lib\sunrsasign.jar]
[Opened C:\JBuilderX\jdk1.4\jre\lib\jsse.jar]
[Opened C:\JBuilderX\jdk1.4\jre\lib\jce.jar]
[Opened C:\JBuilderX\jdk1.4\jre\lib\charsets.jar]
[Loaded java.lang.Object from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.io.Serializable from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.Comparable from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.CharSequence from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.String from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.Class from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.Cloneable from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.ClassLoader from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.System from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.Throwable from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.Error from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.ThreadDeath from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.Exception from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.RuntimeException from C:\JBuilderX\jdk1.4\jre\lib\rt.ja
[Loaded java.security.ProtectionDomain from C:\JBuilderX\jdk1.4\jre\lib\r
[Loaded java.security.AccessControlContext from C:\JBuilderX\jdk1.4\jre\l
ar]
[Loaded java.lang.ClassNotFoundException from C:\JBuilderX\jdk1.4\jre\lib
]
[Loaded java.lang.LinkageError from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.NoClassDefFoundError from C:\JBuilderX\jdk1.4\jre\lib\r
[Loaded java.lang.ClassCastException from C:\JBuilderX\jdk1.4\jre\lib\rt.
[Loaded java.lang.ArrayStoreException from C:\JBuilderX\jdk1.4\jre\lib\rt
[Loaded java.lang.VirtualMachineError from C:\JBuilderX\jdk1.4\jre\lib\rt
[Loaded java.lang.OutOfMemoryError from C:\JBuilderX\jdk1.4\jre\lib\rt.ja
[Loaded java.lang.StackOverflowError from C:\JBuilderX\jdk1.4\jre\lib\rt.
[Loaded java.lang.ref.Reference from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.ref.SoftReference from C:\JBuilderX\jdk1.4\jre\lib\rt.j
[Loaded java.lang.ref.WeakReference from C:\JBuilderX\jdk1.4\jre\lib\rt.j
[Loaded java.lang.ref.FinalReference from C:\JBuilderX\jdk1.4\jre\lib\rt.
[Loaded java.lang.ref.PhantomReference from C:\JBuilderX\jdk1.4\jre\lib\r
[Loaded java.lang.ref.Finalizer from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.Runnable from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.Thread from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.ThreadGroup from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.util.Dictionary from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.util.Map from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.util.Hashtable from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.util.Properties from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.reflect.AccessibleObject from C:\JBuilderX\jdk1.4\jre\l
ar]
[Loaded java.lang.reflect.Member from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.reflect.Field from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.reflect.Method from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.reflect.Constructor from C:\JBuilderX\jdk1.4\jre\lib\rt
[Loaded sun.reflect.MagicAccessorImpl from C:\JBuilderX\jdk1.4\jre\lib\rt
[Loaded sun.reflect.MethodAccessor from C:\JBuilderX\jdk1.4\jre\lib\rt.ja
[Loaded sun.reflect.MethodAccessorImpl from C:\JBuilderX\jdk1.4\jre\lib\r
[Loaded sun.reflect.ConstructorAccessor from C:\JBuilderX\jdk1.4\jre\lib\

[Loaded sun.reflect.ConstructorAccessorImpl from C:\JBuilderX\jdk1.4\jre\
jar]
[Loaded sun.reflect.DelegatingClassLoader from C:\JBuilderX\jdk1.4\jre\li
r]
[Loaded java.util.Collection from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.util.AbstractCollection from C:\JBuilderX\jdk1.4\jre\lib\rt.
[Loaded java.util.List from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.util.AbstractList from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.util.RandomAccess from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.util.Vector from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.StringBuffer from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.nio.Buffer from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded sun.misc.AtomicLong from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded sun.misc.AtomicLongCSImpl from C:\JBuilderX\jdk1.4\jre\lib\rt.jar
[Loaded java.lang.Boolean from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.Character from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.Number from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.Float from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.Double from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.Byte from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.Short from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.Integer from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.Long from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.NullPointerException from C:\JBuilderX\jdk1.4\jre\lib\r
[Loaded java.lang.ArithmeticException from C:\JBuilderX\jdk1.4\jre\lib\rt
[Loaded java.lang.StrictMath from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.io.ObjectStreamField from C:\JBuilderX\jdk1.4\jre\lib\rt.jar
[Loaded java.util.Comparator from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.String$CaseInsensitiveComparator from C:\JBuilderX\jdk1
lib\rt.jar]
[Loaded java.security.AccessController from C:\JBuilderX\jdk1.4\jre\lib\r
[Loaded java.security.Guard from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.security.Permission from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.security.BasicPermission from C:\JBuilderX\jdk1.4\jre\lib\rt
[Loaded java.lang.reflect.ReflectPermission from C:\JBuilderX\jdk1.4\jre\
jar]
[Loaded java.security.PrivilegedAction from C:\JBuilderX\jdk1.4\jre\lib\r
[Loaded sun.reflect.ReflectionFactory$GetReflectionFactoryAction from C:\
rX\jdk1.4\jre\lib\rt.jar]
[Loaded java.util.Stack from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded sun.reflect.ReflectionFactory from C:\JBuilderX\jdk1.4\jre\lib\rt
[Loaded java.lang.RuntimePermission from C:\JBuilderX\jdk1.4\jre\lib\rt.j
[Loaded java.lang.ref.Reference$Lock from C:\JBuilderX\jdk1.4\jre\lib\rt.
[Loaded java.lang.ref.Reference$ReferenceHandler from C:\JBuilderX\jdk1.4
b\rt.jar]
[Loaded java.lang.ref.ReferenceQueue from C:\JBuilderX\jdk1.4\jre\lib\rt.
[Loaded java.lang.ref.ReferenceQueue$Null from C:\JBuilderX\jdk1.4\jre\li
r]
[Loaded java.lang.ref.ReferenceQueue$Lock from C:\JBuilderX\jdk1.4\jre\li
r]
[Loaded java.lang.ref.Finalizer$FinalizerThread from C:\JBuilderX\jdk1.4\
\rt.jar]
[Loaded java.util.Enumeration from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.util.Hashtable$EmptyEnumerator from C:\JBuilderX\jdk1.4\jre\
jar]
[Loaded java.util.Iterator from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.util.Hashtable$EmptyIterator from C:\JBuilderX\jdk1.4\jre\li
r]
[Loaded java.io.ObjectStreamClass from C:\JBuilderX\jdk1.4\jre\lib\rt.jar
[Loaded java.util.AbstractMap from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded sun.misc.SoftCache from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.util.HashMap from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.util.Map$Entry from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.util.HashMap$Entry from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.IncompatibleClassChangeError from C:\JBuilderX\jdk1.4\j
rt.jar]
[Loaded java.lang.NoSuchMethodError from C:\JBuilderX\jdk1.4\jre\lib\rt.j
[Loaded java.util.Hashtable$Entry from C:\JBuilderX\jdk1.4\jre\lib\rt.jar
[Loaded java.lang.StringCoding from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.ThreadLocal from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded sun.io.Converters from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded sun.reflect.Reflection from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded sun.security.action.GetPropertyAction from C:\JBuilderX\jdk1.4\jr
t.jar]
[Loaded java.lang.ThreadLocal$ThreadLocalMap from C:\JBuilderX\jdk1.4\jre
.jar]
[Loaded java.lang.ThreadLocal$ThreadLocalMap$Entry from C:\JBuilderX\jdk1
lib\rt.jar]
[Loaded java.lang.CharacterDataLatin1 from C:\JBuilderX\jdk1.4\jre\lib\rt
[Loaded java.nio.charset.Charset from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.nio.charset.spi.CharsetProvider from C:\JBuilderX\jdk1.4\jre
.jar]
[Loaded sun.nio.cs.AbstractCharsetProvider from C:\JBuilderX\jdk1.4\jre\l
ar]
[Loaded sun.nio.cs.StandardCharsets from C:\JBuilderX\jdk1.4\jre\lib\rt.j
[Loaded java.util.SortedMap from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.util.TreeMap from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded sun.misc.ASCIICaseInsensitiveComparator from C:\JBuilderX\jdk1.4\
\rt.jar]
[Loaded java.util.TreeMap$Entry from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded sun.misc.VM from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.StringCoding$StringDecoder from C:\JBuilderX\jdk1.4\jre
.jar]
[Loaded java.lang.StringCoding$ConverterSD from C:\JBuilderX\jdk1.4\jre\l
ar]
[Loaded sun.io.ByteToCharConverter from C:\JBuilderX\jdk1.4\jre\lib\rt.ja
[Loaded sun.io.CharacterEncoding from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.util.Locale from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded sun.io.ByteToCharDoubleByte from C:\JBuilderX\jdk1.4\jre\lib\char
r]
[Loaded sun.io.ByteToCharGBK from C:\JBuilderX\jdk1.4\jre\lib\charsets.ja
[Loaded java.lang.Class$3 from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.reflect.Modifier from C:\JBuilderX\jdk1.4\jre\lib\rt.ja
[Loaded sun.reflect.LangReflectAccess from C:\JBuilderX\jdk1.4\jre\lib\rt
[Loaded java.lang.reflect.ReflectAccess from C:\JBuilderX\jdk1.4\jre\lib\

[Loaded java.lang.Class$1 from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded sun.reflect.ReflectionFactory$1 from C:\JBuilderX\jdk1.4\jre\lib\

[Loaded sun.reflect.NativeConstructorAccessorImpl from C:\JBuilderX\jdk1.
ib\rt.jar]
[Loaded sun.reflect.DelegatingConstructorAccessorImpl from C:\JBuilderX\j
re\lib\rt.jar]
[Loaded sun.misc.Version from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.io.InputStream from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.io.FileInputStream from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.io.FileDescriptor from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.io.OutputStream from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.io.FileOutputStream from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.io.FilterInputStream from C:\JBuilderX\jdk1.4\jre\lib\rt.jar
[Loaded java.io.BufferedInputStream from C:\JBuilderX\jdk1.4\jre\lib\rt.j
[Loaded java.io.FilterOutputStream from C:\JBuilderX\jdk1.4\jre\lib\rt.ja
[Loaded java.io.PrintStream from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.io.BufferedOutputStream from C:\JBuilderX\jdk1.4\jre\lib\rt.
[Loaded java.io.Writer from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.io.OutputStreamWriter from C:\JBuilderX\jdk1.4\jre\lib\rt.ja
[Loaded sun.nio.cs.StreamEncoder from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded sun.nio.cs.StreamEncoder$ConverterSE from C:\JBuilderX\jdk1.4\jre
.jar]
[Loaded sun.io.CharToByteConverter from C:\JBuilderX\jdk1.4\jre\lib\rt.ja
[Loaded sun.io.CharToByteDoubleByte from C:\JBuilderX\jdk1.4\jre\lib\char
r]
[Loaded sun.io.CharToByteGBK from C:\JBuilderX\jdk1.4\jre\lib\charsets.ja
[Loaded java.io.BufferedWriter from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.Runtime from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.io.File from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.io.FileSystem from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.io.Win32FileSystem from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.io.WinNTFileSystem from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.io.ExpiringCache from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.ClassLoader$3 from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.io.ExpiringCache$Entry from C:\JBuilderX\jdk1.4\jre\lib\rt.j
[Loaded java.lang.ClassLoader$NativeLibrary from C:\JBuilderX\jdk1.4\jre\
jar]
[Loaded java.lang.StringCoding$StringEncoder from C:\JBuilderX\jdk1.4\jre
.jar]
[Loaded java.lang.StringCoding$ConverterSE from C:\JBuilderX\jdk1.4\jre\l
ar]
[Loaded java.lang.Terminator from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded sun.misc.SignalHandler from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.Terminator$1 from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded sun.misc.Signal from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded sun.misc.NativeSignalHandler from C:\JBuilderX\jdk1.4\jre\lib\rt.
[Loaded java.lang.Integer$1 from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.Long$1 from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.Compiler from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.Compiler$1 from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded sun.misc.Launcher from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.net.URLStreamHandlerFactory from C:\JBuilderX\jdk1.4\jre\lib
]
[Loaded sun.misc.Launcher$Factory from C:\JBuilderX\jdk1.4\jre\lib\rt.jar
[Loaded java.security.SecureClassLoader from C:\JBuilderX\jdk1.4\jre\lib\

[Loaded java.net.URLClassLoader from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded sun.misc.Launcher$ExtClassLoader from C:\JBuilderX\jdk1.4\jre\lib
]
[Loaded sun.security.util.Debug from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.util.StringTokenizer from C:\JBuilderX\jdk1.4\jre\lib\rt.jar
[Loaded java.security.PrivilegedExceptionAction from C:\JBuilderX\jdk1.4\
\rt.jar]
[Loaded sun.misc.Launcher$1 from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded sun.net.www.ParseUtil from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.util.BitSet from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.net.URL from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.net.Parts from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.net.URLStreamHandler from C:\JBuilderX\jdk1.4\jre\lib\rt.jar
[Loaded sun.net.www.protocol.file.Handler from C:\JBuilderX\jdk1.4\jre\li
r]
[Loaded java.util.Set from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.util.AbstractSet from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.util.HashSet from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded sun.misc.URLClassPath from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.util.ArrayList from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded sun.net.www.protocol.jar.Handler from C:\JBuilderX\jdk1.4\jre\lib
]
[Loaded sun.misc.Launcher$AppClassLoader from C:\JBuilderX\jdk1.4\jre\lib
]
[Loaded sun.misc.Launcher$2 from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.SystemClassLoaderAction from C:\JBuilderX\jdk1.4\jre\li
r]
Usage: java [-options] class [args...]
           (to execute a class)
   or  java [-options] -jar jarfile [args...]
           (to execute a jar file)

where options include:
    -client       to select the "client" VM
    -server       to select the "server" VM
    -hotspot      is a synonym for the "client" VM  [deprecated]
                  The default VM is client.

    -cp <class search path of directories and zip/jar files>
    -classpath <class search path of directories and zip/jar files>
                  A ; separated list of directories, JAR archives,
                  and ZIP archives to search for class files.
    -D<name>=<value>
                  set a system property
    -verbose[:class|gc|jni]
                  enable verbose output
    -version      print product version and exit
    -showversion  print product version and continue
    -? -help      print this help message
    -X            print help on non-standard options
    -ea[:<packagename>...|:<classname>]
    -enableassertions[:<packagename>...|:<classname>]
                  enable assertions
    -da[:<packagename>...|:<classname>]
    -disableassertions[:<packagename>...|:<classname>]
                  disable assertions
    -esa | -enablesystemassertions
                  enable system assertions
    -dsa | -disablesystemassertions
                  disable system assertions
[Loaded java.lang.Shutdown from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]
[Loaded java.lang.Shutdown$Lock from C:\JBuilderX\jdk1.4\jre\lib\rt.jar]