在编译java程序和运行java程序时，为了更好的看到java程序对包的导入和对代码的解析操作 可以加入一点命令 轻松的观察！！！！
下面从最简单的Helloworld程序入手看看情况如何：
public class HelloWorld
{
public static void main(String []args)
{
Print print=new Print("hello world");
System.out.println(print);
}
}
class Print
{
private String str;
public Print(String str1)
{
str=str1;
}
public String toString()
{
return str;
}
}
下面再编译时用加入-verbose 即：javac -verbose HelloWorld.java 看控制台输出情况：
然后用 java -verbose 运行； 输出：
[Loaded java.lang.Comparable from shared objects file]
[Loaded java.lang.CharSequence from shared objects file]
[Loaded java.lang.String from shared objects file]
[Loaded java.lang.reflect.GenericDeclaration from shared objects file]
[Loaded java.lang.reflect.Type from shared objects file]
[Loaded java.lang.reflect.AnnotatedElement from shared objects file]
[Loaded java.lang.Class from shared objects file]
[Loaded java.lang.Cloneable from shared objects file]
[Loaded java.lang.ClassLoader from shared objects file]
[Loaded java.lang.System from shared objects file]
[Loaded java.lang.Throwable from shared objects file]
[Loaded java.lang.Error from shared objects file]
[Loaded java.lang.ThreadDeath from shared objects file]
[Loaded java.lang.Exception from shared objects file]
[Loaded java.lang.RuntimeException from shared objects file]
[Loaded java.security.ProtectionDomain from shared objects file]
[Loaded java.security.AccessControlContext from shared objects file]
[Loaded java.lang.ClassNotFoundException from shared objects file]
[Loaded java.lang.LinkageError from shared objects file]
[Loaded java.lang.NoClassDefFoundError from shared objects file]
[Loaded java.lang.ClassCastException from shared objects file]
[Loaded java.lang.ArrayStoreException from shared objects file]
[Loaded java.lang.VirtualMachineError from shared objects file]
[Loaded java.lang.OutOfMemoryError from shared objects file]
[Loaded java.lang.StackOverflowError from shared objects file]
[Loaded java.lang.ref.Reference from shared objects file]
[Loaded java.lang.ref.SoftReference from shared objects file]
[Loaded java.lang.ref.WeakReference from shared objects file]
[Loaded java.lang.ref.FinalReference from shared objects file]
[Loaded java.lang.ref.PhantomReference from shared objects file]
[Loaded java.lang.ref.Finalizer from shared objects file]
[Loaded java.lang.Runnable from shared objects file]
[Loaded java.lang.Thread from shared objects file]
[Loaded java.lang.Thread$UncaughtExceptionHandler from shared objects fi
[Loaded java.lang.ThreadGroup from shared objects file]
[Loaded java.util.Dictionary from shared objects file]
[Loaded java.util.Map from shared objects file]
[Loaded java.util.Hashtable from shared objects file]
[Loaded java.util.Properties from shared objects file]
[Loaded java.lang.reflect.AccessibleObject from shared objects file]
[Loaded java.lang.reflect.Member from shared objects file]
[Loaded java.lang.reflect.Field from shared objects file]
[Loaded java.lang.reflect.Method from shared objects file]
[Loaded java.lang.reflect.Constructor from shared objects file]
[Loaded sun.reflect.MagicAccessorImpl from shared objects file]
[Loaded sun.reflect.MethodAccessor from shared objects file]
[Loaded sun.reflect.MethodAccessorImpl from shared objects file]
[Loaded sun.reflect.ConstructorAccessor from shared objects file]
[Loaded sun.reflect.ConstructorAccessorImpl from shared objects file]
[Loaded sun.reflect.DelegatingClassLoader from shared objects file]
[Loaded sun.reflect.ConstantPool from shared objects file]
[Loaded java.lang.Iterable from shared objects file]
[Loaded java.util.Collection from shared objects file]
[Loaded java.util.AbstractCollection from shared objects file]
[Loaded java.util.List from shared objects file]
[Loaded java.util.AbstractList from shared objects file]
[Loaded java.util.RandomAccess from shared objects file]
[Loaded java.util.Vector from shared objects file]
[Loaded java.lang.Appendable from shared objects file]
[Loaded java.lang.AbstractStringBuilder from shared objects file]
[Loaded java.lang.StringBuffer from shared objects file]
[Loaded java.lang.StackTraceElement from shared objects file]
[Loaded java.nio.Buffer from shared objects file]
[Loaded sun.misc.AtomicLong from shared objects file]
[Loaded sun.misc.AtomicLongCSImpl from shared objects file]
[Loaded java.lang.Boolean from shared objects file]
[Loaded java.lang.Character from shared objects file]
[Loaded java.lang.Number from shared objects file]
[Loaded java.lang.Float from shared objects file]
[Loaded java.lang.Double from shared objects file]
[Loaded java.lang.Byte from shared objects file]
[Loaded java.lang.Short from shared objects file]
[Loaded java.lang.Integer from shared objects file]
[Loaded java.lang.Long from shared objects file]
[Loaded java.lang.management.MemoryUsage from shared objects file]
[Loaded java.lang.StrictMath from shared objects file]
[Loaded java.io.ObjectStreamField from shared objects file]
[Loaded java.util.Comparator from shared objects file]
[Loaded java.lang.String$CaseInsensitiveComparator from shared objects f
[Loaded java.security.Guard from shared objects file]
[Loaded java.security.Permission from shared objects file]
[Loaded java.security.BasicPermission from shared objects file]
[Loaded java.lang.RuntimePermission from shared objects file]
[Loaded java.util.AbstractMap from shared objects file]
[Loaded sun.misc.SoftCache from shared objects file]
[Loaded java.lang.ref.ReferenceQueue from shared objects file]
[Loaded java.lang.ref.ReferenceQueue$Null from shared objects file]
[Loaded java.lang.ref.ReferenceQueue$Lock from shared objects file]
[Loaded java.util.HashMap from shared objects file]
[Loaded java.io.ObjectStreamClass from shared objects file]
[Loaded java.security.PrivilegedAction from shared objects file]
[Loaded sun.reflect.ReflectionFactory$GetReflectionFactoryAction from sh
ects file]
[Loaded java.security.AccessController from shared objects file]
[Loaded java.util.Stack from shared objects file]
[Loaded sun.reflect.ReflectionFactory from shared objects file]
[Loaded java.util.Map$Entry from shared objects file]
[Loaded java.util.HashMap$Entry from shared objects file]
[Loaded java.lang.IncompatibleClassChangeError from shared objects file]
[Loaded java.lang.NoSuchMethodError from shared objects file]
[Loaded java.lang.annotation.Annotation from shared objects file]
[Loaded java.lang.reflect.ReflectPermission from shared objects file]
[Loaded java.lang.ref.Reference$Lock from shared objects file]
[Loaded java.lang.ref.Reference$ReferenceHandler from shared objects fil
[Loaded java.lang.ref.Finalizer$FinalizerThread from shared objects file
[Loaded java.util.Enumeration from shared objects file]
[Loaded java.util.Hashtable$EmptyEnumerator from shared objects file]
[Loaded java.util.Iterator from shared objects file]
[Loaded java.util.Hashtable$EmptyIterator from shared objects file]
[Loaded java.util.Hashtable$Entry from shared objects file]
[Loaded java.nio.charset.Charset from shared objects file]
[Loaded java.nio.charset.spi.CharsetProvider from shared objects file]
[Loaded sun.nio.cs.FastCharsetProvider from shared objects file]
[Loaded sun.nio.cs.StandardCharsets from shared objects file]
[Loaded sun.util.PreHashedMap from shared objects file]
[Loaded sun.nio.cs.StandardCharsets$Aliases from shared objects file]
[Loaded sun.nio.cs.StandardCharsets$Classes from shared objects file]
[Loaded sun.nio.cs.StandardCharsets$Cache from shared objects file]
[Loaded java.lang.ThreadLocal from shared objects file]
[Loaded java.nio.charset.Charset$3 from C:/Program Files/Java/jre1.5.0/l
r]
[Loaded sun.reflect.Reflection from shared objects file]
[Loaded java.util.Collections from shared objects file]
[Loaded java.util.Random from shared objects file]
[Loaded java.util.concurrent.atomic.AtomicLong from shared objects file]
[Loaded sun.misc.Unsafe from shared objects file]
[Loaded java.lang.Class$3 from shared objects file]
[Loaded java.lang.reflect.Modifier from shared objects file]
[Loaded sun.reflect.LangReflectAccess from shared objects file]
[Loaded java.lang.reflect.ReflectAccess from shared objects file]
[Loaded java.util.Set from shared objects file]
[Loaded java.util.AbstractSet from shared objects file]
[Loaded java.util.Collections$EmptySet from shared objects file]
[Loaded java.util.Collections$EmptyList from shared objects file]
[Loaded java.util.Collections$EmptyMap from shared objects file]
[Loaded java.util.Collections$ReverseComparator from shared objects file
[Loaded java.util.Collections$SynchronizedMap from shared objects file]
[Loaded sun.nio.cs.AbstractCharsetProvider from C:/Program Files/Java/jr
ib/rt.jar]
[Loaded sun.nio.cs.ext.ExtendedCharsets from C:/Program Files/Java/jre1.
charsets.jar]
[Loaded java.lang.Class$1 from shared objects file]
[Loaded sun.reflect.ReflectionFactory$1 from shared objects file]
[Loaded sun.reflect.NativeConstructorAccessorImpl from shared objects fi
[Loaded sun.reflect.DelegatingConstructorAccessorImpl from shared object
[Loaded java.util.SortedMap from shared objects file]
[Loaded java.util.TreeMap from shared objects file]
[Loaded sun.misc.ASCIICaseInsensitiveComparator from shared objects file
[Loaded java.util.TreeMap$Entry from shared objects file]
[Loaded sun.misc.VM from shared objects file]
[Loaded java.lang.StringBuilder from shared objects file]
[Loaded sun.nio.cs.ext.GBK from C:/Program Files/Java/jre1.5.0/lib/chars
[Loaded java.lang.StringCoding from shared objects file]
[Loaded java.lang.ThreadLocal$ThreadLocalMap from shared objects file]
[Loaded java.lang.ThreadLocal$ThreadLocalMap$Entry from shared objects f
[Loaded java.lang.StringCoding$StringDecoder from shared objects file]
[Loaded java.lang.StringCoding$CharsetSD from shared objects file]
[Loaded java.nio.charset.CharsetDecoder from shared objects file]
[Loaded sun.nio.cs.ext.DoubleByteDecoder from C:/Program Files/Java/jre1
/charsets.jar]
[Loaded sun.nio.cs.ext.GBK$Decoder from C:/Program Files/Java/jre1.5.0/l
ets.jar]
[Loaded java.nio.charset.CodingErrorAction from shared objects file]
[Loaded java.nio.ByteBuffer from shared objects file]
[Loaded java.nio.HeapByteBuffer from shared objects file]
[Loaded java.nio.Bits from shared objects file]
[Loaded java.nio.ByteOrder from shared objects file]
[Loaded java.lang.Readable from shared objects file]
[Loaded java.nio.CharBuffer from shared objects file]
[Loaded java.nio.HeapCharBuffer from shared objects file]
[Loaded java.nio.charset.CoderResult from shared objects file]
[Loaded java.nio.charset.CoderResult$Cache from shared objects file]
[Loaded java.nio.charset.CoderResult$1 from shared objects file]
[Loaded java.nio.charset.CoderResult$2 from shared objects file]
[Loaded sun.misc.Version from shared objects file]
[Loaded java.io.Closeable from shared objects file]
[Loaded java.io.InputStream from shared objects file]
[Loaded java.io.FileInputStream from shared objects file]
[Loaded java.io.FileDescriptor from shared objects file]
[Loaded java.io.Flushable from shared objects file]
[Loaded java.io.OutputStream from shared objects file]
[Loaded java.io.FileOutputStream from shared objects file]
[Loaded java.io.FilterInputStream from shared objects file]
[Loaded java.io.BufferedInputStream from shared objects file]
[Loaded java.util.concurrent.atomic.AtomicReferenceFieldUpdater from sha
cts file]
[Loaded java.util.concurrent.atomic.AtomicReferenceFieldUpdater$AtomicRe
ieldUpdaterImpl from shared objects file]
[Loaded java.io.FilterOutputStream from shared objects file]
[Loaded java.io.PrintStream from shared objects file]
[Loaded java.io.BufferedOutputStream from shared objects file]
[Loaded java.io.Writer from shared objects file]
[Loaded java.io.OutputStreamWriter from shared objects file]
[Loaded sun.nio.cs.StreamEncoder from shared objects file]
[Loaded sun.io.Converters from shared objects file]
[Loaded sun.security.action.GetPropertyAction from shared objects file]
[Loaded sun.nio.cs.StreamEncoder$CharsetSE from shared objects file]
[Loaded java.nio.charset.CharsetEncoder from shared objects file]
[Loaded sun.nio.cs.ext.DoubleByteEncoder from C:/Program Files/Java/jre1
/charsets.jar]
[Loaded sun.nio.cs.ext.GBK$Encoder from C:/Program Files/Java/jre1.5.0/l
ets.jar]
[Loaded sun.nio.cs.Surrogate$Parser from shared objects file]
[Loaded sun.nio.cs.Surrogate from shared objects file]
[Loaded java.io.BufferedWriter from shared objects file]
[Loaded java.lang.Runtime from shared objects file]
[Loaded java.io.File from shared objects file]
[Loaded java.io.FileSystem from shared objects file]
[Loaded java.io.Win32FileSystem from shared objects file]
[Loaded java.io.WinNTFileSystem from shared objects file]
[Loaded java.io.ExpiringCache from shared objects file]
[Loaded java.util.LinkedHashMap from shared objects file]
[Loaded java.io.ExpiringCache$1 from shared objects file]
[Loaded java.util.LinkedHashMap$Entry from shared objects file]
[Loaded java.lang.ClassLoader$3 from shared objects file]
[Loaded java.io.ExpiringCache$Entry from shared objects file]
[Loaded java.lang.ClassLoader$NativeLibrary from shared objects file]
[Loaded java.lang.StringCoding$StringEncoder from shared objects file]
[Loaded java.lang.StringCoding$CharsetSE from shared objects file]
[Loaded java.lang.Terminator from shared objects file]
[Loaded sun.misc.SignalHandler from shared objects file]
[Loaded java.lang.Terminator$1 from shared objects file]
[Loaded sun.misc.Signal from shared objects file]
[Loaded sun.misc.NativeSignalHandler from shared objects file]
[Loaded sun.misc.JavaLangAccess from shared objects file]
[Loaded java.lang.System$2 from shared objects file]
[Loaded sun.misc.SharedSecrets from shared objects file]
[Loaded java.lang.NullPointerException from shared objects file]
[Loaded java.lang.ArithmeticException from shared objects file]
[Loaded java.lang.Compiler from shared objects file]
[Loaded java.lang.Compiler$1 from shared objects file]
[Loaded sun.misc.Launcher from shared objects file]
[Loaded java.net.URLStreamHandlerFactory from shared objects file]
[Loaded sun.misc.Launcher$Factory from shared objects file]
[Loaded java.security.SecureClassLoader from shared objects file]
[Loaded java.net.URLClassLoader from shared objects file]
[Loaded sun.misc.Launcher$ExtClassLoader from shared objects file]
[Loaded sun.security.util.Debug from shared objects file]
[Loaded java.util.StringTokenizer from shared objects file]
[Loaded java.security.PrivilegedExceptionAction from shared objects file
[Loaded sun.misc.Launcher$ExtClassLoader$1 from shared objects file]
[Loaded sun.net.www.ParseUtil from shared objects file]
[Loaded java.util.BitSet from shared objects file]
[Loaded java.net.URL from shared objects file]
[Loaded java.util.Locale from shared objects file]
[Loaded java.lang.CharacterDataLatin1 from shared objects file]
[Loaded java.net.Parts from shared objects file]
[Loaded java.net.URLStreamHandler from shared objects file]
[Loaded sun.net.www.protocol.file.Handler from shared objects file]
[Loaded java.util.HashSet from shared objects file]
[Loaded sun.misc.URLClassPath from shared objects file]
[Loaded java.util.ArrayList from shared objects file]
[Loaded sun.net.www.protocol.jar.Handler from shared objects file]
[Loaded sun.misc.Launcher$AppClassLoader from shared objects file]
[Loaded sun.misc.Launcher$AppClassLoader$1 from shared objects file]
[Loaded java.lang.SystemClassLoaderAction from shared objects file]
[Loaded java.net.URLClassLoader$1 from shared objects file]
[Loaded sun.misc.URLClassPath$3 from shared objects file]
[Loaded sun.misc.URLClassPath$Loader from shared objects file]
[Loaded sun.misc.URLClassPath$JarLoader from shared objects file]
[Loaded sun.misc.FileURLMapper from shared objects file]
[Loaded java.util.zip.ZipConstants from shared objects file]
[Loaded java.util.zip.ZipFile from shared objects file]
[Loaded java.util.jar.JarFile from shared objects file]
[Loaded sun.security.action.LoadLibraryAction from shared objects file]
[Loaded sun.misc.JavaUtilJarAccess from shared objects file]
[Loaded java.util.jar.JavaUtilJarAccessImpl from shared objects file]
[Loaded sun.misc.JarIndex from shared objects file]
[Loaded sun.misc.ExtensionDependency from shared objects file]
[Loaded java.util.zip.ZipEntry from shared objects file]
[Loaded java.util.jar.JarEntry from shared objects file]
[Loaded java.util.jar.JarFile$JarFileEntry from shared objects file]
[Loaded java.io.DataInput from shared objects file]
[Loaded java.io.DataInputStream from shared objects file]
[Loaded java.util.zip.ZipFile$ZipFileInputStream from shared objects fil
[Loaded java.util.zip.InflaterInputStream from shared objects file]
[Loaded java.util.zip.ZipFile$2 from shared objects file]
[Loaded java.util.zip.Inflater from shared objects file]
[Loaded java.lang.Math from shared objects file]
[Loaded java.security.PrivilegedActionException from shared objects file
[Loaded sun.misc.URLClassPath$FileLoader from shared objects file]
[Loaded java.io.Reader from shared objects file]
[Loaded java.io.BufferedReader from shared objects file]
[Loaded java.io.InputStreamReader from shared objects file]
[Loaded sun.nio.cs.StreamDecoder from shared objects file]
[Loaded sun.nio.cs.HistoricallyNamedCharset from shared objects file]
[Loaded sun.nio.cs.UTF_8 from shared objects file]
[Loaded sun.nio.cs.StreamDecoder$CharsetSD from shared objects file]
[Loaded sun.nio.cs.UTF_8$Decoder from shared objects file]
[Loaded sun.nio.cs.Surrogate$Generator from shared objects file]
[Loaded java.util.AbstractSequentialList from shared objects file]
[Loaded java.util.Queue from shared objects file]
[Loaded java.util.LinkedList from shared objects file]
[Loaded java.util.LinkedList$Entry from shared objects file]
Exception in thread "main" java.lang.NoClassDefFoundError: HelloWord
[Loaded java.lang.Shutdown from shared objects file]
[Loaded java.lang.Shutdown$Lock from shared objects file]
呵呵 已经显示不完了 不过大家可以编译一个更小点的类l；