软件包分层结构：
java.applet, java.awt, java.awt.color, java.awt.datatransfer, java.awt.dnd, java.awt.event, java.awt.font, java.awt.geom, java.awt.im, java.awt.im.spi, java.awt.image, java.awt.image.renderable, java.awt.print, java.beans, java.beans.beancontext, java.io, java.lang, java.lang.annotation, java.lang.instrument, java.lang.management, java.lang.ref, java.lang.reflect, java.math, java.net, java.nio, java.nio.channels, java.nio.channels.spi, java.nio.charset, java.nio.charset.spi, java.rmi, java.rmi.activation, java.rmi.dgc, java.rmi.registry, java.rmi.server, java.security, java.security.acl, java.security.cert, java.security.interfaces, java.security.spec, java.sql, java.text, java.text.spi, java.util, java.util.concurrent, java.util.concurrent.atomic, java.util.concurrent.locks, java.util.jar, java.util.logging, java.util.prefs, java.util.regex, java.util.spi, java.util.zip, javax.accessibility, javax.activation, javax.activity, javax.annotation, javax.annotation.processing, javax.crypto, javax.crypto.interfaces, javax.crypto.spec, javax.imageio, javax.imageio.event, javax.imageio.metadata, javax.imageio.plugins.bmp, javax.imageio.plugins.jpeg, javax.imageio.spi, javax.imageio.stream, javax.jws, javax.jws.soap, javax.lang.model, javax.lang.model.element, javax.lang.model.type, javax.lang.model.util, javax.management, javax.management.loading, javax.management.modelmbean, javax.management.monitor, javax.management.openmbean, javax.management.relation, javax.management.remote, javax.management.remote.rmi, javax.management.timer, javax.naming, javax.naming.directory, javax.naming.event, javax.naming.ldap, javax.naming.spi, javax.net, javax.net.ssl, javax.print, javax.print.attribute, javax.print.attribute.standard, javax.print.event, javax.rmi, javax.rmi.CORBA, javax.rmi.ssl, javax.script, javax.security.auth, javax.security.auth.callback, javax.security.auth.kerberos, javax.security.auth.login, javax.security.auth.spi, javax.security.auth.x500, javax.security.cert, javax.security.sasl, javax.sound.midi, javax.sound.midi.spi, javax.sound.sampled, javax.sound.sampled.spi, javax.sql, javax.sql.rowset, javax.sql.rowset.serial, javax.sql.rowset.spi, javax.swing, javax.swing.border, javax.swing.colorchooser, javax.swing.event, javax.swing.filechooser, javax.swing.plaf, javax.swing.plaf.basic, javax.swing.plaf.metal, javax.swing.plaf.multi, javax.swing.plaf.synth, javax.swing.table, javax.swing.text, javax.swing.text.html, javax.swing.text.html.parser, javax.swing.text.rtf, javax.swing.tree, javax.swing.undo, javax.tools, javax.transaction, javax.transaction.xa, javax.xml, javax.xml.bind, javax.xml.bind.annotation, javax.xml.bind.annotation.adapters, javax.xml.bind.attachment, javax.xml.bind.helpers, javax.xml.bind.util, javax.xml.crypto, javax.xml.crypto.dom, javax.xml.crypto.dsig, javax.xml.crypto.dsig.dom, javax.xml.crypto.dsig.keyinfo, javax.xml.crypto.dsig.spec, javax.xml.datatype, javax.xml.namespace, javax.xml.parsers, javax.xml.soap, javax.xml.stream, javax.xml.stream.events, javax.xml.stream.util, javax.xml.transform, javax.xml.transform.dom, javax.xml.transform.sax, javax.xml.transform.stax, javax.xml.transform.stream, javax.xml.validation, javax.xml.ws, javax.xml.ws.handler, javax.xml.ws.handler.soap, javax.xml.ws.http, javax.xml.ws.soap, javax.xml.ws.spi, javax.xml.xpath, org.ietf.jgss, org.omg.CORBA, org.omg.CORBA_2_3, org.omg.CORBA_2_3.portable, org.omg.CORBA.DynAnyPackage, org.omg.CORBA.ORBPackage, org.omg.CORBA.portable, org.omg.CORBA.TypeCodePackage, org.omg.CosNaming, org.omg.CosNaming.NamingContextExtPackage, org.omg.CosNaming.NamingContextPackage, org.omg.Dynamic, org.omg.DynamicAny, org.omg.DynamicAny.DynAnyFactoryPackage, org.omg.DynamicAny.DynAnyPackage, org.omg.IOP, org.omg.IOP.CodecFactoryPackage, org.omg.IOP.CodecPackage, org.omg.Messaging, org.omg.PortableInterceptor, org.omg.PortableInterceptor.ORBInitInfoPackage, org.omg.PortableServer, org.omg.PortableServer.CurrentPackage, org.omg.PortableServer.POAManagerPackage, org.omg.PortableServer.POAPackage, org.omg.PortableServer.portable, org.omg.PortableServer.ServantLocatorPackage, org.omg.SendingContext, org.omg.stub.java.rmi, org.w3c.dom, org.w3c.dom.bootstrap, org.w3c.dom.events, org.w3c.dom.ls, org.xml.sax, org.xml.sax.ext, org.xml.sax.helpers
