????????2????ClassLoaderTest.class?????ClassLoaderTest.jar?????Extension ClassLoader????????￡?JAVA_HOME/jre/lib/ext????????????????????????????????????????

????????????

????????????????
???????????е?????ExtClassLoader???
???????ClassLoader?????????????????????ClassLoaderTest.class?????????AppClassLoader?????????????????и?Bootstrcp ClassLoader??Bootstracp ClassLoader???????????????????ExtClassLoader???????????????????????????????????Extension ClassLoader???????????????????·????JAVA_HOME/jre/lib/ext??????????????????????ClassLoaderTest.jar???????????а???ClassLoaderTest.class?????????????????????????????????????浱?У?????????????Class?????????????????????????ClassLoaderTest.class???????????ExtClassLoader??
????????е????null???????ExtClassLoader????????????Bootstrap ClassLoader??
????????3????Bootstrcp ClassLoader??????ClassLoaderTest.class????????????
????1????jvm?????-Xbootclasspath?????????Bootstrcp ClassLoader???????·??????????????????jar??ClassTestLoader.jar??
????2????class??????JAVA_HOME/jre/classes/???￡???????????
???????1???????????Eclipse?????????????????????java??????????-Xbootclasspath??????
??????Run????????

???????ú????????????????????????г??????????????????????????????????????????
????????????
????[Loaded java.io.FileReader from C:Program FilesJavajdk1.6.0_22jrelib t.jar]
????[Loaded sun.nio.cs.StreamDecoder from C:Program FilesJavajdk1.6.0_22jrelib t.jar]
????[Loaded java.util.ArrayList from C:Program FilesJavajdk1.6.0_22jrelib t.jar]
????[Loaded java.lang.reflect.Array from C:Program FilesJavajdk1.6.0_22jrelib t.jar]
????[Loaded java.util.Locale from C:Program FilesJavajdk1.6.0_22jrelib t.jar]
????[Loaded java.util.concurrent.ConcurrentMap from C:Program FilesJavajdk1.6.0_22jrelib t.jar]
????[Loaded java.util.concurrent.ConcurrentHashMap from C:Program FilesJavajdk1.6.0_22jrelib t.jar]
????[Loaded java.util.concurrent.locks.Lock from C:Program FilesJavajdk1.6.0_22jrelib t.jar]
????[Loaded java.util.concurrent.locks.ReentrantLock from C:Program FilesJavajdk1.6.0_22jrelib t.jar]
????[Loaded java.util.concurrent.ConcurrentHashMap$Segment from C:Program FilesJavajdk1.6.0_22jrelib t.jar]
????[Loaded java.util.concurrent.locks.AbstractOwnableSynchronizer from C:Program FilesJavajdk1.6.0_22jrelib t.jar]
????[Loaded java.util.concurrent.locks.AbstractQueuedSynchronizer from C:Program FilesJavajdk1.6.0_22jrelib t.jar]
????[Loaded java.util.concurrent.locks.ReentrantLock$Sync from C:Program FilesJavajdk1.6.0_22jrelib t.jar]
????[Loaded java.util.concurrent.locks.ReentrantLock$NonfairSync from C:Program FilesJavajdk1.6.0_22jrelib t.jar]
????[Loaded java.util.concurrent.locks.AbstractQueuedSynchronizer$Node from C:Program FilesJavajdk1.6.0_22jrelib t.jar]
????[Loaded java.util.concurrent.ConcurrentHashMap$HashEntry from C:Program FilesJavajdk1.6.0_22jrelib t.jar]
????[Loaded java.lang.CharacterDataLatin1 from C:Program FilesJavajdk1.6.0_22jrelib t.jar]
????[Loaded java.io.ObjectStreamClass from C:Program FilesJavajdk1.6.0_22jrelib t.jar]
????[Loaded sun.net.www.ParseUtil from C:Program FilesJavajdk1.6.0_22jrelib t.jar]
????[Loaded java.util.BitSet from C:Program FilesJavajdk1.6.0_22jrelib t.jar]
????[Loaded java.net.Parts from C:Program FilesJavajdk1.6.0_22jrelib t.jar]
????[Loaded java.net.URLStreamHandler from C:Program FilesJavajdk1.6.0_22jrelib t.jar]
????[Loaded sun.net.www.protocol.file.Handler from C:Program FilesJavajdk1.6.0_22jrelib t.jar]
????[Loaded java.util.HashSet from C:Program FilesJavajdk1.6.0_22jrelib t.jar]
????[Loaded sun.net.www.protocol.jar.Handler from C:Program FilesJavajdk1.6.0_22jrelib t.jar]
????[Loaded sun.misc.Launcher$AppClassLoader from C:Program FilesJavajdk1.6.0_22jrelib t.jar]
????[Loaded sun.misc.Launcher$AppClassLoader$1 from C:Program FilesJavajdk1.6.0_22jrelib t.jar]
????[Loaded java.lang.SystemClassLoaderAction from C:Program FilesJavajdk1.6.0_22jrelib t.jar]
????[Path C:Program FilesJavajdk1.6.0_22jreclasses]
????[Loaded classloader.ClassLoaderTest from C:Program FilesJavajdk1.6.0_22jreclasses]
????null//??????????
????C:Program FilesJavajdk1.6.0_22jrelib esources.jar;C:Program FilesJavajdk1.6.0_22jrelib t.jar;
????C:Program FilesJavajdk1.6.0_22jrelibsunrsasign.jar;C:Program FilesJavajdk1.6.0_22jrelibjsse.jar;
????C:Program FilesJavajdk1.6.0_22jrelibjce.jar;C:Program FilesJavajdk1.6.0_22jrelibcharsets.jar;
????C:Program FilesJavajdk1.6.0_22jreclasses;c:ClassLoaderTest.jar
????//???????System.out.println(System.getProperty("sun.boot.class.path"));?????????????·????Bootstrcp ClassLoader??????????·??
????[Loaded java.lang.Shutdown from C:Program FilesJavajdk1.6.0_22jrelib t.jar]
????[Loaded java.lang.Shutdown$Lock from C:Program FilesJavajdk1.6.0_22jrelib t.jar]
???????2????ClassLoaderTest.jar????????JAVA_HOME/jre/classes???￡???????????
?????????jre??????????classes????????????????????


 

????????????

?????????п??????????????????????ClassLoaderTest.class??Bootstrcp ClassLoader?????????
????????????????ClassLoader
???????JVM?????????????????????????????????????????????
???????Java?????????ClassLoader?????????????μ?jar??class??????????????????λ??????jar??????磺?????????????????class?????????????????????????????????е??????????????????????????????￡?????ClassLoader????????????????????????????????????ClassLoader??
?????????????????????????????
????1?????java.lang.ClassLoader
????2????д?????findClass????