????CLASSPATH??Java???????????????????????????????????classpath???????java??ζ?λ??????????

????CLASSPATH????????????????Java??λ????????????Windows?У?????????????->???->??????????????????

????Windows???????? echo %CLASSPATH%?????á?

???????г?????????????????? -cp??????-classpath?????????classpath?????????????????л??????????ò??????ó?????ò????classpath???????

???????磬????

????java -classpath c:classes;c:jarabc.jar;c:zipabc.zip;c:src abc

????????CLASSPATH??????·??????????·???μ???

??????????ж??????????CLASSPATH?????У?Java?????????????в?????????????????δ????????????????????????????????????????????????磺

?????????CLASSPATH=/home/tester/first:/home/tester/second??

??????????2??????汾??test????first??second???У????????java Test?????????java??????????????????first??????????????test??????????????second???в??????

?????????first?????????test????????second???в??????

?????????-jar????????????????????????? CLASSPATH???????????????-cp??-classpath????????????????????￡????????META-INF/MANIFEST.MF?????Class-Path attribute ????classpath

?????????????????????????????CLASSPATH??????????“.”????testing?????????class?Test??????????????C:project estingTest.class???????C:project esting????????????“java Test”??????????

???????????????У???????????????in thread "main" java.lang.NoClassDefFoundError: Test?????????????Test?????? testing.Test ??????classpath??????????????

?????????C:project esting???￡?????????java testing.Test?????????? in thread "main" java.lang.NoClassDefFoundError: testing/Test

?????????????????"."????????testing?????????Test????????????????????C:project esting??????testing??????·????

????????г??????????C:project???￡?????C:project>java testing.Test ?????????