???????????class???
??????д?main??????class??????????????
????java <CLASS?????>
???????CLASS????????????????.class
???????磺
????????????:
????java Test
?????????е?class????????????????????????????package <????>
???????????????·??????У??????????
????java <????>.CLASS?????
???????磺PackageTest.java?У?????????com.ee2ee.test?????????????
????package com.ee2ee.test;
????PackageTest.java????????class???PackageTest.class?????????￡?
????classes
????|__com
????|__ee2ee
????|__test
????|__PackageTest.java
????|__PackageTest.class
?????????PackageTest.class?????classes??????У?
????????????:
????java com.ee2ee.test.PackageTest
????????????jar????е?class
????????????class??????????????????-cp <jar?????>???ɡ?
???????磺???test.jar?е???com.ee2ee.test.PackageTest???????????￡?
????????????:
????java -cp test.jar com.ee2ee.test.PackageTest
???????????jdk?汾???
???????????????ж??jdk?汾??????????????????????汾??jdk????ò???-version?????????汾???????????
????????????:
????java -version
????????????????????????????
????java????????????????????????????????64MB??128MB??????????ó???????????????????????????ж???y?????棬???糬??????????128MB????????java??????????????棬????????Out of Memory??????治???????????java???????????????????????
????-Xms java???????????????????С
????-Xmx java?????????????????
???????????????????????size?????????λ?????磺256m???256MB
?????????????
????????????:
????java -Xms128m -Xmx256m ...
???????java???????????????????128MB?????????????256MB??
????????tomcat?????????????catalina.sh??unix??????catalina.bat??windows?????????????JAVA_OPTS????????磺
????????????:
????JAVA_OPTS='-Xms128m -Xmx256m'
?????????????????У??и?-X????????д????????????????JVM???ò????????
??????Σ???java -X ?????JVM???????????
????1??-Xmixed mixed mode execution (default)
????????????
????2??-Xint interpreted mode execution only
?????????????
????3??-Xbootclasspath:<directories and zip/jar files separated by ;>
????set search path for bootstrap classes and resources
????????zip/jar?????????.class??????????·??
????3??-Xbootclasspath/a:<directories and zip/jar files separated by ;>
????append to end of bootstrap class path
???????zip/jar?????????.class??????????·??
????4??-Xbootclasspath/p:<directories and zip/jar files separated by ;>
????prepend in front of bootstrap class path
??????????zip/jar?????????.class??????????·??