???????????jdk
????http://www.oracle.com/technetwork/java/javase/downloads/jdk7-downloads-1880260.html
???????? ???
??????/usr?????java????У????????????/usr/java????
????# mkdir /usr/java
??????????
????//  # chmod 777 jdk-1_5_0_14-linux-i586-rpm.bin    ← ?????????
????//   # ./jdk-1_5_0_14-linux-i586-rpm.bin        ← ???yes????????Э??
????# rpm -ivh  jdk-7u15-linux-x64.rpm  ??????
????????????????????rpm???????root??????????????????error: can't create transaction lock on /var/lib/rpm/__db.000???????????root????????????????ò?????????????????.tar.gz??????
????????????????????.tar.gz?????????????????????????????
????tar   -xvzf  jdk-7u51-linux-x64.gz ?????????????????????????ò??裺
????export JAVA_HOME=/home/ycai/opt/jdk1.7.0_51
????export PATH=$JAVA_HOME/bin:$PATH
????export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar
??????????????????
??????
??????????????
????#java -version
???????
????java version "1.7.0"
????Java(TM) SE Runtime Environment (build 1.7.0-b147)
????Java HotSpot(TM) 64-Bit Server VM (build 21.0-b17?? mixed mode)
??????. ???????????????
????1. PATH???????????????????????????·??????shell??????????????????PATH???????????·???в????????????????????????????????? jdk??????μ?bin??????????е?PATH?????У?bin???а??????????????????????javac/java/javadoc????????ú? PATH?????????????κ????????javac/java????????
????2. CLASSPATH?????????????????????????·?????????????д????????????????????????JVM?????CLASSPTH????????????? ?????jdk??????μ?lib?????е?dt.jar??tools.jar?????CLASSPATH?У???????????“.”??????????????С?
????3. JAVA_HOME???????????????jdk????????Eclipse/NetBeans/Tomcat??????????????JAVA_HOME?????????????e?????jdk??