下載Java 9
openjdk: http://jdk.java.net/
sunjdk: http://www.oracle.com/technetwork/java/javase/downloads/jdk9-downloads-3848520.html
(wget --no-check-certificate --no-cookies --header "Cookie: oraclelicense=accept-securebackup-cookie" http://download.oracle.com/otn-pub/java/jdk/9+181/jdk-9_linux-x64_bin.tar.gz)
配置環境變量
export JAVA_HOME=/usr/local/jdk-9
#export JRE_HOME=/usr/local/jre-9#openjdk
#export JRE_HOME=/usr/disk/jre-9#openjdk
export PATH=$JAVA_HOME/bin:$JRE_HOME/bin:$PATH
export CLASSPATH=.:$JAVA_HOME/lib:$JRE_HOME/lib:$CLASSPATH
/usr/sbin/alternatives--install/usr/bin/javajava/usr/java/jdk-9/bin/java19000
/usr/sbin/alternatives--install/usr/bin/javacjavac/usr/java/jdk-9/bin/javac19000
# java -version
java version"9"
Java(TM)SE Runtime Environment (build 9+179)
Java HotSpot(TM)64-Bit Server VM (build 9+179, mixed mode)
# javac -version
javac9
java的位置
# whereis java
java: /usr/bin/java /usr/local/java /usr/local/jdk-9/bin/java /usr/local/jre-9/bin/java /usr/local/java/jdk1.7.0_75/bin/java
java實際的執行路徑
# which java
/usr/local/jdk-9/bin/java
如果使用的是最後兩句的方式,查看java實際的執行路徑是命令中指定的路徑
# which java
/usr/bin/java