系統自帶的JDK
[[email protected] ~]# java -version
java version "1.5.0"
gij (GNU libgcj) version 4.4.7 20120313 (Red Hat 4.4.7-3)
Copyright (C) 2007 Free Software Foundation, Inc.
This is free software; see the source for copying
conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.
自己配置的jdk
[[email protected] ~]$ echo $JAVA_HOME
/usr/java/jdk1.8.0_60
但是系統預設的用的是系統自帶的jdk，下面切換到安裝的jdk版本
[[email protected] ~]# alternatives --install /usr/bin/java java
/usr/java/jdk1.8.0_60/bin/java 300
[[email protected] ~]# alternatives --config java
There are 2 programs which provide 'java'.
Selection Command
-----------------------------------------------
*+ 1
/usr/lib/jvm/jre-1.5.0-gcj/bin/java
2 /usr/java/jdk1.8.0_60/bin/java
Enter to keep the current selection[+], or type selection
number: 2
系統自帶的jdk時，是帶gij的，輸入java指令如下：
[[email protected] ~]# java -version
java version "1.5.0"
gij (GNU libgcj) version 4.4.7 20120313 (Red Hat 4.4.7-3)
Copyright (C) 2007 Free Software Foundation, Inc.
This is free software; see the source for copying
conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.
自己安裝的jdk，輸入java指令如下：
[[email protected] ~]# java -version
java version "1.8.0_60"
Java(TM) SE Runtime Environment (build 1.8.0_60-b27)
Java HotSpot(TM) 64-Bit Server VM (build 25.60-b23, mixed
mode)