1.安装的操作系统是centos7.4
[root@iz2ze8a01m28p14ttwjg27z profile.d]# uname -a
Linux iz2ze8a01m28p14ttwjg27z 3.10.0-693.2.2.el7.x86_64 #1 SMP Tue Sep 12 22:26:13 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux
[root@iz2ze8a01m28p14ttwjg27z profile.d]# cat /proc/version
Linux version 3.10.0-693.2.2.el7.x86_64 (builder@kbuilder.dev.centos.org) (gcc version 4.8.5 20150623 (Red Hat 4.8.5-16) (GCC) ) #1 SMP Tue Sep 12 22:26:13 UTC 2017
[root@iz2ze8a01m28p14ttwjg27z profile.d]# lsb_release -a
LSB Version: :core-4.1-amd64:core-4.1-noarch
Distributor ID: CentOS
Description: CentOS Linux release 7.4.1708 (Core)
Release: 7.4.1708
Codename: Core
2.安装java8 和 java11
下载：
wget --no-cookies --no-check-certificate --header "Cookie: gpw_e24=http%3A%2F%2Fwww.oracle.com%2F; oraclelicense=accept-securebackup-cookie" "http://download.oracle.com/otn-pub/java/jdk/11.0.1+13/90cf5d8f270a4347a95050320eef3fb7/jdk-11.0.1_linux-x64_bin.rpm"
安装：
rpm -ivh jdk-8u191-linux-x64.rpm
rpm -ivh jdk-11.0.1_linux-x64_bin.rpm
3.多版本配置
3.1 环境变量配置
在/etc/profile.d/路径下新建一个文件，名为java.sh
#!/bin/bash
export JAVA_HOME=/usr/java/jdk1.8.0_191-amd64
export JRE_HOME=$JAVA_HOME/jre
export PATH=$PATH:$JAVA_HOME/bin
export CLASSPATH=.:$JAVA_HOME/lib:$JRE_HOME/lib
添加执行权限：
chmod +x /etc/profile.d/java.sh
执行source使改动生效：
source /etc/profile.d/java.sh
3.2 配置多版本Java
alternatives --install /usr/bin/java java /usr/java/jdk1.8.0_191-amd64/bin/java 200
alternatives --install /usr/bin/java java /usr/java/jdk-11.0.1/bin/java 300
选择一个：
alternatives --config java
There are 3 programs which provide 'java'.
Selection Command
-----------------------------------------------
* 1 /usr/java/jdk1.8.0_191-amd64/jre/bin/java
2 /usr/java/jdk-11.0.1/bin/java
+ 3 /usr/java/jdk1.8.0_191-amd64/bin/java
Enter to keep the current selection[+], or type selection number:
4.安装asmtools
4.1 安装Mercurial (hg)3.9.2版
Mercurial是一种轻量级分布式版本控制系统，采用Python语言实现。
yum install hg
版本是2.6.2，发现不是最新版，去官方下载centos 7最新版3.9.2
wget https://www.mercurial-scm.org/release/centos7/RPMS/x86_64/mercurial-3.9.2-1.x86_64.rpm
升级2.6.2 到3.9.2
rpm -Uvh mercurial-3.9.2-1.x86_64.rpm
4.2 安装asmtools
hg clone http://hg.openjdk.java.net/code-tools/asmtools/ asmtools
cd asmtools/build/
yum install ant
ant //编译生成asmtools.jar
