一、安装jdk9

方法一

sudo apt install openjdk-9-jdk-headless

方法二

下载jdk9:

hg clone http://hg.openjdk.java.net/jdk9/jdk9 openjdk9

cd openjdk9 && sh ./get_source.sh

# 编译

bash ./configure

# make

make all

cd build/linux-x86_64-normal-server-release/images/

# 使用jshell

jdk/bin/jshell

二、试验Jshell

打印一个hello world

试验了一下Calendar类

# dpc @ dpc-thinkpad in /export/service/kulla-dev/openjdk9/build/linux-x86_64-normal-server-release/jdk [22:20:23] $ bin/jshell |  Welcome to JShell -- Version 9-internal|  For an introduction type: /help introjshell> System.out.println("hello world")hello worldjshell> CalCalendar   Callable   jshell> CalCalendar   Callable   jshell> Calendar.getgetAvailableCalendarTypes()   getAvailableLocales()         getInstance(                  jshell> Calendar.getInstance(getInstance(   jshell> Calendar.getInstance()$2 ==> java.util.GregorianCalendar[time=1476195674501,areFieldsSet=true,areAllFieldsSet=true,lenient=true,zone=sun.util.calendar.ZoneInfo[id="Asia/Shanghai",offset=28800000,dstSavings=0,useDaylight=false,transitions=19,lastRule=null],firstDayOfWeek=1,minimalDaysInFirstWeek=1,ERA=1,YEAR=2016,MONTH=9,WEEK_OF_YEAR=42,WEEK_OF_MONTH=3,DAY_OF_MONTH=11,DAY_OF_YEAR=285,DAY_OF_WEEK=3,DAY_OF_WEEK_IN_MONTH=2,AM_PM=1,HOUR=10,HOUR_OF_DAY=22,MINUTE=21,SECOND=14,MILLISECOND=501,ZONE_OFFSET=28800000,DST_OFFSET=0]jshell> Calendar.getInstance().get(Display all 447 possibilities? (y or n)jshell> Calendar.getInstance().get(Cal)Calendar   Callable   jshell> Calendar.getInstance().get(Calendar.D)DATE                   DAY_OF_MONTH           DAY_OF_WEEK            DAY_OF_WEEK_IN_MONTH   DAY_OF_YEAR            DECEMBER               DST_OFFSET             jshell> Calendar.getInstance().get(Calendar.DA)DATE                   DAY_OF_MONTH           DAY_OF_WEEK            DAY_OF_WEEK_IN_MONTH   DAY_OF_YEAR            jshell> Calendar.getInstance().get(Calendar.DAY_OF_)DAY_OF_MONTH           DAY_OF_WEEK            DAY_OF_WEEK_IN_MONTH   DAY_OF_YEAR            jshell> Calendar.getInstance().get(Calendar.DAY_OF_WEEK)DAY_OF_WEEK            DAY_OF_WEEK_IN_MONTH   jshell> Calendar.getInstance().get(Calendar.DAY_OF_WEEK))$3 ==> 3jshell> Calendar.getInstance().get(Calendar.DAY_OF_MONTH)$4 ==> 11jshell> Calendar.getInstance().get(Calendar.DAY_OF_YEAR)$5 ==> 285jshell> Calendar.getInstance().get(Calendar.HOUR)HOUR          HOUR_OF_DAY   jshell> Calendar.getInstance().get(Calendar.HOUR))$6 ==> 10