Bii o ṣe le Fi Java sii pẹlu Apt lori Ubuntu 20.04

Java jẹ ọkan ninu awọn ede siseto ti o gbajumọ julọ ati JVM (ẹrọ foju Java) jẹ agbegbe asiko-ṣiṣe lati ṣiṣe awọn ohun elo Java. Awọn iru ẹrọ meji wọnyi nilo fun sọfitiwia olokiki pupọ ti o pẹlu Tomcat, Jetty, Cassandra, Glassfish, ati Jenkins.

Ninu nkan yii, iwọ yoo kọ bi o ṣe le fi sori ẹrọ Ayika asiko Rere Java (JRE) ati Ohun elo Olùgbéejáde Java (JDK) nipa lilo oluṣakoso package apt aiyipada lori Ubuntu 20.04 ati Ubuntu 18.04.

Fifi aiyipada JRE ni Ubuntu sii

Ọna ti ko ni irora fun fifi Java sori ẹrọ ni lati lo ẹya ti o wa pẹlu awọn ibi ipamọ Ubuntu. Nipa aiyipada, awọn idii Ubuntu pẹlu OpenJDK 11, eyiti o jẹ yiyan orisun-ṣiṣi ti JRE ati JDK.

Lati fi aiyipada Ṣii JDK 11 sii, kọkọ ṣe imudojuiwọn itọka package sọfitiwia:

$ sudo apt update

Nigbamii, ṣayẹwo fun fifi sori Java lori eto naa.

$ java -version

Ti Java ko ba fi sii lọwọlọwọ, iwọ yoo gba iṣelọpọ wọnyi.

Command 'java' not found, but can be installed with:

sudo apt install openjdk-11-jre-headless  # version 11.0.10+9-0ubuntu1~20.04, or
sudo apt install default-jre              # version 2:1.11-72
sudo apt install openjdk-8-jre-headless   # version 8u282-b08-0ubuntu1~20.04
sudo apt install openjdk-13-jre-headless  # version 13.0.4+8-1~20.04
sudo apt install openjdk-14-jre-headless  # version 14.0.2+12-1~20.04

Bayi ṣiṣe aṣẹ atẹle lati fi sori ẹrọ aiyipada OpenJDK 11, eyi ti yoo pese Ayika Ibugbe Java (JRE).

$ sudo apt install default-jre

Lọgan ti a fi Java sori ẹrọ, o le rii daju fifi sori ẹrọ pẹlu:

$ java -version

Iwọ yoo gba abajade wọnyi:

openjdk version "11.0.10" 2021-01-19
OpenJDK Runtime Environment (build 11.0.10+9-Ubuntu-0ubuntu1.20.04)
OpenJDK 64-Bit Server VM (build 11.0.10+9-Ubuntu-0ubuntu1.20.04, mixed mode, sharing)

Fifi aiyipada JDK sii ni Ubuntu

Lọgan ti fi sori ẹrọ JRE, o le tun nilo JDK (Ohun elo Idagbasoke Java) lati ṣajọ ati ṣiṣe ohun elo ti o da lori Java. Lati fi JDK sori ẹrọ, ṣiṣe aṣẹ atẹle.

$ sudo apt install default-jdk

Lẹhin fifi sori ẹrọ, ṣayẹwo fifi sori JDK nipasẹ ṣayẹwo ẹya naa bi o ti han.

$ javac -version

Iwọ yoo gba abajade wọnyi:

javac 11.0.10

Ṣiṣeto Iyipada Ayika JAVA_HOME ni Ubuntu

Pupọ julọ awọn eto sọfitiwia ti o da lori Java lo oniyipada ayika JAVA_HOME lati ṣawari ipo fifi sori Java.

Lati ṣeto iyipada ayika JAVA_HOME, akọkọ, ṣe iwari ibiti o ti fi Java sii nipa ṣiṣe pipaṣẹ atẹle.

$ readlink -f /usr/bin/java

Iwọ yoo gba abajade wọnyi:

/usr/lib/jvm/java-11-openjdk-amd64/bin/java

Lẹhinna ṣii/ati be be lo/faili ayika nipa lilo olootu ọrọ nano:

$ sudo nano /etc/environment

Ṣafikun laini atẹle ni opin faili naa, rii daju lati rọpo ipo ti ọna fifi sori Java rẹ.

JAVA_HOME="/usr/lib/jvm/java-11-openjdk-amd64"

Fipamọ faili naa ki o tun gbe faili naa lati lo awọn ayipada si igba lọwọlọwọ rẹ:

$ source /etc/environment

Daju pe a ti ṣeto oniyipada ayika:

$ echo $JAVA_HOME

Iwọ yoo gba abajade wọnyi:

/usr/lib/jvm/java-11-openjdk-amd64

Ninu ẹkọ yii, o kọ bi o ṣe le fi sori ẹrọ Ayika asiko asiko Java (JRE) ati Ohun elo Olùgbéejáde Java (JDK) lori Ubuntu 20.04 ati Ubuntu 18.04.