Otu esi etinye Java na Apt na Ubuntu 20.04

Java bụ otu n'ime asụsụ mmemme kachasị ewu ewu yana JVM (igwe mebere Java) bụ ebe a na-agba ọsọ iji mee ngwa Java. Achọrọ nyiwe abụọ a maka sọftụwia ama ama gụnyere Tomcat, Jetty, Cassandra, Glassfish, na Jenkins.

N'isiokwu a, ị ga-amụta ka esi etinye Java Runtime Environment (JRE) na Java Developer Kit (JDK) site na iji njikwa ngwugwu dabara adaba na Ubuntu 20.04 na Ubuntu 18.04.

Wụnye nke ndabara JRE na Ubuntu

Ụzọ na-enweghị mgbu maka ịwụnye Java bụ iji ụdị nke na-abịa na ebe nchekwa Ubuntu. Site na ndabara, ngwugwu Ubuntu nwere OpenJDK 11, nke bụ ụzọ mepere emepe nke JRE na JDK.

Iji wụnye ndabara Mepee JDK 11, buru ụzọ melite ndeksi ngwungwu ngwanrọ:

$ sudo apt update

Ọzọ, lelee maka nrụnye Java na sistemụ.

$ java -version

Ọ bụrụ na arụnyebeghị Java ugbu a, ị ga-enweta nsonaazụ a.

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

Ugbu a gbaa iwu a ka ịwụnye OpenJDK 11 ndabara, nke ga-enye Java Runtime Environment (JRE).

$ sudo apt install default-jre

Ozugbo Java wụnyechara, ịnwere ike iji:

$ java -version

Ị ga-enweta nsonaazụ a:

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)

Ịwụnye JDK Default na Ubuntu

Ozugbo arụnyere JRE, ị nwekwara ike ịchọ JDK (Java Development Kit) iji chịkọta ma mee ngwa dabere na Java. Iji wụnye JDK, mee iwu a.

$ sudo apt install default-jdk

Mgbe echichi gasịrị, nyochaa nrụnye JDK site na ịlele ụdị dị ka egosiri.

$ javac -version

Ị ga-enweta nsonaazụ a:

javac 11.0.10

Ịtọ ntọala JAVA_HOME gburugburu na Ubuntu

Ọtụtụ mmemme sọftụwia dabere na Java na-eji mgbanwe gburugburu JAVA_HOME iji chọpụta ebe nrụnye Java.

Ka ịtọọ mgbanwe gburugburu JAVA_HOME, nke mbụ, chọpụta ebe arụnyere Java site na iji iwu na-esonụ.

$ readlink -f /usr/bin/java

Ị ga-enweta nsonaazụ a:

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

Mepee faịlụ /etc/environment site na iji nchịkọta ederede nano:

$ sudo nano /etc/environment

Tinye ahịrị na-esonụ na njedebe nke faịlụ ahụ, jide n'aka na ị ga-edochi ọnọdụ nke ụzọ ntinye Java gị.

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

Chekwaa faịlụ ma bugharịa faịlụ ka itinye mgbanwe na nnọkọ gị ugbu a:

$ source /etc/environment

Chọpụta na edobere mgbanwe gburugburu:

$ echo $JAVA_HOME

Ị ga-enweta nsonaazụ a:

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

N'ime nkuzi a, ị mụtara ka esi etinye Java Runtime Environment (JRE) na Java Developer Kit (JDK) na Ubuntu 20.04 na Ubuntu 18.04.