Installing JDK under Linux

Before installing, check that the system has a JDK installed

Rpm-qa | grep java

If you can use Rpm-qa | grep Java | Xargs rpm-e--nodeps bulk unload all files with Java

Download on official website

1.

Http://www.oracle.com/technetwork/java/javase/downloads/java-archive-downloads-javase7-521261.html

Installation:

RPM (Recommended with RPM package installation):

1. Copy the RPM package to the/usr/java path

Mkdir/usr/java

CP jdk-7u55-linux-x64.rpm/usr/java/

2. Add executable permissions and install:

cd/usr/java/

chmod +x jdk-7u55-linux-x64.rpm

RPM-IVH jdk-7u55-linux-x64.rpm

[Email protected] src]# RPM-IVH jdk-7u55-linux-x64.rpm

Preparing ... ########################################### [100%]

1:JDK ########################################### [100%]

Unpacking JAR files ...

Rt.jar ...

Jsse.jar ...

Charsets.jar ...

Tools.jar ...

Localedata.jar ...

Jfxrt.jar ...

RPM package installation is automatically extracted to the/usr/java/directory:

[Email protected] ~]# cd/usr/java/

[email protected] java]# LL

Total Dosage 4

lrwxrwxrwx 1 root root 16 January, default--/usr/java/latest

Drwxr-xr-x 8 root root 4096 January jdk1.7.0_55

lrwxrwxrwx 1 root root 21 January latest-/usr/java/jdk1.7.0_55

3. Configure Environment variables

Law One:

To edit a profile:

Vim/etc/profile

At the end of the profile file, append the following:

Export java_home=/usr/java/jdk1.7.0_55

Export path= $JAVA _home/bin: $PATH

Export classpath=.: $JAVA _home/jre/lib/rt.jar: $JAVA _home/lib/dt.jar: $JAVA _home/lib/tools.jar

Save and exit, execute

Source/etc/profile

Law II:

vim/etc/profile.d/java.sh

Exportjava_home=/usr/java/jdk1.8.0_40

Exportpath= $JAVA _home/bin: $PATH

Exportclasspath=.: $JAVA _home/lib/dt.jar: $JAVA _home/lib/tools.jar

source/etc/profile.d/java.sh

4. View Java version

[Email protected] ~]# java-version

Java Version "1.7.0_55"

Java (TM) SE Runtime Environment (build 1.7.0_55-b13)

Java HotSpot (TM) 64-bit Server VM (build 24.55-b03, Mixed mode)

[email protected] ~]# which Java

/usr/bin/java

[Email protected] ~]# Ls-lrt/usr/bin/java

lrwxrwxrwx 1 root root 26 January 06:00/usr/bin/java-/usr/java/default/bin/java

tar.gz

1: Download the JDK Package: This chapter uses a file with the suffix tar.gz (no installation required), such as jdk-7u80-linux-x64.tar.gz

2: Save the JDK file to the Linux directory: Use the mkdir command to generate the/usr/java directory from the console, and put the file under it

3: Unzip the tar.gz file: Through the console, enter the/usr/java, execute, unzip it

4: Configure Environment variables: Open the console, run Vi/etc/profile, insert the content you want to configure at the end, press ESC, enter (: Wq Save and exit)

Export java_home=/usr/java/jdk1.7.0_80

Export path= $JAVA _home/bin: $PATH

Export classpath=.: $JAVA _home/jre/lib/rt.jar: $JAVA _home/lib/dt.jar: $JAVA _home/lib/tools.jar

5: Run Source/etc/profile to make the configuration environment effective

6: Run java-version See if it takes effect. If the JDK version number appears, install and configure the environment variable successfully

How Linux looks at the JDK installation path

1:echo $JAVA _home

If you use $java_home, you can locate the installation path of the JDK as long as the environment variable $java_home is configured, otherwise the installation path of the JDK is not located at all.

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[Email protected] ~]# java-version

Java Version "1.7.0_55"

Java (TM) SE Runtime Environment (build 1.7.0_55-b13)

Java HotSpot (TM) 64-bit Server VM (build 24.55-b03, Mixed mode)

[Email protected] ~]# echo $JAVA _home

Installing JDK under Linux