Installing JDK and configuring the JDK environment diagram in Linux

Installing JDK and configuring the JDK environment diagram in Linux

One: First detect if the JDK is installed

To run the command:

# Rpm-qa|grep JDK

Or

# rpm-q JDK

Or

#find/-name jdk*

/soft/openfire_java/jdk-7u40-linux-x64.rpm
/usr/java/jdk1.7.0_15
/usr/java/jdk1.7.0_15/jre/lib/servicetag/jdk_header.png
/usr/java/jdk1.7.0_15/lib/visualvm/profiler/lib/deployed/jdk15
/usr/java/jdk1.7.0_15/lib/visualvm/profiler/lib/deployed/jdk16
/usr/java/jdk-7u15-linux-x64.rpm

Assuming that the JDK has been installed, the corresponding JDK version number is displayed as above.

II: Uninstalling the system's own JDK or installed JDK

Uninstall the default:
Log in to the system with the root user and open SSH secure terminal input
# Rpm-qa|grep GCJ
The following two lines of information are included in the display:
# JAVA-1.4.2-GCJ-COMPAT-1.4.2.0-27JPP
# JAVA-1.4.2-GCJ-COMPAT-DEVEL-L.4.2.0-27JPP
Unloading
# RPM-E JAVA-1.4.2-GCJ-COMPAT-DEVEL-L.4.2.0-27JPP
# RPM-E JAVA-1.4.2-GCJ-COMPAT-L.4.2.0-27JPP

Uninstall any other JDK you have installed directly with RPM-E <javaXXXXX>
Uninstall the RPM version of the JDK:

#rpm-qa|grep JDK

Display: jdk-1.7.0_15-fcs.x86_64
Uninstall: #rpm-e--nodeps jdk-1.7.0_15-fcs.x86_64

II: Download and install the JDK

1. Download:

: http://www.oracle.com/technetwork/java/javase/downloads/jdk7-downloads-1880260.html

My system is CentOS linux64, I downloaded the jdk-7u15-linux-x64.rpm

2. Remember to install using the root user.

Download to the Local. rpm file and upload it to the server.

For example: Create a new Java folder in the/usr/folder and upload it to this folder.

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After uploading successfully, go to this folder

#cd/usr/java

installation program
#rpm-IVH jdk-1_5_0-linux-i586.rpm
Install the installation protocol, etc., press accept to be able.

Assuming that a dependency packet error occurs, it is not necessary to ignore it.

3 . Environment variable settings.

#vi/etc/profile
added after export PATH USER LOGNAME MAIL HOSTNAME histsize Histcontrol
Export Java_home=/usr/java/jdk1.7.0_15
Export classpath=.: $JAVA _home/jre/lib/rt.jar: $JAVA _home/lib/dt.jar: $JAVA _home/lib/tools.jar
Export path= $PATH: $JAVA _home/bin
Save exit.
# source/etc/profile # #使环境变量生效
# set
4. Check the Java version number

#java-version

Output:

Java Version "1.7.0_15"
Java (TM) SE Runtime Environment (build 1.7.0_15-b03)
Java HotSpot (TM) 64-bit Server VM (build 23.7-b01, Mixed mode)

Indicates that the JDK was successfully installed

Installing JDK and configuring the JDK environment diagram in Linux