Install jdk< on CentOS Linux via yum >

Uninstall the JDK that comes with CentOS

1. Review the current JDK version and uninstall

[[email protected] opt]#  rpm -qa|grep java java-1.6.0-openjdk-1.6.0.37-1.13.9.4.el5_11tzdata-java-2015g-1.el5//卸载[[email protected] opt]# rpm -e --allmatches --nodeps java-1.6.0-openjdk-1.6.0.37-1.13.9.4.el5_11[[email protected] opt]# rpm -e --allmatches --nodeps tzdata-java-2015g-1.el5

Installing the JDK

1. Find Java-related lists

[[email protected] jre-1.6.0-openjdk.x86_64]# yum -y list java*loaded  plugins: fastestmirrorloading mirror speeds from cached hostfile *  addons: mirrors.btte.net * base: centos.ustc.edu.cn * extras:  Centos.ustc.edu.cn * updates: centos.ustc.edu.cninstalled packagesjava-1.6.0-openjdk.x86_ 64                                          1:1.6.0.37-1.13.9.4.el5_11                                installedAvailable Packagesjava-1.4.2-gcj-compat.x86_64                                       1.4.2.0-40jpp.115                                         base      java-1.4.2-gcj-compat-devel.i386                                   1.4.2.0-40jpp.115                                         base      java-1.4.2-gcj-compat-devel.x86_64                                1.4.2.0-40jpp.115                                         base      java-1.4.2-gcj-compat-javadoc.x86_64                               1.4.2.0-40jpp.115                                         base      Java-1.4.2-gcj-compat-src.x86_64                                  1.4.2.0-40jpp.115                                          base     java-1.6.0-openjdk-demo.x86_64                                     1:1.6.0.37-1.13.9.4.el5_11                                updates  java-1.6.0-openjdk-devel.x86_64                                    1:1.6.0.37-1.13.9.4.el5_11                                updates  java-1.6.0-openjdk-javadoc.x86_64                                  1:1.6.0.37-1.13.9.4.el5_11                                updates  java-1.6.0-openjdk-src.x86_64                        &Nbsp;             1:1.6.0.37-1.13.9.4.el5_11                                updates   java-1.7.0-openjdk.x86_64                                          1:1.7.0.91-2.6.2.1.el5_11                                 updates  java-1.7.0-openjdk-demo.x86_64                                     1:1.7.0.91-2.6.2.1.el5_11                                 updates  java-1.7.0-openjdk-devel.x86_64                                    1:1.7.0.91-2.6.2.1.el5_11                                 updates   java-1.7.0-openjdk-javadoc.x86_64                                  1:1.7.0.91-2.6.2.1.el5_11                                updates   java-1.7.0-openjdk-src.x86_64                                      1:1.7.0.91-2.6.2.1.el5_11                                 updates  java_cup.x86_64                                                     1:0.10-0.k.6jpp.1                                         base     java_cup-javadoc.x86_64                                             1:0.10-0.k.6jpp.1                                         base     java_cup-manual.x86_64                                              1:0.10-0.k.6jpp.1                                         base     javacc.x86_64                                                       4.0-3jpp.3                                                 base     javacc-demo.x86_64                                                  4.0-3jpp.3                                                base      javacc-manual.x86_64                                               4.0-3jpp.3                                                 base

       

[[Email protected] jre-1.6.0-openjdk.x86_64]# yum search jdkloaded plugins:  fastestmirrorloading mirror speeds from cached hostfile * addons:  mirrors.btte.net * base: centos.ustc.edu.cn * extras: centos.ustc.edu.cn  * updates: centos.ustc.edu.cn==========================================================  Matched: jdk ==========================================================java-1.6.0-openjdk.x86_64  : OpenJDK Runtime Environmentjava-1.6.0-openjdk-demo.x86_64 : OpenJDK  demosjava-1.6.0-openjdk-devel.x86_64 : openjdk development  environmentjava-1.6.0-openjdk-javadoc.x86_64 : openjdk api  Documentationjava-1.6.0-openjdk-src.x86_64 : openjdk source bundlejava-1.7.0-openjdk.x86_ 64 : openjdk runtime environmentjava-1.7.0-openjdk-demo.x86_64 : openjdk demosjava-1.7.0-openjdk-devel.x86_64 : openjdk development  environmentjava-1.7.0-openjdk-javadoc.x86_64 : openjdk api  documentationjava-1.7.0-openjdk-src.x86_64 : openjdk source  bundlegnu-crypto-sasl-jdk1.4.x86_64 : gnu crypto sasl  apijakarta-commons-beanutils.x86_64 : jakarta commons beanutils  packagejakarta-commons-collections.x86_64 : jakarta commons collections  packagejakarta-commons-launcher.x86_64 : the launcher component is designed  to be a cross platform Java application launcher.ldapjdk.x86_64  : the mozilla ldap java sdkldapjdk-javadoc.x86_64 : javadoc for  ldapjdkmockobjects-alt-jdk1.4.x86_64 : mockable api for jdk  1.4mockobjects-jdk1.4.x86_64 : mockobjects for 1.4 jdk 

2. Installing the JDK

[[email protected] ~]# yum install java-1.6.0-openjdk.x86_64 …… Total download size: 44 MIs this ok [y/N]: y

3. After the installation is complete, verify that

[[email protected] ~]# java -versionjava version "1.6.0_37"OpenJDK Runtime Environment (IcedTea6 1.13.9) (rhel-1.13.9.4.el5_11-x86_64)OpenJDK 64-Bit Server VM (build 23.25-b01, mixed mode)

4. The path to the default installation via Yum is

/usr/lib/jvm

[[email protected] ~]# cd /usr/lib/jvm[[email protected] jvm]# lltotal 24drwxr-xr-x 3 root root 4096 Jan 12 20:01 java-1.6.0-openjdk-1.6.0.37.x86_64lrwxrwxrwx 1 root root   21 Jan 12 20:01 jre -> /etc/alternatives/jrelrwxrwxrwx 1 root root   27 Jan 12 20:01 jre-1.6.0 -> /etc/alternatives/jre_1.6.0lrwxrwxrwx 1 root root   38 Jan 12 20:01 jre-1.6.0-openjdk.x86_64 -> java-1.6.0-openjdk-1.6.0.37.x86_64/jrelrwxrwxrwx 1 root root   29 Jan 12 20:01 jre-openjdk -> /etc/alternatives/jre_openjdk

If more than one JDK is installed on the machine, the Java command can point to only one version of the JDK, in order to make it easy to modify the JDK version in the global

The/etc/alternatives directory below will have a Java link to the Bin/java command that defaults to the version of the JDK that needs to be executed

[[email protected] jvm]# cd /etc/alternatives[[email protected] alternatives]# lltotal 204lrwxrwxrwx 1 root root 46 Jan 12 20:01 java -> /usr/lib/jvm/jre-1.6.0-openjdk.x86_64/bin/java

And/etc/alternatives/java will be soft connected to/usr/bin/java

[[email protected] alternatives]# cd /usr/bin[[email protected] bin]# ll |grep javalrwxrwxrwx 1 root root         22 Jan 12 20:01 java -> /etc/alternatives/java

5. Add the JDK installation path to the Java_home

Method One:

[[email protected] bin]# vi /etc/profile

At the end of the document, add:

#set java environmentJAVA_HOME=/usr/lib/jvm/jre-1.6.0-openjdk.x86_64PATH=$PATH:$JAVA_HOME/binCLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jarexport JAVA_HOME CLASSPATH PATH

Modify/etc/profile to take effect

[[email protected] alternatives]# . /etc/profile

Attention. Then there should be a space

Method Two:

Or install the form of the Java command above to make it easier to modify

[[email protected] jvm]# cd /etc/alternatives[[email protected] alternatives]# ln -s /usr/lib/jvm/jre-1.6.0-openjdk.x86_64/ java_home

Create a/etc/alternatives/java_home soft connection that points the connection to the root of the current JDK

Then add the path to the connection.

#set java environmentJAVA_HOME=/etc/alternatives/java_homePATH=$PATH:$JAVA_HOME/binCLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jarexport JAVA_HOME CLASSPATH PATH

[[email protected] alternatives]# export |grep JAVA_HOMEdeclare -x JAVA_HOME="/etc/alternatives/java_home"

Install jdk< on CentOS Linux via yum >