在linux上通过yum安装JDK

川长思鸟来 2022-02-21 13:09 336阅读 0赞

卸载centos自带的jdk

1.查看当前的jdk版本，并卸载

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

安装Jdk

1.查找java相关得列表

[root@localhost jre-1.6.0-openjdk.x86_64]# yum -y list java*
    Loaded plugins: fastestmirror
    Loading mirror speeds from cached hostfile
     * addons: mirrors.btte.net
     * base: centos.ustc.edu.cn
     * extras: centos.ustc.edu.cn
     * updates: centos.ustc.edu.cn
    Installed Packages
    java-1.6.0-openjdk.x86_64                                        1:1.6.0.37-1.13.9.4.el5_11                              installed
    Available Packages
    java-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                                    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

或

[root@localhost jre-1.6.0-openjdk.x86_64]# yum search jdk
    Loaded plugins: fastestmirror
    Loading 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 Environment
    java-1.6.0-openjdk-demo.x86_64 : OpenJDK Demos
    java-1.6.0-openjdk-devel.x86_64 : OpenJDK Development Environment
    java-1.6.0-openjdk-javadoc.x86_64 : OpenJDK API Documentation
    java-1.6.0-openjdk-src.x86_64 : OpenJDK Source Bundle
    java-1.7.0-openjdk.x86_64 : OpenJDK Runtime Environment
    java-1.7.0-openjdk-demo.x86_64 : OpenJDK Demos
    java-1.7.0-openjdk-devel.x86_64 : OpenJDK Development Environment
    java-1.7.0-openjdk-javadoc.x86_64 : OpenJDK API Documentation
    java-1.7.0-openjdk-src.x86_64 : OpenJDK Source Bundle
    gnu-crypto-sasl-jdk1.4.x86_64 : Gnu Crypto SASL API
    jakarta-commons-beanutils.x86_64 : Jakarta Commons BeanUtils Package
    jakarta-commons-collections.x86_64 : Jakarta Commons Collections Package
    jakarta-commons-launcher.x86_64 : The Launcher Component is designed to be a cross platform Java application launcher.
    ldapjdk.x86_64 : The Mozilla LDAP Java SDK
    ldapjdk-javadoc.x86_64 : Javadoc for ldapjdk
    mockobjects-alt-jdk1.4.x86_64 : Mockable API for JDK 1.4
    mockobjects-jdk1.4.x86_64 : MockObjects for 1.4 JDK

2.安装jdk

[root@localhost ~]# yum install java-1.6.0-openjdk.x86_64
     …… 
    Total download size: 44 M
    Is this ok [y/N]: y

3.安装完成之后，验证

[root@localhost ~]# java -version
    java 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.通过yum默认安装的路径为

**  /usr/lib/jvm**

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

如果机器上同时安装了多个jdk的话，java命令只能指向一个版本的jdk，为了在全局中方便修改jdk版本

**   /etc/alternatives** 的目录下面会有个java链接，指向默认需要执行的版本的jdk的**bin/java** 命令

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

而**/etc/alternatives/java**又会被软连接到**/usr/bin/java**

5.将jdk的安装路径加入到JAVA\_HOME

方法一：

[root@localhost bin]# vi /etc/profile

在文件最后加入：

#set java environment
    JAVA_HOME=/usr/lib/jvm/jre-1.6.0-openjdk.x86_64
    PATH=$PATH:$JAVA_HOME/bin
    CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar
    export JAVA_HOME CLASSPATH PATH

修改/etc/profile之后让其生效

[root@localhost alternatives]# . /etc/profile

注意 **. **之后应有一个空格

方法二：

或者是安装上面创建java命令的形式，以方便修改

[root@localhost jvm]# cd /etc/alternatives
    [root@localhost alternatives]# ln -s /usr/lib/jvm/jre-1.6.0-openjdk.x86_64/ java_home

创建一个**/etc/alternatives/java\_home**的软连接，将该连接指向到当前Jdk的根目录

然后将改连接的路径加进去

#set java environment
    JAVA_HOME=/etc/alternatives/java_home
    PATH=$PATH:$JAVA_HOME/bin
    CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar
    export JAVA_HOME CLASSPATH PATH

[root@localhost alternatives]# export |grep JAVA_HOME
    declare -x JAVA_HOME="/etc/alternatives/java_home"