centos下安装jdk

检查yum库中有哪些jdk版本

yum search java|grep jdk 

显示如下：

java-1.6.0-openjdk-debuginfo.x86_64 : Debug information for package                                    : java-1.6.0-openjdkjava-1.7.0-openjdk-debuginfo.x86_64 : Debug information for package                                    : java-1.7.0-openjdkjava-1.7.0-openjdk-debuginfo.i686 : Debug information for package                                  : java-1.7.0-openjdkjava-1.8.0-openjdk-debuginfo.x86_64 : Debug information for package                                    : java-1.8.0-openjdkldapjdk-javadoc.noarch : Javadoc for ldapjdkjava-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-accessibility.x86_64 : OpenJDK accessibility connectorjava-1.7.0-openjdk-demo.x86_64 : OpenJDK Demosjava-1.7.0-openjdk-devel.x86_64 : OpenJDK Development Environmentjava-1.7.0-openjdk-headless.x86_64 : The OpenJDK runtime environment withoutjava-1.7.0-openjdk-javadoc.noarch : OpenJDK API Documentationjava-1.7.0-openjdk-src.x86_64 : OpenJDK Source Bundlejava-1.8.0-openjdk.i686 : OpenJDK Runtime Environmentjava-1.8.0-openjdk.x86_64 : OpenJDK Runtime Environmentjava-1.8.0-openjdk-accessibility.x86_64 : OpenJDK accessibility connectorjava-1.8.0-openjdk-accessibility-debug.x86_64 : OpenJDK accessibility connectorjava-1.8.0-openjdk-debug.i686 : OpenJDK Runtime Environment with full debug onjava-1.8.0-openjdk-debug.x86_64 : OpenJDK Runtime Environment with full debug onjava-1.8.0-openjdk-demo.x86_64 : OpenJDK Demosjava-1.8.0-openjdk-demo-debug.x86_64 : OpenJDK Demos with full debug onjava-1.8.0-openjdk-devel.i686 : OpenJDK Development Environmentjava-1.8.0-openjdk-devel.x86_64 : OpenJDK Development Environmentjava-1.8.0-openjdk-devel-debug.i686 : OpenJDK Development Environment with fulljava-1.8.0-openjdk-devel-debug.x86_64 : OpenJDK Development Environment withjava-1.8.0-openjdk-headless.i686 : OpenJDK Runtime Environmentjava-1.8.0-openjdk-headless.x86_64 : OpenJDK Runtime Environmentjava-1.8.0-openjdk-headless-debug.i686 : OpenJDK Runtime Environment with fulljava-1.8.0-openjdk-headless-debug.x86_64 : OpenJDK Runtime Environment with fulljava-1.8.0-openjdk-javadoc.noarch : OpenJDK API Documentationjava-1.8.0-openjdk-javadoc-debug.noarch : OpenJDK API Documentation for packagesjava-1.8.0-openjdk-javadoc-zip.noarch : OpenJDK API Documentation compressed injava-1.8.0-openjdk-javadoc-zip-debug.noarch : OpenJDK API Documentationjava-1.8.0-openjdk-src.x86_64 : OpenJDK Source Bundlejava-1.8.0-openjdk-src-debug.x86_64 : OpenJDK Source Bundle for packages withldapjdk.noarch : The Mozilla LDAP Java SDK

选择版本进行安装

注意不要选择最新的版本

 yum install java-1.7.0-openjdk 

设置环境变量

vi /etc/profile 

直接复制粘贴下面的配置：

#set java environment JAVA_HOME=/usr/lib/jvm/java-1.7.0-openjdk-1.7.0.75.x86_64 JRE_HOME=$JAVA_HOME/jre CLASS_PATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar:$JRE_HOME/lib PATH=$PATH:$JAVA_HOME/bin:$JRE_HOME/bin export JAVA_HOME JRE_HOME CLASS_PATH PATH 

让修改生效

source /etc/profile 

检查安装是否成功

java -version