centos 7 java版本切换

2321212dd

有一个项目需要java 1.7配合，原服务器上已安装java 1.8，需要切换版本到java 1.7.

查看centos7支持的java版本

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27

yum search java|grep java-1 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-accessibility.x86_64 : OpenJDK accessibility connector 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-headless.x86_64 : The OpenJDK runtime environment without java-1.7.0-openjdk-javadoc.noarch : OpenJDK API Documentation java-1.7.0-openjdk-src.x86_64 : OpenJDK Source Bundle java-1.8.0-openjdk.x86_64 : OpenJDK Runtime Environment java-1.8.0-openjdk-accessibility.x86_64 : OpenJDK accessibility connector java-1.8.0-openjdk-accessibility-debug.x86_64 : OpenJDK accessibility connector java-1.8.0-openjdk-debug.x86_64 : OpenJDK Runtime Environment with full debug on java-1.8.0-openjdk-demo.x86_64 : OpenJDK Demos java-1.8.0-openjdk-demo-debug.x86_64 : OpenJDK Demos with full debug on java-1.8.0-openjdk-devel.x86_64 : OpenJDK Development Environment java-1.8.0-openjdk-devel-debug.x86_64 : OpenJDK Development Environment with java-1.8.0-openjdk-headless.x86_64 : OpenJDK Runtime Environment java-1.8.0-openjdk-headless-debug.x86_64 : OpenJDK Runtime Environment with full java-1.8.0-openjdk-javadoc.noarch : OpenJDK API Documentation java-1.8.0-openjdk-javadoc-debug.noarch : OpenJDK API Documentation for packages java-1.8.0-openjdk-src.x86_64 : OpenJDK Source Bundle java-1.8.0-openjdk-src-debug.x86_64 : OpenJDK Source Bundle for packages with

安装java 1.7版本

1	yum install java-1.7.0

使用update-alternatives 查看已安装的java版本

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

update-alternatives --list libnssckbi.so.x86_64    auto    /usr/lib64/pkcs11/p11-kit-trust.so ld      auto    /usr/bin/ld.bfd mkisofs auto    /usr/bin/genisoimage print   auto    /usr/bin/lpr.cups java    manual  /usr/lib/jvm/java-1.7.0-openjdk-1.7.0.111-2.6.7.2.el7_2.x86_64/jre/bin/java jre_openjdk     auto    /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.111-1.b15.el7_2.x86_64/jre jre_1.8.0       auto    /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.111-1.b15.el7_2.x86_64/jre jre_1.8.0_openjdk       auto    /usr/lib/jvm/jre-1.8.0-openjdk-1.8.0.111-1.b15.el7_2.x86_64 xinputrc        auto    /etc/X11/xinit/xinput.d/ibus.conf libjavaplugin.so.x86_64 auto    /usr/lib64/IcedTeaPlugin.so cifs-idmap-plugin       auto    /usr/lib64/cifs-utils/cifs_idmap_sss.so mta     auto    /usr/sbin/sendmail.postfix cdrecord        auto    /usr/bin/wodim libwbclient.so.0.12-64  auto    /usr/lib64/samba/wbclient/libwbclient.so.0.12 jre_1.7.0       auto    /usr/lib/jvm/java-1.7.0-openjdk-1.7.0.111-2.6.7.2.el7_2.x86_64/jre jre_1.7.0_openjdk       auto    /usr/lib/jvm/jre-1.7.0-openjdk-1.7.0.111-2.6.7.2.el7_2.x86_64

看到java1.7已安装成功，切换版本到java 1.7

1 2 3 4 5 6 7

update-alternatives --config java There are 2 programs which provide 'java'.   Selection    Command ----------------------------------------------- *  1           /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.111-1.b15.el7_2.x86_64/jre/bin/java + 2           /usr/lib/jvm/java-1.7.0-openjdk-1.7.0.111-2.6.7.2.el7_2.x86_64/jre/bin/java Enter to keep the current selection[+], or type selection number: 2

查看正在使用的java版本

1 2 3 4

java -version java version "1.7.0_111" OpenJDK Runtime Environment (rhel-2.6.7.2.el7_2-x86_64 u111-b01) OpenJDK 64-Bit Server VM (build 24.111-b01, mixed mode)

已成功切换到java 1.7版本。