先前系統上有JDK 6的安裝，由于要部署Facebook的Presto做一些測試，需要將其升級到JDK 7，但是在安裝的過程中遇到以下的問題：

[root@x01 data2]# rpm -ivh --force --replacepkgs jdk-7u45-linux-x64.rpm Preparing... ########################################### [100%]1:jdk ########################################### [100%] Unpacking JAR files...rt.jar... Error: Could not open input file: /usr/java/jdk1.7.0_45/jre/lib/rt.pack Error: unpack could not create JAR file:/usr/java/jdk1.7.0_45/jre/lib/rt.jarPlease refer to the Troubleshooting section of the Installation Instructions on the download page.jsse.jar... Error: Could not open input file: /usr/java/jdk1.7.0_45/jre/lib/jsse.pack Error: unpack could not create JAR file:/usr/java/jdk1.7.0_45/jre/lib/jsse.jarPlease refer to the Troubleshooting section of the Installation Instructions on the download page.charsets.jar... Error: Could not open input file: /usr/java/jdk1.7.0_45/jre/lib/charsets.pack Error: unpack could not create JAR file:/usr/java/jdk1.7.0_45/jre/lib/charsets.jarPlease refer to the Troubleshooting section of the Installation Instructions on the download page.tools.jar... Error: Could not open input file: /usr/java/jdk1.7.0_45/lib/tools.pack Error: unpack could not create JAR file:/usr/java/jdk1.7.0_45/lib/tools.jarPlease refer to the Troubleshooting section of the Installation Instructions on the download page.localedata.jar... Error: Could not open input file: /usr/java/jdk1.7.0_45/jre/lib/ext/localedata.pack Error: unpack could not create JAR file:/usr/java/jdk1.7.0_45/jre/lib/ext/localedata.jarPlease refer to the Troubleshooting section of the Installation Instructions on the download page.jfxrt.jar... Error: Could not open input file: /usr/java/jdk1.7.0_45/jre/lib/jfxrt.pack Error: unpack could not create JAR file:/usr/java/jdk1.7.0_45/jre/lib/jfxrt.jarPlease refer to the Troubleshooting section of the Installation Instructions on the download page.
如果在這種情況下，我們查看Java的版本，會報出以下的錯誤：

[root@x01 data2]# java -version Error occurred during initialization of VM java/lang/NoClassDefFoundError: java/lang/Object
最終的解決辦法，是清理掉系統殘留的舊版本的相關的安裝：

[root@x01 data2]# rpm -qa | grep jdk jdk-1.7.0_45-fcs.x86_64 [root@x01 data2]# rpm -e jdk-1.7.0_45-fcs.x86_64 [root@x01 data2]# rpm -qa | grep jdk [root@x01 data2]# rpm -qa | grep java sun-javadb-core-10.6.2-1.1.i386 sun-javadb-javadoc-10.6.2-1.1.i386 sun-javadb-common-10.6.2-1.1.i386 sun-javadb-client-10.6.2-1.1.i386 sun-javadb-docs-10.6.2-1.1.i386 sun-javadb-demo-10.6.2-1.1.i386 [root@x01 data2]# rpm -e sun-javadb-* error: package sun-javadb-* is not installed [root@x01 data2]# rpm -e sun-javadb-core-10.6.2-1.1.i386 sun-javadb-javadoc-10.6.2-1.1.i386 sun-javadb-common-10.6.2-1.1.i386 sun-javadb-client-10.6.2-1.1.i386 sun-javadb-docs-10.6.2-1.1.i386 sun-javadb-demo-10.6.2-1.1.i386 [root@x01 data2]# rpm -qa | grep java [root@x01 data2]# rpm -qa | grep jre [root@x01 data2]# rpm -qa | grep java [root@x01 data2]# rpm -qa | grep jdk
這樣之后，再運行先前的安裝程序即可：

[root@x01 data2]# rpm -ivh jdk-7u45-linux-x64.rpm Preparing... ########################################### [100%]1:jdk ########################################### [100%] Unpacking JAR files...rt.jar...jsse.jar...charsets.jar...tools.jar...localedata.jar...jfxrt.jar... [root@x01 data2]# source /etc/profile [root@x01 data2]# java -version java version "1.7.0_45" Java(TM) SE Runtime Environment (build 1.7.0_45-b18) Java HotSpot(TM) 64-Bit Server VM (build 24.45-b08, mixed mode) [root@x01 data2]#
Done!

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