linux安装oracle数据库时出现 No protocol specified

>>> Ignoring required pre-requisite failures. Continuing...
Preparing to launch Oracle Universal Installer from /tmp/OraInstall2017-08-01_01-21-52AM. Please wait ...[oracle@localhost database]$ No protocol specified
Exception in thread "main" java.lang.NoClassDefFoundError
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:164)
at java.awt.Toolkit$2.run(Toolkit.java:821)
at java.security.AccessController.doPrivileged(Native Method)
at java.awt.Toolkit.getDefaultToolkit(Toolkit.java:804)
at com.jgoodies.looks.LookUtils.isLowResolution(Unknown Source)
at com.jgoodies.looks.LookUtils.(Unknown Source)
at com.jgoodies.looks.plastic.PlasticLookAndFeel.(PlasticLookAndFeel.java:122)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:242)
at javax.swing.SwingUtilities.loadSystemClass(SwingUtilities.java:1783)
at javax.swing.UIManager.setLookAndFeel(UIManager.java:480)
at oracle.install.commons.util.Application.startup(Application.java:758)
at oracle.install.commons.flow.FlowApplication.startup(FlowApplication.java:164)
at oracle.install.commons.flow.FlowApplication.startup(FlowApplication.java:181)
at oracle.install.commons.base.driver.common.Installer.startup(Installer.java:265)
at oracle.install.ivw.db.driver.DBInstaller.startup(DBInstaller.java:114)

at oracle.install.ivw.db.driver.DBInstaller.main(DBInstaller.java:132)

解决方法是，在linux界面切换成oracle用户登陆，即可。