启动oracle时报错：PuTTY X11 proxy: unable to connect to forwarded X server: Network error:

在启动oracle时报如下错误是因为没有启动Xming，确保Xming启动之后再启动oracle即可。

[oracle@localhost ~]$ cd /data/oracle/product/19.3/db_1/bin
[oracle@localhost bin]$
[oracle@localhost bin]$
[oracle@localhost bin]$ ./dbca
PuTTY X11 proxy: unable to connect to forwarded X server: Network error: Connection refused
Exception in thread "main" java.lang.NoClassDefFoundError: Could not initialize class sun.awt.X11.XToolkit
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Class.java:264)
        at java.awt.Toolkit$2.run(Toolkit.java:860)
        at java.awt.Toolkit$2.run(Toolkit.java:855)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.awt.Toolkit.getDefaultToolkit(Toolkit.java:854)
        at com.jgoodies.looks.LookUtils.isLowResolution(LookUtils.java:484)
        at com.jgoodies.looks.LookUtils.<clinit>(LookUtils.java:249)
        at com.jgoodies.looks.plastic.PlasticLookAndFeel.<clinit>(PlasticLookAndFeel.java:135)
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Class.java:348)
        at javax.swing.SwingUtilities.loadSystemClass(SwingUtilities.java:1879)
        at javax.swing.UIManager.setLookAndFeel(UIManager.java:582)
        at oracle.install.commons.util.Application.startup(Application.java:976)
        at oracle.install.commons.flow.FlowApplication.startup(FlowApplication.java:181)
        at oracle.install.commons.flow.FlowApplication.startup(FlowApplication.java:198)
        at oracle.assistants.common.base.driver.AssistantApplication.startup(AssistantApplication.java:336)
        at oracle.assistants.dbca.driver.DBConfigurator.startup(DBConfigurator.java:378)
        at oracle.assistants.dbca.driver.DBConfigurator.main(DBConfigurator.java:513)