在Joget应用程序的“ 流程”选项卡中，在某些情况下（例如进程图更新），将会生成和更新进程的映像。在某些情况下可能无法生成图像。
下面的信息会长时间保持不变，否则如果生成失败，您可能会得到空白的图像。
图1：进程缩略图没有被生成
可能的问题1 - 在主文件夹上的权限访问
您可能需要对 /wflow主文件夹授予足够的读/写权限。
使用具有访问该文件夹权限的相同用户启动您的Joget服务器。
可能的问题2
In the Processes tab of your Joget app, images of your processes will be generated and updated under certain circumstances (e.g. process diagram update). The images may not get generated under certain circumstances.
The message below will stay the same for a prolonged period or you may get a blank image if the generation fails.
Figure 1: Process thumbnail not being generated
Possible problem 1 - Permission access on home folder
You may need to grant sufficient read/write permission to the /wflow home folder.
Start up your Joget server using the same user with the permission to access the folder.
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- java.awt.
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headless错误
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Caused by: java.awt.HeadlessException: No X11 DISPLAY variable was set, but this program performed an operation which requires it. at java.awt.GraphicsEnvironment.checkHeadless(GraphicsEnvironment.java:207) |
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Caused by: java.awt.HeadlessException: No X11 DISPLAY variable was set, but this program performed an operation which requires it. at java.awt.GraphicsEnvironment.checkHeadless(GraphicsEnvironment.java:159) at java.awt.Window.<init>(Window.java:433) at java.awt.Frame.<init>(Frame.java:403) at java.awt.Frame.<init>(Frame.java:368) at javax.swing.SwingUtilities$SharedOwnerFrame.<init>(SwingUtilities.java:1733) at javax.swing.SwingUtilities.getSharedOwnerFrame(SwingUtilities.java:1810) at javax.swing.JDialog.<init>(JDialog.java:253) at javax.swing.JDialog.<init>(JDialog.java:187) at javax.swing.JDialog.<init>(JDialog.java:160) |
The server that hosts Joget may not have full graphic support, therefore, you can try to run the server in headless mode by adding the following parameter to the startup script (i.e. tomcat6.sh) under JAVA_OPTS.承载Joget的服务器可能没有完整的图形支持，因此，您可以尝试通过将以下参数添加到JAVA_OPTS下的启动脚本（即tomcat6.sh）中来以无头模式运行服务器。
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-Djava.awt.headless=true |
More references:更多参考：
http://stackoverflow.com/questions/5576986/servlet-giving-error-java-lang-noclassdeffounderror
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http://dev.joget.org/community/pages/viewpage.action?pageId=12976186
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可能的问题3 -
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域名/ DNS /
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路由问题
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ERROR 04 Nov 2014 22:47:22 org.joget.workflow.util.XpdlImageUtil - Error generating xpdl image [processDefId=ABC#7#WPIApplication] java.net.ConnectException: Connection refused: connect |
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当正在生成进程缩略图时，将会进行http调用。
您将需要确保您能够从托管Joget本身的服务器ping /调用域本身。（例如，您的域名是gojoget.com -
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您的服务器必须能够ping到gojoget.com）
如果您遇到类似的问题，请尝试修改您的主机文件，以便重定向到本地主机。
as well)If you are facing similar issue such as this, try to modify your host file so that it would redirect to your localhost.
Example:-
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# ip<space>domain 201.225.100.01 localhost |
Possible problem 4 - Outdated cached process images
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可能的问题4 - 过期的缓存过程映像
如果你已经尝试了上述解决方案，仍然无法正常工作，那么你可以尝试清除Joget主文件夹中的缓存图像（通常位于[USER]/wflow/app_xpdlImages）刷新浏览器页面，以便它会尝试再次生成新的缩略图
) Refresh your browser page so that it will attempt to generate new thumbnails again.