linux 下圖片上傳時報如下異常：
Caused by: 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:191)
at java.awt.Toolkit$2.run(Toolkit.java:869)
at java.security.AccessController.doPrivileged(Native Method)
at java.awt.Toolkit.getDefaultToolkit(Toolkit.java:861)
at java.awt.Image.getScaledInstance(Image.java:177)
at com.higreen.modules.app.utils.ImageUtils.scale(ImageUtils.java:51)
at com.higreen.modules.app.web.UploadPicController.uploadPic(UploadPicController.java:64)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:215)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:749)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:689)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:83)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:938)
... 41 more
解決方案：
找到tomcat下的bin/catalina.sh中JAVA_OPTS，在後面添加 -Djava.awt.headless=true即可。
