獲取圖像任務在Ant中工作

Question

我試圖在需要Java高級圖像的Ant中使用圖像任務。 .jar文件似乎是在Ant庫，但是當我嘗試縮放圖像，它給了我下面的錯誤：

Could not load a dependent class javax/media/jai/PlanarImage 

是否有一個原因，爲什麼螞蟻jai.jar文件不會已經有這個班了？有沒有人有在Ant中使用JAI或專門成功使用Image任務的經驗？

謝謝！

Answer 1

JAR僅包含Image task中定義的對象。你也必須把JAI放在你的班級路上。

附錄：關於NoClassDefFoundError: javax.media.jai.OperationRegistrySpi，您可以驗證該類是否在jai_core.jar中，如下所示。跟蹤這種異常情況的一種方法是使用java命令的-verbose選項。

 
$ jar tf jai_core.jar | grep OperationRegistrySpi 
javax/media/jai/OperationRegistrySpi.class 

$ jar tf lib/ant-jai.jar 
META-INF/ 
META-INF/MANIFEST.MF 
org/ 
org/apache/ 
org/apache/tools/ 
org/apache/tools/ant/ 
org/apache/tools/ant/taskdefs/ 
org/apache/tools/ant/taskdefs/optional/ 
org/apache/tools/ant/taskdefs/optional/image/ 
org/apache/tools/ant/taskdefs/optional/image/Image.class 
org/apache/tools/ant/types/ 
org/apache/tools/ant/types/optional/ 
org/apache/tools/ant/types/optional/image/ 
org/apache/tools/ant/types/optional/image/Arc.class 
org/apache/tools/ant/types/optional/image/BasicShape.class 
org/apache/tools/ant/types/optional/image/ColorMapper.class 
org/apache/tools/ant/types/optional/image/Draw.class 
org/apache/tools/ant/types/optional/image/DrawOperation.class 
org/apache/tools/ant/types/optional/image/Ellipse.class 
org/apache/tools/ant/types/optional/image/ImageOperation.class 
org/apache/tools/ant/types/optional/image/Rectangle.class 
org/apache/tools/ant/types/optional/image/Rotate.class 
org/apache/tools/ant/types/optional/image/Scale$ProportionsAttribute.class 
org/apache/tools/ant/types/optional/image/Scale.class 
org/apache/tools/ant/types/optional/image/Text.class 
org/apache/tools/ant/types/optional/image/TransformOperation.class