我不斷收到錯誤「InstantiationException」當我試圖從我的自定義解串器運行,下面這段代碼:爪哇 - 強制實例化的
String attr = nel.getAttribute("class");
//happens when attr = "java.awt.Color"
if (attr != null && !attr.isEmpty()){
Object no = Class.forName(attr).newInstance(); <--- dies here
readObject(nel, no, true);
field.set(obj, no);
}
奇怪的是,它的工作在一個點,現在它不「T。
我該如何強制newInstance,然後設置該對象中的字段(readObject是否是我自己的函數)?
下面是一些調試信息:
java.lang.InstantiationException: java.awt.Color
at java.lang.Class.newInstance0(Class.java:357)
at java.lang.Class.newInstance(Class.java:325)
at wms.lsw.tool.CustomXMLDecoder.readObject(CustomXMLDecoder.java:240)
at wms.lsw.tool.CustomXMLDecoder.decode(CustomXMLDecoder.java:92)
at wms.lsw.tool.Utils.openProject(Utils.java:716)
at wms.lsw.tool.SecondaryMenuBar$2.actionPerformed(SecondaryMenuBar.java:52)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:289)
at java.awt.Component.processMouseEvent(Component.java:6505)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
at java.awt.Component.processEvent(Component.java:6270)
at java.awt.Container.processEvent(Container.java:2229)
at java.awt.Component.dispatchEventImpl(Component.java:4861)
at java.awt.Container.dispatchEventImpl(Container.java:2287)
at java.awt.Component.dispatchEvent(Component.java:4687)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
at java.awt.Container.dispatchEventImpl(Container.java:2273)
at java.awt.Window.dispatchEventImpl(Window.java:2719)
at java.awt.Component.dispatchEvent(Component.java:4687)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:723)
at java.awt.EventQueue.access$200(EventQueue.java:103)
at java.awt.EventQueue$3.run(EventQueue.java:682)
at java.awt.EventQueue$3.run(EventQueue.java:680)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
at java.awt.EventQueue$4.run(EventQueue.java:696)
at java.awt.EventQueue$4.run(EventQueue.java:694)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:693)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:244)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:163)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:147)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:139)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:97)
更新1
好,因爲類顏色需要aruguments,我該怎麼傳遞默認的東西一類,如果一類自動需要aruguments?或者有可能注入一個默認的構造函數?
謝謝。
什麼是完整的堆棧跟蹤? 'attr'導致異常的價值是什麼? – reprogrammer
要實例化的類要麼沒有默認的構造函數,要麼是抽象的。你不能「強制」實例化一個無法實例化的類。 – Vulcan
你是否控制你正在實例化的類? – ruakh