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社区首页 >问答首页 >Java ImageIO: OSGI兼容的ClassNotFoundException中的第一次调用

问Java ImageIO: OSGI兼容的ClassNotFoundException中的第一次调用
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Stack Overflow用户
提问于 2020-06-16 22:42:46
回答 2查看 146关注 0票数 0

我正在为Protege应用程序开发一个本体显示插件，这是符合OSGI的。我继承的图形库是Prefuse，它不兼容OSGI，并调用ImageIO来保存显示的图像。我已经看到在OSGI框架之外调用初始化问题，但是我尝试过的任何东西都解决不了ImageIO抛出的ImageIO，而且我也无法捕捉到异常。

IntelliJ是Java，Java是Java8。

是否有一些初始化可以从OSGI框架中“找到”ImageIO库？

下面是抛出错误的代码：

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public class SaveDisplayAction extends AbstractAction {

    private Display display;
    private JFileChooser chooser;
    private ScaleSelector scaler;
    private BufferedImage bufferedImage;

    /**
     * Create a new SaveDisplayAction for the given Display.
     * @param display the Display to capture
     */
    public SaveDisplayAction(Display display) {
        this.display = display;
    }

    private void init() {
        boolean useCache = ImageIO.getUseCache(); //     **<-- throws ClassDefNotFoundException**
    }


    /**
     * Shows the image export dialog and processes the results.
     * @see java.awt.event.ActionListener#actionPerformed(java.awt.event.ActionEvent)
     */
    public void actionPerformed(ActionEvent evt) {
        // lazy initialization
        if ( chooser == null )
            init();
    }
}

下面是抛出的异常。应用程序继续进行，但是对ImageIO库的任何进一步调用都会引发类似的异常。

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17:17:41.377 [AWT-EventQueue-0] ERROR o.p.editor.core.ProtegeApplication - Uncaught Exception in thread 'AWT-EventQueue-0'
java.lang.NoClassDefFoundError: javax/imageio/ImageIO
    at org.visualdataweb.vowl.controlView.SaveDisplayAction.init(SaveDisplayAction.java:54) ~[classes/:na]
    at org.visualdataweb.vowl.controlView.SaveDisplayAction.actionPerformed(SaveDisplayAction.java:119) ~[classes/:na]
    at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022) ~[na:1.8.0_231]
    at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2348) ~[na:1.8.0_231]
    at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402) ~[na:1.8.0_231]
    at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259) ~[na:1.8.0_231]
    at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252) ~[na:1.8.0_231]
    at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:289) ~[na:1.8.0_231]
    at java.awt.Component.processMouseEvent(Component.java:6539) ~[na:1.8.0_231]
    at javax.swing.JComponent.processMouseEvent(JComponent.java:3324) ~[na:1.8.0_231]
    at java.awt.Component.processEvent(Component.java:6304) ~[na:1.8.0_231]
    at java.awt.Container.processEvent(Container.java:2239) ~[na:1.8.0_231]
    at java.awt.Component.dispatchEventImpl(Component.java:4889) ~[na:1.8.0_231]
    at java.awt.Container.dispatchEventImpl(Container.java:2297) ~[na:1.8.0_231]
    at java.awt.Component.dispatchEvent(Component.java:4711) ~[na:1.8.0_231]
    at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4904) ~[na:1.8.0_231]
    at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4535) ~[na:1.8.0_231]
    at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4476) ~[na:1.8.0_231]
    at java.awt.Container.dispatchEventImpl(Container.java:2283) ~[na:1.8.0_231]
    at java.awt.Window.dispatchEventImpl(Window.java:2746) ~[na:1.8.0_231]
    at java.awt.Component.dispatchEvent(Component.java:4711) ~[na:1.8.0_231]
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:760) ~[na:1.8.0_231]
    at java.awt.EventQueue.access$500(EventQueue.java:97) ~[na:1.8.0_231]
    at java.awt.EventQueue$3.run(EventQueue.java:709) ~[na:1.8.0_231]
    at java.awt.EventQueue$3.run(EventQueue.java:703) ~[na:1.8.0_231]
    at java.security.AccessController.doPrivileged(Native Method) ~[na:1.8.0_231]
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:74) ~[na:1.8.0_231]
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:84) ~[na:1.8.0_231]
    at java.awt.EventQueue$4.run(EventQueue.java:733) ~[na:1.8.0_231]
    at java.awt.EventQueue$4.run(EventQueue.java:731) ~[na:1.8.0_231]
    at java.security.AccessController.doPrivileged(Native Method) ~[na:1.8.0_231]
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:74) ~[na:1.8.0_231]
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:730) ~[na:1.8.0_231]
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:205) [na:1.8.0_231]
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116) [na:1.8.0_231]
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105) [na:1.8.0_231]
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101) [na:1.8.0_231]
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93) [na:1.8.0_231]
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:82) [na:1.8.0_231]

Caused by: java.lang.ClassNotFoundException: javax.imageio.ImageIO not found by org.visualdataweb.boa.protege [20]
    at org.apache.felix.framework.BundleWiringImpl.findClassOrResourceByDelegation(BundleWiringImpl.java:1574) ~[org.apache.felix.main-5.4.0.jar:na]
    at org.apache.felix.framework.BundleWiringImpl.access$400(BundleWiringImpl.java:79) ~[org.apache.felix.main-5.4.0.jar:na]
    at org.apache.felix.framework.BundleWiringImpl$BundleClassLoader.loadClass(BundleWiringImpl.java:2018) ~[org.apache.felix.main-5.4.0.jar:na]
    at java.lang.ClassLoader.loadClass(ClassLoader.java:351) ~[na:1.8.0_231]
    ... 39 common frames omitted

在编译期间，我收到以下警告消息：

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Warning:osgi: [boa] Bundle-Activator org.protege.editor.core.plugin.DefaultPluginActivator is being imported into the bundle rather than being contained inside it. This is usually a bundle packaging error

如果我将javax.imageio添加到Maven导入部分，则插件在试图激活时失败。我想是因为javax.imageio不是一个符合OSGI的包吧？

代码语言：javascript
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09:55:00.817 [FelixStartLevel] ERROR o.p.o.framework.FrameworkSlf4jLogger - Error starting file:/C:/Users/kcason/Documents/IdeaProjects/HPM/Protege/Protege-5.5.0-beta-3/plugins/boa-1.1.0.jar
org.osgi.framework.BundleException: Unable to resolve org.visualdataweb.boa.protege [20](R 20.0): missing requirement [org.visualdataweb.boa.protege [20](R 20.0)] osgi.wiring.package; (osgi.wiring.package=javax.imageio.ImageIO) Unresolved requirements: [[org.visualdataweb.boa.protege [20](R 20.0)] osgi.wiring.package; (osgi.wiring.package=javax.imageio.ImageIO)]
    at org.apache.felix.framework.Felix.resolveBundleRevision(Felix.java:4111) ~[org.apache.felix.main-5.4.0.jar:na]
    at org.apache.felix.framework.Felix.startBundle(Felix.java:2117) ~[org.apache.felix.main-5.4.0.jar:na]
    at org.apache.felix.framework.Felix.setActiveStartLevel(Felix.java:1371) ~[org.apache.felix.main-5.4.0.jar:na]
    at org.apache.felix.framework.FrameworkStartLevelImpl.run(FrameworkStartLevelImpl.java:308) [org.apache.felix.main-5.4.0.jar:na]
    at java.lang.Thread.run(Thread.java:748) [na:1.8.0_231]
java
plugins
osgi
javax.imageio
protege
EN

回答 2

Stack Overflow用户

发布于 2020-06-17 08:15:03

包org.visualdataweb.boa.protege使用类ImageIO并遇到错误。这表明包javax.imageio不是由这个包导入的。如果已导入包，则在解析过程中会出现错误。但是，当加载第一个类时会得到错误，因此无法正确导入。

因为使用十亿工具几乎不可能做到这一点，所以我假设您使用PDE作为您的开发环境？在这种情况下，您应该将javax.imageio的导入添加到META-INF/MANIFEST.MF文件中。

如果这不是问题，你必须提供更多的信息。

通常，当您报告这样一个错误时，您使用的开发环境对于提供正确的支持是非常关键的。现在JVM版本也很关键，但是我可以在使用1.8的堆栈跟踪中看到它。

票数 1
EN

Stack Overflow用户

发布于 2020-06-17 15:31:06

我将javax.imageio.ImageIO添加到Maven导入部分，并收到上述所有错误。当我把它缩短为javax.imageio (正如彼得上面所建议的)时，它起了作用！

票数 0
EN
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：

https://stackoverflow.com/questions/62418680

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