ClassNotFoundException:服务器
ClassNotFoundException: Server
我遇到了标题中提到的问题。我想做的是编译我的服务器 class 并在我的主 class 是 运行 时执行它。
这是我的主程序中的 runServer 方法 class
public static void runServer() throws Exception{
File sourceFile = new File("/Users/Joel/NetbeansProjects/FYP/src/ui_v2/Server.java");
JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
StandardJavaFileManager fileMgr = compiler.getStandardFileManager(null, null, null);
fileMgr.setLocation(StandardLocation.CLASS_OUTPUT, Arrays.asList(new File("/Users/Joel/NetbeansProjects/FYP/src/ui_v2")));
compiler.getTask(null, fileMgr, null, null, null,
fileMgr.getJavaFileObjectsFromFiles(Arrays.asList(sourceFile)));
fileMgr.close();
try {
Class params[] = {};
Object paramsObj[] = {};
Class thisClass = Class.forName("Server");
Method thisMethod = thisClass.getMethod("main", params);
thisMethod.invoke(thisClass, paramsObj);
}
catch (Exception e) {
e.printStackTrace();
}
}
这是我的 ui_v2
文件夹中文件的屏幕截图。
这是我的错误:
java.lang.ClassNotFoundException: Server
at java.net.URLClassLoader.run(URLClassLoader.java:372)
at java.net.URLClassLoader.run(URLClassLoader.java:361)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:360)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:260)
at ui_v2.GenerateChat.runServer(GenerateChat.java:353)
at ui_v2.GenerateChat.Btn_ConfirmActionPerformed(GenerateChat.java:230)
at ui_v2.GenerateChat.access[=11=]0(GenerateChat.java:26)
at ui_v2.GenerateChat.actionPerformed(GenerateChat.java:129)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2346)
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.Component.processMouseEvent(Component.java:6525)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
at java.awt.Component.processEvent(Component.java:6290)
at java.awt.Container.processEvent(Container.java:2234)
at java.awt.Component.dispatchEventImpl(Component.java:4881)
at java.awt.Container.dispatchEventImpl(Container.java:2292)
at java.awt.Component.dispatchEvent(Component.java:4703)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4898)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4533)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4462)
at java.awt.Container.dispatchEventImpl(Container.java:2278)
at java.awt.Window.dispatchEventImpl(Window.java:2739)
at java.awt.Component.dispatchEvent(Component.java:4703)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:746)
at java.awt.EventQueue.access0(EventQueue.java:97)
at java.awt.EventQueue.run(EventQueue.java:697)
at java.awt.EventQueue.run(EventQueue.java:691)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain.doIntersectionPrivilege(ProtectionDomain.java:75)
at java.security.ProtectionDomain.doIntersectionPrivilege(ProtectionDomain.java:86)
at java.awt.EventQueue.run(EventQueue.java:719)
at java.awt.EventQueue.run(EventQueue.java:717)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain.doIntersectionPrivilege(ProtectionDomain.java:75)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:716)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)
如您所见,上述Server.class在sourceFile
中文件路径中所写的文件夹中。所以我不知道我当前的代码有什么问题,而是给我一个例外。
with Class.forName("Server")
您的类路径应设置为 ui_v2 文件夹,否则您需要提供包含包的名称,直到设置类路径。说你的类路径设置为 src 你需要给路径
Class.forName("ui_v2.Server")
更新:- main 方法也没有以正确的方式调用。应该是
Method thisMethod = thisClass.getMethod("main", String[].class);
thisMethod .invoke(null, params);// static method doesn't have an instance
如果你不想传递任何参数,你可以将参数作为 null 传递
我遇到了标题中提到的问题。我想做的是编译我的服务器 class 并在我的主 class 是 运行 时执行它。
这是我的主程序中的 runServer 方法 class
public static void runServer() throws Exception{
File sourceFile = new File("/Users/Joel/NetbeansProjects/FYP/src/ui_v2/Server.java");
JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
StandardJavaFileManager fileMgr = compiler.getStandardFileManager(null, null, null);
fileMgr.setLocation(StandardLocation.CLASS_OUTPUT, Arrays.asList(new File("/Users/Joel/NetbeansProjects/FYP/src/ui_v2")));
compiler.getTask(null, fileMgr, null, null, null,
fileMgr.getJavaFileObjectsFromFiles(Arrays.asList(sourceFile)));
fileMgr.close();
try {
Class params[] = {};
Object paramsObj[] = {};
Class thisClass = Class.forName("Server");
Method thisMethod = thisClass.getMethod("main", params);
thisMethod.invoke(thisClass, paramsObj);
}
catch (Exception e) {
e.printStackTrace();
}
}
这是我的 ui_v2
文件夹中文件的屏幕截图。
java.lang.ClassNotFoundException: Server
at java.net.URLClassLoader.run(URLClassLoader.java:372)
at java.net.URLClassLoader.run(URLClassLoader.java:361)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:360)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:260)
at ui_v2.GenerateChat.runServer(GenerateChat.java:353)
at ui_v2.GenerateChat.Btn_ConfirmActionPerformed(GenerateChat.java:230)
at ui_v2.GenerateChat.access[=11=]0(GenerateChat.java:26)
at ui_v2.GenerateChat.actionPerformed(GenerateChat.java:129)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2346)
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.Component.processMouseEvent(Component.java:6525)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
at java.awt.Component.processEvent(Component.java:6290)
at java.awt.Container.processEvent(Container.java:2234)
at java.awt.Component.dispatchEventImpl(Component.java:4881)
at java.awt.Container.dispatchEventImpl(Container.java:2292)
at java.awt.Component.dispatchEvent(Component.java:4703)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4898)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4533)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4462)
at java.awt.Container.dispatchEventImpl(Container.java:2278)
at java.awt.Window.dispatchEventImpl(Window.java:2739)
at java.awt.Component.dispatchEvent(Component.java:4703)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:746)
at java.awt.EventQueue.access0(EventQueue.java:97)
at java.awt.EventQueue.run(EventQueue.java:697)
at java.awt.EventQueue.run(EventQueue.java:691)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain.doIntersectionPrivilege(ProtectionDomain.java:75)
at java.security.ProtectionDomain.doIntersectionPrivilege(ProtectionDomain.java:86)
at java.awt.EventQueue.run(EventQueue.java:719)
at java.awt.EventQueue.run(EventQueue.java:717)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain.doIntersectionPrivilege(ProtectionDomain.java:75)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:716)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)
如您所见,上述Server.class在sourceFile
中文件路径中所写的文件夹中。所以我不知道我当前的代码有什么问题,而是给我一个例外。
with Class.forName("Server")
您的类路径应设置为 ui_v2 文件夹,否则您需要提供包含包的名称,直到设置类路径。说你的类路径设置为 src 你需要给路径
Class.forName("ui_v2.Server")
更新:- main 方法也没有以正确的方式调用。应该是
Method thisMethod = thisClass.getMethod("main", String[].class);
thisMethod .invoke(null, params);// static method doesn't have an instance
如果你不想传递任何参数,你可以将参数作为 null 传递