Sun Java认证题库:核心知识点与考试指南

需积分: 13 4 下载量 53 浏览量 更新于2024-07-23 收藏 226KB PDF 举报
Sun Java程序员认证考试题库包含了丰富的题目,旨在考察考生对Java编程语言及其相关技术的掌握程度。这份题库分为几个部分,每个部分涉及不同的主题。 1-1部分主要涉及基础概念,包括字符集、标识符、Java关键字等。这部分涵盖了Java的基本语法和符号系统,如变量声明、控制流语句(`Go`、`Swing`、`JDK`、`JRE`和`JVM`等),以及与GUI(图形用户界面)开发相关的知识点。题目展示了Java编译器(`javac`)、调试工具(`jdb`)、文档生成(`javadoc`)和单元测试框架(`JUnit4`)等工具的使用。 1-2部分深入到Java编程的API和框架层面,比如`Java API`、`Java EE`、`JDK`、`JRE`、`JVM`之间的关系,以及使用特定命令行工具如`javadoc`进行API文档生成。题目还涉及了不同类型的Java应用程序,例如Java应用程序运行环境(`JVM`执行Java字节码)、命令行工具`java`的不同用途(例如`javac`编译源代码、`junit`进行单元测试)。 1-3和后续部分则着重于更具体的技术细节,如使用XML(`XMLḐᓣ`)、网络通信(`Պɵ`)和HTML(`HTMLḐᓣ`)与Java的交互,以及Java虚拟机(JVM)在运行时环境中的作用。这些题目要求考生理解如何在各种平台上(如Solaris和Windows)部署Java应用,并利用JVM的特性进行程序执行和调试。 8和9的问题涉及到Applet的开发,这是Java早期的一种应用程序模型,运行在浏览器中。考生需要了解如何编写Applet,以及与Java字节码处理(`Java⿟ᑣ`)和跨平台兼容性(`䯈݇㋏`)相关的知识点。 这份题库全面覆盖了Java程序员认证考试所需的核心知识点,包括语言基础、框架、API、工具使用和平台兼容性等内容,对于备考者来说是一份宝贵的参考资料。

Exception in Application constructor Exception in thread "main" java.lang.reflect.InvocationTargetException at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:568) at java.base/sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:1071) Caused by: java.lang.RuntimeException: Unable to construct Application instance: class com.example.demo.Main at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:891) at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication$2(LauncherImpl.java:196) at java.base/java.lang.Thread.run(Thread.java:833) Caused by: java.lang.IllegalAccessException: class com.sun.javafx.application.LauncherImpl (in module javafx.graphics) cannot access class com.example.demo.Main (in module com.example.javafxtest) because module com.example.javafxtest does not export com.example.demo to module javafx.graphics at java.base/jdk.internal.reflect.Reflection.newIllegalAccessException(Reflection.java:392) at java.base/java.lang.reflect.AccessibleObject.checkAccess(AccessibleObject.java:674) at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:489) at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:480) at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$8(LauncherImpl.java:803) at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runAndWait$12(PlatformImpl.java:484) at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$10(PlatformImpl.java:457) at java.base/java.security.AccessController.doPrivileged(AccessController.java:399) at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$11(PlatformImpl.java:456) at javafx.graphics/com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:96) at javafx.graphics/com.sun.glass.ui.win.WinApplication._runLoop(Native Method) at javafx.graphics/com.sun.glass.ui.win.WinApplication.lambda$runLoop$3(WinApplication.java:184) ... 1 more

2023-05-24 上传

idea报错org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/platform]] at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154) at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:901) at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:877) at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:632) at org.apache.catalina.startup.HostConfig.manageApp(HostConfig.java:1740) 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.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:301) at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819) at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801) at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:618) at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:565) 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.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:301) at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819) at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801) at com.sun.jmx.remote.security.MBeanServerAccessController.invoke(MBeanServerAccessController.java:468) at javax.management.remote.rmi.RMIConnectionImpl.doOperation(RMIConnectionImpl.java:1487) at javax.management.remote.rmi.RMIConnectionImpl.access$300(RMIConnectionImpl.java:97) at javax.management.remote.rmi.RMIConnectionImpl$PrivilegedOperation.run(RMIConnectionImpl.java:1328) at java.security.AccessController.doPrivileged(Native Method) at javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(RMIConnectionImpl.java:1427) at javax.management.remote.rmi.RMIConnectionImpl.invoke(RMIConnectionImpl.java:848) 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 sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:322) at sun.rmi.transport.Transport$2.run(Transport.java:202) at sun.rmi.transport.Transport$2.run(Transport.java:199) at java.security.AccessController.doPrivileged(Native Method) at sun.rmi.transport.Transport.serviceCall(Transport.java:198) at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:567) at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:828) at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.access$400(TCPTransport.java:619) at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler$1.run(TCPTransport.java:684) at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler$1.run(TCPTransport.java:681) at java.security.AccessController.doPrivileged(Native Method) at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:681) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) at java.lang.Thread.run(Thread.java:745) Caused by: java.lang.NoSuchFieldError: IS_SECURITY_ENABLED 如何解决

2023-07-14 上传