什么添加图片 描述详细点

代码发不上来，是一个java小游戏，java窗口，想加一个背景图片，但是不知道怎么加，

swing 不懂 爱莫能助了

还是谢谢。

以下转自百度文库
们在进行图形用户界面编程时，为了做出一个漂亮、个性化的界面，那么界面的背景就必须考虑了。要想灵活使用背景，就一定要对frame的基本有一些了解，因为在java编程中没有直接设置背景的有关方法，了解一些基本知识后我们就可以随意设置背景了。
首先还是要了解框架JFrame中的层次结构。JFrame中的层次分布及相对关系是:最底层是：JRootPane；第二层是：JlayerPane；最上层就是ContentPane,也正是我们常说的内容面板。所以一般我们拖放的控件就是在ContentPane层上。
有了这些常识后我们就可以随意设计背景了。在这里笔者提供两种方法为一个frame设置一张背景图片。
方法一：
原理：我们把图片放置在第二层：JlayerPane容器上，然后让最上层的：ContentPane透明，这样就实现了背景的设置。（当然把图片放置最低层，让上面两层透明也是可以的）
具体步骤：
// 加载背景图片
ImageIcon bg = new ImageIcon("background.jpg");
// 把背景图片显示在一个标签里
JLabel label = new JLabel(bg);
//把标签的大小位置设置为图片刚好填充整个面
label.setBounds(0,0,bg.getIconWidth(),bg.getIconHeight());
//添加图片到frame的第二层
frame.getLayeredPane().add(label,newInteger(Integer.MIN_VALUE));
//获取frame的最上层面板为了设置其背景颜色（JPanel有设置透明的方法）
JPanel jp=(JPanel)frame.getContentPane();
jp.setOpaque(false);//设置透明
//测试用的JPanel
JPanel panel=new JPanel();
panel.setOpaque(false);//也要让他透明
panel.setLayout(null);//为了使用按钮的定位
JButton button=new JButton("OK");
button.setSize(100, 20);
button.setLocation(100, 50);
panel.add(button);
方法二：
原理：我们直接在最上层容器内重写paintComponent(Graphics g)方法在容器中画一张图片。（这种方法很直观，原理很简单）
具体步骤：
只需要在构造JPanel时重写paintComponent(Graphics g)就ok了。
class PanelTest extends JPanel{
ImageIcon background = new ImageIcon("background.jpg");//加载图片
Image im=Toolkit.getDefaultToolkit().getImage("background.jpg");
int h,w;
public void paintComponent(Graphics g) {
g.drawImage(im, 0, 0, null);
}
}
总结：只要了解了基本原理我们就可以更随意一点设计我们的风格了，我在这了抛砖引玉，希望对初学者有所帮助。

重写底层面板的 paintComponent 方法
或者干脆用一个 JLabel 做底层，setIcon 设个图片上去

各位遇到一个这个问题，拦截器是可以指定到对应的java 类的，但是还是报cannot found，帮忙看下，谢谢~~
HTTP状态 500 - 内部服务器错误
类型 异常报告
消息 Servlet[springMVC]的Servlet.init（）引发异常
描述 服务器遇到一个意外的情况，阻止它完成请求。
例外情况
javax.servlet.ServletException: Servlet[springMVC]的Servlet.init（）引发异常org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541)org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:690)org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:373)org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868)org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1589)org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)java.lang.Thread.run(Unknown Source)
根本原因。
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping#0': Initialization of bean failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.web.servlet.handler.MappedInterceptor#1': Cannot create inner bean 'com.bookshop.system.LoginInterceptor#0' of type [com.bookshop.system.LoginInterceptor] while setting constructor argument; nested exception is org.springframework.beans.factory.CannotLoadBeanClassException: Cannot find class [com.bookshop.system.LoginInterceptor] for bean with name 'com.bookshop.system.LoginInterceptor#0' defined in ServletContext resource [/WEB-INF/conf/mvc-context.xml]; nested exception is java.lang.ClassNotFoundException: com.bookshop.system.LoginInterceptororg.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:527)org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:294) org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:631)org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:588)org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:645)org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:508)org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:449)org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:133)javax.servlet.GenericServlet.init(GenericServlet.java:158)
根本原因。
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.web.servlet.handler.MappedInterceptor#1': Cannot create inner bean 'com.bookshop.system.LoginInterceptor#0' of type [com.bookshop.system.LoginInterceptor] while setting constructor argument; nested exception is org.springframework.beans.factory.CannotLoadBeanClassException: Cannot find class [com.bookshop.system.LoginInterceptor] for bean with name 'com.bookshop.system.LoginInterceptor#0' defined in ServletContext resource [/WEB-INF/conf/mvc-context.xml]; nested exception is java.lang.ClassNotFoundException: com.bookshop.system.LoginInterceptororg.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveInnerBean(BeanDefinitionValueResolver.java:281)org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:120)org.springframework.beans.factory.support.ConstructorResolver.resolveConstructorArguments(ConstructorResolver.java:616)org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:148) org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeansOfType(DefaultListableBeanFactory.java:400)org.springframework.context.support.AbstractApplicationContext.getBeansOfType(AbstractApplicationContext.java:1164)org.springframework.beans.factory.BeanFactoryUtils.beansOfTypeIncludingAncestors(BeanFactoryUtils.java:275)org.springframework.web.servlet.handler.AbstractHandlerMapping.detectMappedInterceptors(AbstractHandlerMapping.java:212)org.springframework.web.servlet.handler.AbstractHandlerMapping.initApplicationContext(AbstractHandlerMapping.java:186)org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.initApplicationContext(AbstractHandlerMethodMapping.java:88)org.springframework.context.support.ApplicationObjectSupport.initApplicationContext(ApplicationObjectSupport.java:119)org.springframework.web.context.support.WebApplicationObjectSupport.initApplicationContext(WebApplicationObjectSupport.java:72)org.springframework.context.support.ApplicationObjectSupport.setApplicationContext(ApplicationObjectSupport.java:73)org.springframework.context.support.ApplicationContextAwareProcessor.invokeAwareInterfaces(ApplicationContextAwareProcessor.java:117)org.springframework.context.support.ApplicationContextAwareProcessor.postProcessBeforeInitialization(ApplicationContextAwareProcessor.java:92)org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsBeforeInitialization(AbstractAutowireCapableBeanFactory.java:394)org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1448)org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:519)org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:294)org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:225)org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:291)org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:585)org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:913)org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:464)
java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)java.lang.Thread.run(Unknown Source)
根本原因。
org.springframework.beans.factory.CannotLoadBeanClassException: Cannot find class [com.bookshop.system.LoginInterceptor] for bean with name 'com.bookshop.system.LoginInterceptor#0' defined in ServletContext resource [/WEB-INF/conf/mvc-context.xml]; nested exception is java.lang.ClassNotFoundException: com.bookshop.system.LoginInterceptororg.springframework.beans.factory.support.AbstractBeanFactory.resolveBeanClass(AbstractBeanFactory.java:1262) org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:508) org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868)org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1589)org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)java.lang.Thread.run(Unknown Source)
根本原因。
java.lang.ClassNotFoundException: com.bookshop.system.LoginInterceptororg.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1365)org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1188)org.springframework.util.ClassUtils.forName(ClassUtils.java:258)org.springframework.beans.factory.support.AbstractBeanDefinition.resolveBeanClass(AbstractBeanDefinition.java:417)org.springframework.beans.factory.support.AbstractBeanFactory.doResolveBeanClass(AbstractBeanFactory.java:1283)org.springframework.beans.factory.support.AbstractBeanFactory.resolveBeanClass(AbstractBeanFactory.java:1254) java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)java.lang.Thread.run(Unknown Source)
):注意 主要问题的全部 stack 信息可以在 server logs 里查看
Apache Tomcat/9.0.37