问题详细：
启动项目时，报错：
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'searchIPAttributionService' defined in file [***serviceSearchIPAttributionService.class]:
Instantiation of bean failed; nested exception is java.lang.ExceptionInInitializerError at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1013) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:959) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:490) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:461) at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:295) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:223) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:292) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194) at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:626) at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:932) at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:479) at org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:651) at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:599) at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:665) at org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:518) at org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:459) at org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:136) at javax.servlet.GenericServlet.init(GenericServlet.java:158) at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1284) at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1197) at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:1087) at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:5266) at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5554) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) 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:652) at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1263) at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:1948) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471) at java.util.concurrent.FutureTask.run(FutureTask.java:262) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) at java.lang.Thread.run(Thread.java:744) Caused by: java.lang.ExceptionInInitializerError at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:526) at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:148) at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:87) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1006) ... 33 more Caused by: java.lang.NullPointerException at ***.***.SearchIPAttributionService.load(SearchIPAttributionService.java:133) at ***.***.SearchIPAttributionService.load(SearchIPAttributionService.java:66) at ***.***.SearchIPAttributionService.<clinit>(SearchIPAttributionService.java:28) ... 40 more
解决过程：
1、检查配置，反反复复看了很多遍，确认没有问题。
2、 网上找了很多资料，类似的问题很多，看过答案以后依旧不得其要领。只好继续看报错代码，直到看到这一句：
Caused by: java.lang.NullPointerException at ***.***.SearchIPAttributionService.load(SearchIPAttributionService.java:133) at ***.***.SearchIPAttributionService.load(SearchIPAttributionService.java:66) at ***.***.SearchIPAttributionService.<clinit>(SearchIPAttributionService.java:28)
问题应该在本身的代码上，但是，我记得代码是测试过的，没有问题。但是，没有其他办法，只能顺着提示一步步寻找问题所在。最终，确实问题出在代码上。Spring在实例化这个类的时候，先执行静态方法，此时某个类还未实例化(检查是否已加注解)，故而报了这个空指针错误。
经验教训：
1、解决问题，不要急躁，要淡定，淡定，淡定。
2、仔细看报错信息。
3、每次修改过代码以后，都要记得进行测试，确保修改是正确的。