SpringBoot项目中遇到的异常

问题：

SpringBoot项目中集成了阿里开源Druid数据源，本地开发环境直接启动SpringBoot应用(SpringApplication.run方法)，启动成功，由于正式应用是部署在服务器已有的Tomcat环境中，经过改造将SpringBoot项目打成ROOT.war包后，部署到服务器上，启动应用程序时，报错了，错误信息如下所示：

15:13:34.616 repair [localhost-startStop-1] DEBUG o.springframework.jndi.JndiTemplate - Looking up JNDI object with name [java:comp/env/logging.level]
15:13:34.607 repair [localhost-startStop-1] DEBUG o.s.jndi.JndiPropertySource - JNDI lookup for name [logging.group] threw NamingException with message: Name [logging.group] is not bound in this Context. Unable to find [logging.group].. Returning null.
15:13:34.606 repair [localhost-startStop-1] DEBUG o.springframework.jndi.JndiTemplate - Looking up JNDI object with name [logging.group]
15:13:34.606 repair [localhost-startStop-1] DEBUG o.s.jndi.JndiLocatorDelegate - Converted JNDI name [java:comp/env/logging.group] not found - trying original name [logging.group]. javax.naming.NameNotFoundException: Name [logging.group] is not bound in this Context. Unable to find [logging.group].
15:13:34.580 repair [background-preinit] DEBUG o.h.v.m.ResourceBundleMessageInterpolator - Loaded expression factory via original TCCL
15:13:34.599 repair [localhost-startStop-1] DEBUG o.springframework.jndi.JndiTemplate - Looking up JNDI object with name [java:comp/env/logging.group]
15:13:34.578 repair [localhost-startStop-1] DEBUG o.s.jndi.JndiPropertySource - JNDI lookup for name [logging.group] threw NamingException with message: Name [logging.group] is not bound in this Context. Unable to find [logging.group].. Returning null.
15:13:34.577 repair [localhost-startStop-1] DEBUG o.springframework.jndi.JndiTemplate - Looking up JNDI object with name [logging.group]
15:13:34.577 repair [localhost-startStop-1] DEBUG o.s.jndi.JndiLocatorDelegate - Converted JNDI name [java:comp/env/logging.group] not found - trying original name [logging.group]. javax.naming.NameNotFoundException: Name [logging.group] is not bound in this Context. Unable to find [logging.group].
15:13:34.548 repair [localhost-startStop-1] DEBUG o.springframework.jndi.JndiTemplate - Looking up JNDI object with name [java:comp/env/logging.group]
    ... 74 common frames omitted
    at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.postProcessBeforeInitialization(InitDestroyAnnotationBeanPostProcessor.java:136)
    at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleMetadata.invokeInitMethods(InitDestroyAnnotationBeanPostProcessor.java:307)
    at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleElement.invoke(InitDestroyAnnotationBeanPostProcessor.java:363)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at cn.demo.repair.service.impl.VpServiceImpl.init(VpServiceImpl.java:42)
    at java.util.Properties.load(Properties.java:341)
    at java.util.Properties.load0(Properties.java:353)
    at java.util.Properties$LineReader.readLine(Properties.java:434)
Caused by: java.lang.NullPointerException: null
    ... 61 common frames omitted
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:593)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1166)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1239)
    at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:273)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
    at org.springframework.beans.factory.support.AbstractBeanFactory$$Lambda$120/684584821.getObject(Unknown Source)
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:498)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:576)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1737)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsBeforeInitialization(AbstractAutowireCapableBeanFactory.java:419)
    at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.postProcessBeforeInitialization(InitDestroyAnnotationBeanPostProcessor.java:139)
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'VpServiceImpl': Invocation of init method failed; nested exception is java.lang.NullPointerException
    ... 47 common frames omitted
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:593)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1166)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1239)
    at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:273)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
    at org.springframework.beans.factory.support.AbstractBeanFactory$$Lambda$120/684584821.getObject(Unknown Source)
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:498)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:575)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1378)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:374)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:90)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:596)
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'approvalServiceImpl': Unsatisfied dependency expressed through field 'vpService'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'VpServiceImpl': Invocation of init method failed; nested exception is java.lang.NullPointerException
    ... 33 common frames omitted
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:593)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1166)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1239)
    at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:273)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
    at org.springframework.beans.factory.support.AbstractBeanFactory$$Lambda$120/684584821.getObject(Unknown Source)
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:498)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:575)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1378)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:374)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:90)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:596)
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'repairServiceImpl': Unsatisfied dependency expressed through field 'approvalService'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'approvalServiceImpl': Unsatisfied dependency expressed through field 'vpService'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'VpServiceImpl': Invocation of init method failed; nested exception is java.lang.NullPointerException
    at java.lang.Thread.run(Thread.java:745)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
    at org.apache.catalina.startup.HostConfig$DeployWar.run(HostConfig.java:1823)
    at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:952)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:734)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:700)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:724)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5178)
    at org.springframework.web.SpringServletContainerInitializer.onStartup(SpringServletContainerInitializer.java:171)
    at org.springframework.boot.web.servlet.support.SpringBootServletInitializer.onStartup(SpringBootServletInitializer.java:91)
    at org.springframework.boot.web.servlet.support.SpringBootServletInitializer.createRootApplicationContext(SpringBootServletInitializer.java:137)
    at org.springframework.boot.web.servlet.support.SpringBootServletInitializer.run(SpringBootServletInitializer.java:157)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:316)
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397)
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:775)
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:140)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:546)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:863)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:846)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
    at org.springframework.beans.factory.support.AbstractBeanFactory$$Lambda$120/684584821.getObject(Unknown Source)
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:498)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:575)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1378)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:374)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:90)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:596)
org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'repairController': Unsatisfied dependency expressed through field 'repairService'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'repairServiceImpl': Unsatisfied dependency expressed through field 'approvalService'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'approvalServiceImpl': Unsatisfied dependency expressed through field 'vpService'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'VpServiceImpl': Invocation of init method failed; nested exception is java.lang.NullPointerException
15:07:53.610 repair [localhost-startStop-1] ERROR o.s.boot.SpringApplication - Application run failed
Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.

15:07:53.586 repair [localhost-startStop-1] INFO  o.s.b.a.l.ConditionEvaluationReportLoggingListener - 
15:07:53.536 repair [localhost-startStop-1] INFO  c.alibaba.druid.pool.DruidDataSource - {dataSource-1} closed
15:07:53.258 repair [localhost-startStop-1] WARN  o.s.b.w.s.c.AnnotationConfigServletWebServerApplicationContext - Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'repairController': Unsatisfied dependency expressed through field 'repairService'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'repairServiceImpl': Unsatisfied dependency expressed through field 'approvalService'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'approvalServiceImpl': Unsatisfied dependency expressed through field 'vpService'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'VpServiceImpl': Invocation of init method failed; nested exception is java.lang.NullPointerException
15:07:37.645 repair [localhost-startStop-1] INFO  c.alibaba.druid.pool.DruidDataSource - {dataSource-1} inited
15:07:28.073 repair [localhost-startStop-1] INFO  c.a.d.s.b.a.DruidDataSourceAutoConfigure - Init DruidDataSource
15:07:25.620 repair [localhost-startStop-1] INFO  o.s.b.w.s.FilterRegistrationBean - Mapping filter: 'webStatFilter' to urls: [/*]
15:07:25.619 repair [localhost-startStop-1] INFO  o.s.b.w.s.FilterRegistrationBean - Mapping filter: 'requestContextFilter' to: [/*]
15:07:25.619 repair [localhost-startStop-1] INFO  o.s.b.w.s.FilterRegistrationBean - Mapping filter: 'formContentFilter' to: [/*]
15:07:25.618 repair [localhost-startStop-1] INFO  o.s.b.w.s.FilterRegistrationBean - Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
15:07:25.618 repair [localhost-startStop-1] INFO  o.s.b.w.s.FilterRegistrationBean - Mapping filter: 'errorPageFilter' to: [/*]
15:07:25.617 repair [localhost-startStop-1] INFO  o.s.b.w.s.FilterRegistrationBean - Mapping filter: 'characterEncodingFilter' to: [/*]
15:07:25.570 repair [localhost-startStop-1] INFO  o.s.b.w.s.ServletRegistrationBean - Servlet statViewServlet mapped to [/druid/*]
15:07:25.568 repair [localhost-startStop-1] INFO  o.s.b.w.s.ServletRegistrationBean - Servlet dispatcherServlet mapped to [/]
15:07:23.151 repair [localhost-startStop-1] INFO  o.s.web.context.ContextLoader - Root WebApplicationContext: initialization completed in 16648 ms
15:07:22.043 repair [localhost-startStop-1] INFO  o.s.c.s.PostProcessorRegistrationDelegate$BeanPostProcessorChecker - Bean 'org.springframework.transaction.annotation.ProxyTransactionManagementConfiguration' of type [org.springframework.transaction.annotation.ProxyTransactionManagementConfiguration$$EnhancerBySpringCGLIB$$e7ee3861] is not eligible for getting processed by all BeanPostProcessors (for example: not eligible for auto-proxying)
15:07:17.690 repair [localhost-startStop-1] INFO  o.s.d.r.c.RepositoryConfigurationDelegate - Finished Spring Data repository scanning in 421ms. Found 0 repository interfaces.
15:07:17.185 repair [localhost-startStop-1] INFO  o.s.d.r.c.RepositoryConfigurationDelegate - Bootstrapping Spring Data repositories in DEFAULT mode.
15:07:17.154 repair [localhost-startStop-1] INFO  o.s.d.r.c.RepositoryConfigurationDelegate - Multiple Spring Data modules found, entering strict repository configuration mode!
15:07:06.257 repair [localhost-startStop-1] INFO  cn.demo.repair.RepairApplication - The following profiles are active: dev
15:07:06.256 repair [localhost-startStop-1] DEBUG cn.demo.repair.RepairApplication - Running with Spring Boot v2.1.0.RELEASE, Spring v5.1.2.RELEASE
15:07:06.235 repair [localhost-startStop-1] INFO  cn.demo.repair.RepairApplication - Starting RepairApplication v0.0.1-SNAPSHOT on 10.40.20.119 with PID 102172 (/home/work/data/www/demo-repair/ROOT/WEB-INF/classes started by work in /home/work)

 :: Spring Boot ::        (v2.1.0.RELEASE)
 =========|_|==============|___/=/_/_/_/
  '  |____| .__|_| |_|_| |_\__, | / / / /
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
  .   ____          _            __ _ _

分析：

分析报错信息，看到DruidDataSource初始化后，出现WARN信息，依赖生成bin的时候（最终生成VpServiceImpl的bin时）出现了空指针异常，如下异常信息：

15:07:53.536 repair [localhost-startStop-1] INFO  c.alibaba.druid.pool.DruidDataSource - {dataSource-1} closed
15:07:53.258 repair [localhost-startStop-1] WARN  o.s.b.w.s.c.AnnotationConfigServletWebServerApplicationContext - Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'repairController': Unsatisfied dependency expressed through field 'repairService'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'repairServiceImpl': Unsatisfied dependency expressed through field 'approvalService'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'approvalServiceImpl': Unsatisfied dependency expressed through field 'vpService'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'VpServiceImpl': Invocation of init method failed; nested exception is java.lang.NullPointerException
15:07:37.645 repair [localhost-startStop-1] INFO  c.alibaba.druid.pool.DruidDataSource - {dataSource-1} inited

刚开始以为是SpringBoot集成DruidDataSource出了问题，各种查各种找，没有解决。

在网上搜能引起SpringBoot启动出现以下报错的原因，然也没有解决。

15:07:53.610 repair [localhost-startStop-1] ERROR o.s.boot.SpringApplication - Application run failed Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.

异常意思是：应用程序运行启动ApplicationContext失败，要显示条件报告，请在“debug”模式下重新运行应用程序。

此时觉得可能是出发的方向错了，所以再次回过头来，仔细分析异常堆栈信息，看到两行：

at cn.demo.repair.service.impl.VpServiceImpl.init(VpServiceImpl.java:42)
at java.util.Properties.load(Properties.java:341)

觉得应该是自己程序中：在VpServiceImpl类初始化方法init中，Properties对象load文件时抛出了空指针异常。有了明确方向，开始研究出现问题的代码。

较详细的异常信息摘录：

15:13:34.548 repair [localhost-startStop-1] DEBUG o.springframework.jndi.JndiTemplate - Looking up JNDI object with name [java:comp/env/logging.group]
    ... 74 common frames omitted
    at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.postProcessBeforeInitialization(InitDestroyAnnotationBeanPostProcessor.java:136)
    at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleMetadata.invokeInitMethods(InitDestroyAnnotationBeanPostProcessor.java:307)
    at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleElement.invoke(InitDestroyAnnotationBeanPostProcessor.java:363)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at cn.demo.repair.service.impl.VpServiceImpl.init(VpServiceImpl.java:42)
    at java.util.Properties.load(Properties.java:341)
    at java.util.Properties.load0(Properties.java:353)
    at java.util.Properties$LineReader.readLine(Properties.java:434)
Caused by: java.lang.NullPointerException: null
    ... 61 common frames omitted

结果发现直接用SpringBoot自带的SpringApplication.run方法启动应用程序，VpServiceImpl类的init方法不报错，而且应用程序启动成功，跑业务也正常，但是改造打成ROOT.war包后，部署到服务器的Tomcat上，就报错了，应用程序也启动失败。

哎呀，脑仁疼，怎么办，怎么办，怎么办......

脑子里一闪现，可能是打ROOT.war包出的问题，不对，不能再跑偏(因为之前版本部署ROOT.war没问题)，立即弄死这个想法。

正确的招：分析代码，添加详细的日志打印。

然后问题的根源逐渐浮出水面，直接看代码：

@Service
@Slf4j
public class VpServiceImpl implements VpService{

    @Value("${vp.path}")
    private String vpPath;

    /**
     * VP列表
     */
    private Set<String> vpSet;

    /**
     * Properties文件
     */
    private Properties vpProperties;

    /**
     * 初始化VP列表
     */
    @PostConstruct
    private void init() {
        vpProperties = new Properties();
        try {
            vpProperties.load(ClassLoader.getSystemResourceAsStream(vpPath));
        } catch (IOException e) {
            log.error("Failed to load the vp.properties file. vpPath = " + vpPath + ", IOException : " + e);
        }
        vpSet = vpProperties.stringPropertyNames();
    }

    @Override
    public Set<String> getVpSet() {
        return vpSet;
    }

    @Override
    public String getVpLeader(String username) {
        if (!vpSet.contains(username)) {
            return null;
        }
        String vpLeader = vpProperties.getProperty(username);
        return StringUtils.isEmpty(vpLeader) ? vpProperties.getProperty("vpLeader", "xxx") : vpLeader;
    }

    @Override
    public void setVpSet(Set<String> vpSet) {
        this.vpSet = vpSet;
    }

    @Override
    public boolean addVp(String... vp) {
        if (vpSet == null) {
            vpSet = new HashSet<>();
        }
        return vpSet.addAll(Arrays.asList(vp));
    }

    @Override
    public boolean addVp(List<String> vpList) {
        if (vpSet == null) {
            vpSet = new HashSet<>();
        }
        return vpSet.addAll(vpList);
    }
}

vp.path在application.yml文件中的配置如下：

vp:
  path: vp.properties

vp.properties在SpringBoot工程的resources目录下：

vp.properties文件

代码中Properties对象vpProperties转载InputStream输入流，而InputStream输入流是通过获取vp.properties文件资源转换而来的，这里是有问题的，ClassLoader.getSystemResourceAsStream(vpPath)在实际线上服务器环境中找不到vp.properties文件，所以报了空指针异常，导致线上应用程序启动失败。

解决方法：

代码修改：

@PostConstruct
private void init() {
    vpProperties = new Properties();
    try {
        vpProperties.load(VpServiceImpl.class.getClassLoader().getResourceAsStream(vpPath));
    } catch (Exception e) {
        log.error("Failed to load the vp.properties file. vpPath = " + vpPath + ", Exception : " + e);
    }
    vpSet = vpProperties.stringPropertyNames();
}

修改点：

将vpProperties.load(ClassLoader.getSystemResourceAsStream(vpPath));改为vpProperties.load(VpServiceImpl.class.getClassLoader().getResourceAsStream(vpPath));
catch所有异常，不会导致应用程序启动失败。

总结：

程序报错了，不要瞎考虑，乱认为，一定要仔细研究异常栈信息，仔细研究异常栈信息，仔细研究异常栈信息（重要的事说三遍）。

知识扩展：

写累了，随后再扩展吧。

人面猴
序言：七十年代末，一起剥皮案震惊了整个滨河市，随后出现的几起案子，更是在滨河造成了极大的恐慌，老刑警刘岩，带你破解...
沈念sama阅读 205,132评论 6赞 478
死咒
序言：滨河连续发生了三起死亡事件，死亡现场离奇诡异，居然都是意外死亡，警方通过查阅死者的电脑和手机，发现死者居然都...
沈念sama阅读 87,802评论 2赞 381
救了他两次的神仙让他今天三更去死
文/潘晓璐我一进店门，熙熙楼的掌柜王于贵愁眉苦脸地迎上来，“玉大人，你说我怎么就摊上这事。” “怎么了？”我有些...
开封第一讲书人阅读 151,566评论 0赞 338
道士缉凶录：失踪的卖姜人
文/不坏的土叔我叫张陵，是天一观的道长。经常有香客问我，道长，这世上最难降的妖魔是什么？我笑而不...
开封第一讲书人阅读 54,858评论 1赞 277
港岛之恋（遗憾婚礼）
正文为了忘掉前任，我火速办了婚礼，结果婚礼上，老公的妹妹穿的比我还像新娘。我一直安慰自己，他们只是感情好，可当我...
茶点故事阅读 63,867评论 5赞 368
恶毒庶女顶嫁案：这布局不是一般人想出来的
文/花漫我一把揭开白布。她就那样静静地躺着，像睡着了一般。火红的嫁衣衬着肌肤如雪。梳的纹丝不乱的头发上，一...
开封第一讲书人阅读 48,695评论 1赞 282
城市分裂传说
那天，我揣着相机与录音，去河边找鬼。笑死，一个胖子当着我的面吹牛，可吹牛的内容都是我干的。我是一名探鬼主播，决...
沈念sama阅读 38,064评论 3赞 399
双鸳鸯连环套：你想象不到人心有多黑
文/苍兰香墨我猛地睁开眼，长吁一口气：“原来是场噩梦啊……” “哼！你这毒妇竟也来了？” 一声冷哼从身侧响起，我...
开封第一讲书人阅读 36,705评论 0赞 258
万荣杀人案实录
序言：老挝万荣一对情侣失踪，失踪者是张志新（化名）和其女友刘颖，没想到半个月后，有当地人在树林里发现了一具尸体，经...
沈念sama阅读 42,915评论 1赞 300
护林员之死
正文独居荒郊野岭守林人离奇死亡，尸身上长有42处带血的脓包…… 初始之章·张勋以下内容为张勋视角年9月15日...
茶点故事阅读 35,677评论 2赞 323
白月光启示录
正文我和宋清朗相恋三年，在试婚纱的时候发现自己被绿了。大学时的朋友给我发了我未婚夫和他白月光在一起吃饭的照片。...
茶点故事阅读 37,796评论 1赞 333
活死人
序言：一个原本活蹦乱跳的男人离奇死亡，死状恐怖，灵堂内的尸体忽然破棺而出，到底是诈尸还是另有隐情，我是刑警宁泽，带...
沈念sama阅读 33,432评论 4赞 322
日本核电站爆炸内幕
正文年R本政府宣布，位于F岛的核电站，受9级特大地震影响，放射性物质发生泄漏。R本人自食恶果不足惜，却给世界环境...
茶点故事阅读 39,041评论 3赞 307
男人毒药：我在死后第九天来索命
文/蒙蒙一、第九天我趴在偏房一处隐蔽的房顶上张望。院中可真热闹，春花似锦、人声如沸。这庄子的主人今日做“春日...
开封第一讲书人阅读 29,992评论 0赞 19
一桩弑父案，背后竟有这般阴谋
文/苍兰香墨我抬头看了看天上的太阳。三九已至，却和暖如春，着一层夹袄步出监牢的瞬间，已是汗流浃背。一阵脚步声响...
开封第一讲书人阅读 31,223评论 1赞 260
情欲美人皮
我被黑心中介骗来泰国打工，没想到刚下飞机就差点儿被人妖公主榨干…… 1. 我叫王不留，地道东北人。一个月前我还...
沈念sama阅读 45,185评论 2赞 352
代替公主和亲
正文我出身青楼，却偏偏与公主长得像，于是被迫代替她去往敌国和亲。传闻我的和亲对象是个残疾皇子，可洞房花烛夜当晚...
茶点故事阅读 42,535评论 2赞 343

SpringBoot项目中遇到的异常

问题：

分析：

解决方法：

总结：

知识扩展：

推荐阅读更多精彩内容