使用 Spring MVC 运行 Sprint Boot 时抛出空指针异常 [英] Nullpointer exception thrown when running Sprint Boot with Spring MVC
问题描述
我正在使用 spring boot 构建 spring mvc 项目，但我无法启动我的 web 应用程序.我遵循了几个教程，但无法弄清楚.我可以使用 spring boot 启动我的应用程序，但是当我添加 Spring mvc 时，它开始抛出错误.我收到以下错误
I am building spring mvc project with spring boot but I am unable to start my web application . I have followed the couple of tutorials but cant figure it out. I could start my application with spring boot but when i add Spring mvc, it starts to throw an error. I am getting a following error
java.lang.NullPointerException: null在 org.springframework.core.BridgeMethodResolver.findBridgedMethod(BridgeMethodResolver.java:60)在 org.springframework.beans.GenericTypeAwarePropertyDescriptor.(GenericTypeAwarePropertyDescriptor.java:70)在 org.springframework.beans.CachedIntrospectionResults.buildGenericTypeAwarePropertyDescriptor(CachedIntrospectionResults.java:366)在 org.springframework.beans.CachedIntrospectionResults.(CachedIntrospectionResults.java:302)在 org.springframework.beans.CachedIntrospectionResults.forClass(CachedIntrospectionResults.java:189)在 org.springframework.beans.BeanUtils.getPropertyDescriptors(BeanUtils.java:354)在 org.springframework.boot.bind.PropertiesConfigurationFactory.getNames(PropertiesConfigurationFactory.java:288)在 org.springframework.boot.bind.PropertiesConfigurationFactory.doBindPropertiesToTarget(PropertiesConfigurationFactory.java:269)在 org.springframework.boot.bind.PropertiesConfigurationFactory.bindPropertiesToTarget(PropertiesConfigurationFactory.java:240)在 org.springframework.boot.context.config.ConfigFileApplicationListener.bindToSpringApplication(ConfigFileApplicationListener.java:241)在 org.springframework.boot.context.config.ConfigFileApplicationListener.postProcessEnvironment(ConfigFileApplicationListener.java:197)在 org.springframework.boot.context.config.ConfigFileApplicationListener.onApplicationEnvironmentPreparedEvent(ConfigFileApplicationListener.java:182)在 org.springframework.boot.context.config.ConfigFileApplicationListener.onApplicationEvent(ConfigFileApplicationListener.java:168)在 org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172)在 org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165)在 org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139)在 org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:127)在 org.springframework.boot.context.event.EventPublishingRunListener.environmentPrepared(EventPublishingRunListener.java:74)在 org.springframework.boot.SpringApplicationRunListeners.environmentPrepared(SpringApplicationRunListeners.java:54)在 org.springframework.boot.SpringApplication.prepareEnvironment(SpringApplication.java:325)在 org.springframework.boot.SpringApplication.run(SpringApplication.java:296)在 org.springframework.boot.SpringApplication.run(SpringApplication.java:1118)在 org.springframework.boot.SpringApplication.run(SpringApplication.java:1107)在 com.azzimov.search.BootStarter.StartApplication.main(StartApplication.java:17)在 sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)在 sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)在 sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)在 java.lang.reflect.Method.invoke(Method.java:498)在 org.springframework.boot.maven.AbstractRunMojo$LaunchRunner.run(AbstractRunMojo.java:527)在 java.lang.Thread.run(Thread.java:745) [警告] java.lang.reflect.InvocationTargetException在 sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)在 sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)在 sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)在 java.lang.reflect.Method.invoke(Method.java:498)在 org.springframework.boot.maven.AbstractRunMojo$LaunchRunner.run(AbstractRunMojo.java:527)在 java.lang.Thread.run(Thread.java:745) 引起:java.lang.NullPointerException在 org.springframework.core.BridgeMethodResolver.findBridgedMethod(BridgeMethodResolver.java:60)在 org.springframework.beans.GenericTypeAwarePropertyDescriptor.(GenericTypeAwarePropertyDescriptor.java:70)在 org.springframework.beans.CachedIntrospectionResults.buildGenericTypeAwarePropertyDescriptor(CachedIntrospectionResults.java:366)在 org.springframework.beans.CachedIntrospectionResults.(CachedIntrospectionResults.java:302)在 org.springframework.beans.CachedIntrospectionResults.forClass(CachedIntrospectionResults.java:189)在 org.springframework.beans.BeanUtils.getPropertyDescriptors(BeanUtils.java:354)在 org.springframework.boot.bind.PropertiesConfigurationFactory.getNames(PropertiesConfigurationFactory.java:288)在 org.springframework.boot.bind.PropertiesConfigurationFactory.doBindPropertiesToTarget(PropertiesConfigurationFactory.java:269)在 org.springframework.boot.bind.PropertiesConfigurationFactory.bindPropertiesToTarget(PropertiesConfigurationFactory.java:240)在 org.springframework.boot.context.config.ConfigFileApplicationListener.bindToSpringApplication(ConfigFileApplicationListener.java:241)在 org.springframework.boot.context.config.ConfigFileApplicationListener.postProcessEnvironment(ConfigFileApplicationListener.java:197)在 org.springframework.boot.context.config.ConfigFileApplicationListener.onApplicationEnvironmentPreparedEvent(ConfigFileApplicationListener.java:182)在 org.springframework.boot.context.config.ConfigFileApplicationListener.onApplicationEvent(ConfigFileApplicationListener.java:168)在 org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172)在 org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165)在 org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139)在 org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:127)在 org.springframework.boot.context.event.EventPublishingRunListener.environmentPrepared(EventPublishingRunListener.java:74)在 org.springframework.boot.SpringApplicationRunListeners.environmentPrepared(SpringApplicationRunListeners.java:54)在 org.springframework.boot.SpringApplication.prepareEnvironment(SpringApplication.java:325)在 org.springframework.boot.SpringApplication.run(SpringApplication.java:296)在 org.springframework.boot.SpringApplication.run(SpringApplication.java:1118)在 org.springframework.boot.SpringApplication.run(SpringApplication.java:1107)在 com.azzimov.search.BootStarter.StartApplication.main(StartApplication.java:17)... 6个
java.lang.NullPointerException: null at org.springframework.core.BridgeMethodResolver.findBridgedMethod(BridgeMethodResolver.java:60) at org.springframework.beans.GenericTypeAwarePropertyDescriptor.(GenericTypeAwarePropertyDescriptor.java:70) at org.springframework.beans.CachedIntrospectionResults.buildGenericTypeAwarePropertyDescriptor(CachedIntrospectionResults.java:366) at org.springframework.beans.CachedIntrospectionResults.(CachedIntrospectionResults.java:302) at org.springframework.beans.CachedIntrospectionResults.forClass(CachedIntrospectionResults.java:189) at org.springframework.beans.BeanUtils.getPropertyDescriptors(BeanUtils.java:354) at org.springframework.boot.bind.PropertiesConfigurationFactory.getNames(PropertiesConfigurationFactory.java:288) at org.springframework.boot.bind.PropertiesConfigurationFactory.doBindPropertiesToTarget(PropertiesConfigurationFactory.java:269) at org.springframework.boot.bind.PropertiesConfigurationFactory.bindPropertiesToTarget(PropertiesConfigurationFactory.java:240) at org.springframework.boot.context.config.ConfigFileApplicationListener.bindToSpringApplication(ConfigFileApplicationListener.java:241) at org.springframework.boot.context.config.ConfigFileApplicationListener.postProcessEnvironment(ConfigFileApplicationListener.java:197) at org.springframework.boot.context.config.ConfigFileApplicationListener.onApplicationEnvironmentPreparedEvent(ConfigFileApplicationListener.java:182) at org.springframework.boot.context.config.ConfigFileApplicationListener.onApplicationEvent(ConfigFileApplicationListener.java:168) at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172) at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165) at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139) at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:127) at org.springframework.boot.context.event.EventPublishingRunListener.environmentPrepared(EventPublishingRunListener.java:74) at org.springframework.boot.SpringApplicationRunListeners.environmentPrepared(SpringApplicationRunListeners.java:54) at org.springframework.boot.SpringApplication.prepareEnvironment(SpringApplication.java:325) at org.springframework.boot.SpringApplication.run(SpringApplication.java:296) at org.springframework.boot.SpringApplication.run(SpringApplication.java:1118) at org.springframework.boot.SpringApplication.run(SpringApplication.java:1107) at com.azzimov.search.BootStarter.StartApplication.main(StartApplication.java:17) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.springframework.boot.maven.AbstractRunMojo$LaunchRunner.run(AbstractRunMojo.java:527) at java.lang.Thread.run(Thread.java:745) [WARNING] java.lang.reflect.InvocationTargetException at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.springframework.boot.maven.AbstractRunMojo$LaunchRunner.run(AbstractRunMojo.java:527) at java.lang.Thread.run(Thread.java:745) Caused by: java.lang.NullPointerException at org.springframework.core.BridgeMethodResolver.findBridgedMethod(BridgeMethodResolver.java:60) at org.springframework.beans.GenericTypeAwarePropertyDescriptor.(GenericTypeAwarePropertyDescriptor.java:70) at org.springframework.beans.CachedIntrospectionResults.buildGenericTypeAwarePropertyDescriptor(CachedIntrospectionResults.java:366) at org.springframework.beans.CachedIntrospectionResults.(CachedIntrospectionResults.java:302) at org.springframework.beans.CachedIntrospectionResults.forClass(CachedIntrospectionResults.java:189) at org.springframework.beans.BeanUtils.getPropertyDescriptors(BeanUtils.java:354) at org.springframework.boot.bind.PropertiesConfigurationFactory.getNames(PropertiesConfigurationFactory.java:288) at org.springframework.boot.bind.PropertiesConfigurationFactory.doBindPropertiesToTarget(PropertiesConfigurationFactory.java:269) at org.springframework.boot.bind.PropertiesConfigurationFactory.bindPropertiesToTarget(PropertiesConfigurationFactory.java:240) at org.springframework.boot.context.config.ConfigFileApplicationListener.bindToSpringApplication(ConfigFileApplicationListener.java:241) at org.springframework.boot.context.config.ConfigFileApplicationListener.postProcessEnvironment(ConfigFileApplicationListener.java:197) at org.springframework.boot.context.config.ConfigFileApplicationListener.onApplicationEnvironmentPreparedEvent(ConfigFileApplicationListener.java:182) at org.springframework.boot.context.config.ConfigFileApplicationListener.onApplicationEvent(ConfigFileApplicationListener.java:168) at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172) at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165) at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139) at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:127) at org.springframework.boot.context.event.EventPublishingRunListener.environmentPrepared(EventPublishingRunListener.java:74) at org.springframework.boot.SpringApplicationRunListeners.environmentPrepared(SpringApplicationRunListeners.java:54) at org.springframework.boot.SpringApplication.prepareEnvironment(SpringApplication.java:325) at org.springframework.boot.SpringApplication.run(SpringApplication.java:296) at org.springframework.boot.SpringApplication.run(SpringApplication.java:1118) at org.springframework.boot.SpringApplication.run(SpringApplication.java:1107) at com.azzimov.search.BootStarter.StartApplication.main(StartApplication.java:17) ... 6 more
我的 pom.xml 是
My pom.xml is
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.8.RELEASE</version>
</parent>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>4.0.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>5.0.1.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>5.0.1.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>5.0.1.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<version>1.5.8.RELEASE</version>
</dependency>
</dependencies>
<build>
<finalName>azzimov-search</finalName>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.7.0</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.tomcat.maven</groupId>
<artifactId>tomcat7-maven-plugin</artifactId>
<version>2.2</version>
</plugin>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
<resources>
<resource>
<directory>src/clients</directory>
</resource>
</resources>
</build>
我的 web.xml 是
My web.xml is
<webapp>
<servlet>
<servlet-name>dispatcher</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/web-config.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>dispatcher</servlet-name>
<url-pattern>/gw/*</url-pattern>
</servlet-mapping>
</web-app>
我的 web-config.xml 是
My web-config.xml is
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd ">
<mvc:annotation-driven />
<context:component-scan base-package="com.project.book" />
</beans>
推荐答案
您正在尝试将 Spring Boot 1.5 与 Spring 5 混合使用.这不会起作用，因为它们不兼容.如果你真的需要 Spring Framework 5，你应该使用 Spring Boot 2.x starter parent.
You are trying to mix Spring Boot 1.5 with Spring 5. This won't work this way as they are not compatible. If you really need Spring Framework 5 you should use Spring Boot 2.x starter parent.
根据您的需要，您可以将下面的 pom.xml 将 1.5.8.RELEASE 更改为 2.0.0.M5，或者保持原样.
Depending on your needs you can take the pom.xml below and change 1.5.8.RELEASE to 2.0.0.M5, or leave it as is.
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.8.RELEASE</version>
</parent>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
</dependencies>
<build>
<finalName>azzimov-search</finalName>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
<resources>
<resource>
<directory>src/clients</directory>
</resource>
</resources>
</build>
请注意，我从您的依赖项中删除了版本，因此它们是从父启动器中获取的.
Note that I removed versions from your dependencies so they are taken from parent starter.
此外，删除您的 web.xml 和 web-config.xml，因为它们对于 Spring Boot 不是必需的.而是在您的根包(大概是 com.project 或 com.project.book)中创建一个类:
Also, remove your web.xml and web-config.xml as they are not necessary for Spring Boot. Instead create a class in your root package (presumably com.project, or com.project.book):
@SpringBootApplication
public class BookApp {
public static void main(String[] args) {
SpringApplication.run(BookApp.class, args);
}
}
这篇关于使用 Spring MVC 运行 Sprint Boot 时抛出空指针异常的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
