Nullpointer exception thrown when running Sprint Boot with Spring MVC

2
votes

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 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

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>

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>

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>
3
springspring-mvcspring-boot
You are mixing Spring 5 with Spring boot 1.5 which supports Spring 4, which probably isn't compatible and with the way you do it you run into conflicting versions (as you will have both 5.0 and 4.3 on the classpath). Next you are trying very hard not to use Spring boot by including your own web.xml and dispatcher servlet loading. - M. Deinum

3 Answers

3
votes

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.

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>

Note that I removed versions from your dependencies so they are taken from parent starter.

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);
    }
}
2
votes

From the exception, its apparently a dependency issue. Can you try using a latest version of spring-boot instead of using 1.5.8.RELEASE?

1
votes

Do not explicitly specify spring mvc or core versions, it will automatically take the compatible version for 1.5.8.RELEASE spring boot.