org.apache.catalina.core.StandardWrapperValve.invoke Allocate exception for servlet [Jersey REST Service] java.lang.NullPointerExceptio

Question

I have tried searching for tutorials out there, but I cannot find any that can solve my problem. Hope anybody can help, many thanks. I try to make a GET request with Jersey, and this is what I got:

12-Dec-2020 20:34:27.342 SEVERE [http-nio-8080-exec-5] org.apache.catalina.core.StandardWrapperValve.invoke Allocate exception for servlet [Jersey REST Service]
    java.lang.NullPointerException
        at org.glassfish.jersey.inject.cdi.se.CdiSeInjectionManager.getInstanceInternal(CdiSeInjectionManager.java:152)
        at org.glassfish.jersey.inject.cdi.se.CdiSeInjectionManager.getInstance(CdiSeInjectionManager.java:142)
        at org.glassfish.jersey.internal.inject.ProviderBinder.bindProvider(ProviderBinder.java:76)
        at org.glassfish.jersey.server.ResourceModelConfigurator.bindProvidersAndResources(ResourceModelConfigurator.java:189)
        at org.glassfish.jersey.server.ResourceModelConfigurator.init(ResourceModelConfigurator.java:87)
        at org.glassfish.jersey.server.ApplicationHandler.initialize(ApplicationHandler.java:365)
        at org.glassfish.jersey.server.ApplicationHandler.lambda$initialize$1(ApplicationHandler.java:316)
        at org.glassfish.jersey.internal.Errors.process(Errors.java:292)
        at org.glassfish.jersey.internal.Errors.process(Errors.java:274)
        at org.glassfish.jersey.internal.Errors.processWithException(Errors.java:232)
        at org.glassfish.jersey.server.ApplicationHandler.initialize(ApplicationHandler.java:315)
        at org.glassfish.jersey.server.ApplicationHandler.<init>(ApplicationHandler.java:282)
        at org.glassfish.jersey.servlet.WebComponent.<init>(WebComponent.java:311)
        at org.glassfish.jersey.servlet.ServletContainer.init(ServletContainer.java:154)
        at org.glassfish.jersey.servlet.ServletContainer.init(ServletContainer.java:346)
        at javax.servlet.GenericServlet.init(GenericServlet.java:158)
        at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1144)
        at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1091)
        at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:763)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:134)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
        at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:543)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
        at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:690)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
        at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:615)
        at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
        at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:818)
        at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1626)
        at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
        at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
        at java.lang.Thread.run(Thread.java:748)

My project.iml file:

<?xml version="1.0" encoding="UTF-8"?>
<module type="JAVA_MODULE" version="4">
  <component name="FacetManager">
    <facet type="web" name="Web">
      <configuration>
        <descriptors>
          <deploymentDescriptor name="web.xml" url="file://$MODULE_DIR$/web/WEB-INF/web.xml" />
        </descriptors>
        <webroots>
          <root url="file://$MODULE_DIR$/web" relative="/" />
        </webroots>
      </configuration>
    </facet>
  </component>
  <component name="NewModuleRootManager" inherit-compiler-output="true">
    <exclude-output />
    <content url="file://$MODULE_DIR$">
      <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
    </content>
    <orderEntry type="inheritedJdk" />
    <orderEntry type="sourceFolder" forTests="false" />
    <orderEntry type="library" scope="PROVIDED" name="Tomcat 8.5.57" level="application_server_libraries" />
    <orderEntry type="library" name="JAX-RS-2.0" level="project" />
    <orderEntry type="module-library">
      <library name="JUnit4">
        <CLASSES>
          <root url="jar://$USER_HOME$/.m2/repository/junit/junit/4.12/junit-4.12.jar!/" />
          <root url="jar://$USER_HOME$/.m2/repository/org/hamcrest/hamcrest-core/1.3/hamcrest-core-1.3.jar!/" />
        </CLASSES>
        <JAVADOC />
        <SOURCES />
      </library>
    </orderEntry>
    <orderEntry type="library" name="javax.servlet.jsp.jstl:javax.servlet.jsp.jstl-api:1.2.1" level="project" />
    <orderEntry type="library" name="org.glassfish.jersey.containers:jersey-container-servlet:2.26" level="project" />
    <orderEntry type="library" name="org.glassfish.jersey.inject:jersey-hk2:2.26" level="project" />
  </component>
</module>

My web.xml file:

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0">
    <display-name>Test REST</display-name>
    <servlet>
        <servlet-name>Jersey REST Service</servlet-name>
        <servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-class>
        <init-param>
            <param-name>jersey.config.server.provider.packages</param-name>
            <param-value>main.service</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
 <servlet-mapping>
        <servlet-name>Jersey REST Service</servlet-name>
        <url-pattern>/rest/*</url-pattern>
    </servlet-mapping>

</web-app>

My class for handling requests:

@Path("rest/theater")
public class TheaterServiceDbAccessImpl implements TheaterService {
    @GET
    @Produces(MediaType.TEXT_HTML)
    public String helloWorld() {
        return "Hello world";
    }
}

I am running this app with IntelliJ and Tomcat version 8.x.

Answer 1

I have understood the problem I got. So when I followed the tutorial, I wasn't careful to include a @Path annotation above the class definition. So turn out to compile the program, just put the complication error and NullPointerException aside, you need to first declare the Path for the class. In my case, it'd be @Path("/rest") , and above the method that I want to get information about the theater, I need to include @Path("/theater") . So for example, http://localhost:8080/rest/theater will give me Hello world .