问题
The project that I have is currently set up like so:
Controller:
package com.frclocks.district.controller;
:imports:
@Path("/districts")
@Controller
public class DistrictController {
@Autowired
private DistrictService districtService;
@GET
@Produces(MediaType.APPLICATION_JSON)
public List<District> getDistricts() {
return districtService.getAllDistricts();
}
}
Service (Impl):
package com.frclocks.district.service;
:imports:
@Service("districtService")
@Transactional
public class DistrictServiceImpl implements DistrictService {
@Autowired
private DistrictDao districtDao;
@Override
public List<District> getAllDistricts() {
return districtDao.getAllDistricts();
}
}
Config:
package com.frclocks.config;
:imports:
@Configuration
@ComponentScan(basePackages="com.frclocks", includeFilters=@ComponentScan.Filter(Controller.class))
public class AppConfig { }
The web.xml is empty as I'll be using JavaConfig instead of xml, nor do I have any spring config xml. I have read through several tutorials online, several threads on here, and even browsed through a project at work that I'm developing with which also uses @Autowired and have reached a brick wall. Some of the tutorials say to do something in a main class (such as here: Spring Docs) but the project at work doesn't do anything like that. It has a similar AppConfig (with a few additional, not necessary annotations for me) and no xml config files. What would I be doing wrong? What am I missing here? Thanks!
EDIT: Stack trace for the null:
SEVERE: Servlet.service() for servlet
[com.frclocks.config.FRCLocksApplication] in context with path
[/frclocks] threw exception
org.jboss.resteasy.spi.UnhandledException: java.lang.NullPointerException
at org.jboss.resteasy.core.ExceptionHandler.handleApplicationException(ExceptionHandler.java:78)
at org.jboss.resteasy.core.ExceptionHandler.handleException(ExceptionHandler.java:222)
at org.jboss.resteasy.core.SynchronousDispatcher.writeException(SynchronousDispatcher.java:195)
at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:457)
at org.jboss.resteasy.core.SynchronousDispatcher.lambda$invoke$4(SynchronousDispatcher.java:231)
at org.jboss.resteasy.core.SynchronousDispatcher.lambda$preprocess$0(SynchronousDispatcher.java:137)
at org.jboss.resteasy.core.interception.PreMatchContainerRequestContext.filter(PreMatchContainerRequestContext.java:361)
at org.jboss.resteasy.core.SynchronousDispatcher.preprocess(SynchronousDispatcher.java:140)
at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:217)
at org.jboss.resteasy.plugins.server.servlet.ServletContainerDispatcher.service(ServletContainerDispatcher.java:227)
at org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:56)
at org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:51)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:496)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:650)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:790)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1459)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NullPointerException
at com.frclocks.district.controller.DistrictController.getDistricts(DistrictController.java:27)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.jboss.resteasy.core.MethodInjectorImpl.invoke(MethodInjectorImpl.java:140)
at org.jboss.resteasy.core.ResourceMethodInvoker.internalInvokeOnTarget(ResourceMethodInvoker.java:511)
at org.jboss.resteasy.core.ResourceMethodInvoker.invokeOnTargetAfterFilter(ResourceMethodInvoker.java:402)
at org.jboss.resteasy.core.ResourceMethodInvoker.lambda$invokeOnTarget$0(ResourceMethodInvoker.java:366)
at org.jboss.resteasy.core.interception.PreMatchContainerRequestContext.filter(PreMatchContainerRequestContext.java:361)
at org.jboss.resteasy.core.ResourceMethodInvoker.invokeOnTarget(ResourceMethodInvoker.java:368)
at org.jboss.resteasy.core.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:340)
at org.jboss.resteasy.core.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:313)
at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:441)
... 31 more
回答1:
You have mixed RestEasy and Spring MVC. You should decide for either of those frameworks for your REST endpoints. @Controller is a Spring annotation, while @Path is a JAX-RS annotation. Both together don't work. Currently your Controller is called through RestEasy, which doesn't know anything about your Spring configuration.
来源：https://stackoverflow.com/questions/49905700/autowired-not-working-dependency-is-null