Почему Spring Dependency Injection @Autowired выдает исключение NullPointerException в сервлете? ⇐ JAVA

[Anonymous]

Структура проекта:

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TestController.java

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package com.mypack;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;

/**
* Servlet implementation class Test
*/
@WebServlet("/test")
@Controller
public class TestController extends HttpServlet {
private static final long serialVersionUID = 1L;

@Autowired
private TestManager testManager;

public TestManager getTestManager() {
return testManager;
}

public void setTestManager(TestManager testManager) {
this.testManager = testManager;
}

public TestController() {
super();
}

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.getWriter().append("Served at: ").append(request.getContextPath());

String name=testManager.getName();
PrintWriter pw=response.getWriter();
pw.write(name);
}

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}

}

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TestManager.java

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package com.mypack;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Configurable;
import org.springframework.stereotype.Service;

@Service("testManager")
public class TestManager {

@Autowired
private TestDao testDao;

public String getName(){
return testDao.getName();
}

public TestDao getTestDao() {
return testDao;
}

public void setTestDao(TestDao testDao) {
this.testDao = testDao;
}
}

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TestDao.java

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package com.mypack;

import org.springframework.stereotype.Repository;

@Repository("testDao")
public class TestDao {
public String getName(){
return "Randhir";
}
}

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spring.xml

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web.xml

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SpringIOCWeb

index.jsp



org.springframework.web.context.ContextLoaderListener



contextConfigLocation

/WEB-INF/spring.xml

Консоль сервера:

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INFO: 1 Spring WebApplicationInitializers detected on classpath
Jan 21, 2017 7:50:39 PM org.apache.catalina.core.ApplicationContext log
INFO: Initializing Spring root WebApplicationContext
Jan 21, 2017 7:50:39 PM org.springframework.web.context.ContextLoader initWebApplicationContext
INFO: Root WebApplicationContext: initialization started
Jan 21, 2017 7:50:39 PM org.springframework.context.support.AbstractApplicationContext prepareRefresh
INFO: Refreshing Root WebApplicationContext: startup date [Sat Jan 21 19:50:39 IST 2017]; root of context hierarchy
Jan 21, 2017 7:50:39 PM org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from ServletContext resource [/WEB-INF/spring.xml]
Jan 21, 2017 7:50:40 PM org.springframework.web.context.ContextLoader initWebApplicationContext
INFO: Root WebApplicationContext: initialization completed in 731 ms
Jan 21, 2017 7:50:40 PM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["http-nio-8090"]
Jan 21, 2017 7:50:40 PM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["ajp-nio-8009"]
Jan 21, 2017 7:50:40 PM org.apache.catalina.startup.Catalina start
INFO: Server startup in 2836 ms
Jan 21, 2017 7:50:45 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [com.mypack.TestController] in context with path [] threw exception
java.lang.NullPointerException
at com.mypack.TestController.doGet(TestController.java:43)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:618)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:506)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:610)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:537)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1081)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:658)
at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:222)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1566)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1523)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:724)

Контейнер IOC создаст экземпляр компонента и назначит ссылку на объект с помощью метода установки. Верна ли моя концепция?
Но здесь @Autowired не присваивает ссылку на объект.
Я использовал главную
code> с ApplicationContext и getBean() для изучения Spring.
Но как конфигурация компонента работает с сервлетом?

Подробнее здесь: https://stackoverflow.com/questions/417 ... -in-a-serv