java - Vaadin 和 Spring - @Autowired 字段为空

标签 java spring vaadin autowired vaadin4spring

我的last question被标记为重复，但答案对我不起作用:-(

我在同一个包中有两个类，我需要从 @Service 查找对象并将结果打印到日志。

package com.example.test.springvaadin.vaadin;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

import com.example.test.springvaadin.entity.Role;
import com.example.test.springvaadin.service.RoleManager;

@Controller
public class Test { 
    private static final Logger logger = LoggerFactory.getLogger(Test.class);

    @Autowired
    private RoleManager roleManager;

    @RequestMapping("/test")
    public void doTest() {
        Role role = roleManager.findById(1);
        logger.info("_ROLE_TEST_ " + role.toString());
        String text = role.getName();       
    }
}

如果我去 http://ip.ip.ip.ip:8080/springvaadin/test 我在日志中看到(好):

14:27:09.126 [tomcat-http--4] INFO  c.e.test.springvaadin.vaadin.Test - _ROLE_TEST_ Role [id=1, name=Test]

还有第二类:

package com.example.test.springvaadin.vaadin;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.vaadin.spring.VaadinUI;

import com.example.test.springvaadin.entity.Role;
import com.example.test.springvaadin.service.RoleManager;
import com.vaadin.server.VaadinRequest;
import com.vaadin.ui.Label;
import com.vaadin.ui.UI;
import com.vaadin.ui.VerticalLayout;

@Controller // @Component do not work too
@VaadinUI
public class MainUI extends UI {

    private static final Logger logger = LoggerFactory.getLogger(MainUI.class);

    @Autowired
    private RoleManager roleManager;

    @Override
    protected void init(VaadinRequest request) {
        logger.info("MAINUI IN INIT");
        final VerticalLayout layout = new VerticalLayout();
        layout.setMargin(true);
        setContent(layout);

        Role role = roleManager.findById(1);
        logger.info("_ROLE_VAADIN_ " + role.toString());
        String text = role.getName();

        Label lblRoleName = new Label(text);
        layout.addComponent(lblRoleName);       
    }
}

它由 web.xml 映射到 /ui。在页面 http://ip.ip.ip.ip:8080/springvaadin/ui 我得到 HTTP 500:

14:29:50.810 [tomcat-http--14] INFO  c.e.test.springvaadin.vaadin.MainUI - MAINUI IN INIT
Čer 29, 2014 2:29:50 ODP. com.vaadin.server.DefaultErrorHandler doDefault
SEVERE: 
java.lang.NullPointerException
    at com.example.test.springvaadin.vaadin.MainUI.init(MainUI.java:40)
    at com.vaadin.ui.UI.doInit(UI.java:641)
    at com.vaadin.server.communication.UIInitHandler.getBrowserDetailsUI(UIInitHandler.java:222)
    at com.vaadin.server.communication.UIInitHandler.synchronizedHandleRequest(UIInitHandler.java:74)
    at com.vaadin.server.SynchronizedRequestHandler.handleRequest(SynchronizedRequestHandler.java:41)
    at com.vaadin.server.VaadinService.handleRequest(VaadinService.java:1405)
    at com.vaadin.server.VaadinServlet.service(VaadinServlet.java:237)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:108)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:409)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1044)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:313)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)

Čer 29, 2014 2:29:50 ODP. org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [MainUI] in context with path [/springvaadin] threw exception [com.vaadin.server.ServiceException: java.lang.NullPointerException] with root cause
java.lang.NullPointerException
    at com.example.test.springvaadin.vaadin.MainUI.init(MainUI.java:40)
    at com.vaadin.ui.UI.doInit(UI.java:641)
    at com.vaadin.server.communication.UIInitHandler.getBrowserDetailsUI(UIInitHandler.java:222)
    at com.vaadin.server.communication.UIInitHandler.synchronizedHandleRequest(UIInitHandler.java:74)
    at com.vaadin.server.SynchronizedRequestHandler.handleRequest(SynchronizedRequestHandler.java:41)
    at com.vaadin.server.VaadinService.handleRequest(VaadinService.java:1405)
    at com.vaadin.server.VaadinServlet.service(VaadinServlet.java:237)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:108)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:409)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1044)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:313)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)

java.lang.NullPointerException 在 com.example.test.springvaadin.vaadin.MainUI.init(MainUI.java:40)

但它是文件中最后一个}之后类的最后一行。

Spring 知道类位于哪里:

<context:component-scan base-package="com.example.test.springvaadin.controller" />
<context:component-scan base-package="com.example.test.springvaadin.dao" />
<context:component-scan base-package="com.example.test.springvaadin.service" />
<context:component-scan base-package="com.example.test.springvaadin.vaadin" />

我做错了什么？使用了注释吗？

源代码:https://dl.dropboxusercontent.com/u/6943408/vaadin-spring_.zip

<小时/>

更新1:

我从 MainUI 类中删除了 @Controller 注释，现在它在第 31 行崩溃 - “Role role = roleManager.findById(1);”有错误:

Čer 29, 2014 8:50:22 ODP. com.vaadin.server.DefaultErrorHandler doDefault
SEVERE: 
java.lang.NullPointerException
    at com.example.test.springvaadin.vaadin.MainUI.init(MainUI.java:31)
    at com.vaadin.ui.UI.doInit(UI.java:641)
    at com.vaadin.server.communication.UIInitHandler.getBrowserDetailsUI(UIInitHandler.java:222)
    at com.vaadin.server.communication.UIInitHandler.synchronizedHandleRequest(UIInitHandler.java:74)
    at com.vaadin.server.SynchronizedRequestHandler.handleRequest(SynchronizedRequestHandler.java:41)
    at com.vaadin.server.VaadinService.handleRequest(VaadinService.java:1405)
    at com.vaadin.server.VaadinServlet.service(VaadinServlet.java:237)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:108)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:409)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1044)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:313)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)

Čer 29, 2014 8:50:22 ODP. org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [MainUI] in context with path [/springvaadin] threw exception [com.vaadin.server.ServiceException: java.lang.NullPointerException] with root cause
java.lang.NullPointerException
    at com.example.test.springvaadin.vaadin.MainUI.init(MainUI.java:31)
    at com.vaadin.ui.UI.doInit(UI.java:641)
    at com.vaadin.server.communication.UIInitHandler.getBrowserDetailsUI(UIInitHandler.java:222)
    at com.vaadin.server.communication.UIInitHandler.synchronizedHandleRequest(UIInitHandler.java:74)
    at com.vaadin.server.SynchronizedRequestHandler.handleRequest(SynchronizedRequestHandler.java:41)
    at com.vaadin.server.VaadinService.handleRequest(VaadinService.java:1405)
    at com.vaadin.server.VaadinServlet.service(VaadinServlet.java:237)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:108)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:409)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1044)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:313)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)

最佳答案

如果您search the repository你可以看到你有 2 或 3 个选择。我个人使用spring-vaadin-integration plugin并根据its documentation ，而不是像使用常规 vaadin servlet 那样提供 UI 类:

<servlet>
    <servlet-name>MainUI</servlet-name>
    <servlet-class>com.vaadin.server.VaadinServlet</servlet-class>      
    <init-param>
        <param-name>UI</param-name>
        <param-value>com.example.test.springvaadin.vaadin.MainUI</param-value>
    </init-param>
</servlet>

您需要提供 spring bean 名称

<servlet>
    <servlet-name>MainUI</servlet-name>
    <servlet-class>ru.xpoft.vaadin.SpringVaadinServlet</servlet-class>
    <init-param>
        <param-name>beanName</param-name>
        <param-value>mainUI</param-value>
    </init-param>
</servlet>

当然，你的 UI 应该用 @Component 和可能 @Scope("prototype") 进行注释:

@Component
@Scope("prototype")
public class MainUI extends UI {    

    @Autowired
    private RoleManager roleManager;

    @Override
    protected void init(VaadinRequest request) {
        final VerticalLayout layout = new VerticalLayout();
        layout.setMargin(true);
        setContent(layout);

        Role r = new Role();
        r.setId(1);
        r.setName("Test");
        roleManager.save(r);

        String text = roleManager.findById(1).getName();

        Label lblRoleName = new Label(text);
        layout.addComponent(lblRoleName);       
    }
}

关于java - Vaadin 和 Spring - @Autowired 字段为空，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/24476122/

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