登录
当前位置： 首页 > 知识库问答 >
问题：

实现ApplicationContextAware-ApplicationContext为空

柏夕
2023-03-14

我正在编写一个Tomcat应用程序，它充当一些内部服务的代理。

我已经将Spring项目从基于XML和注释的混合配置切换到基于Java和注释的配置。

import javax.servlet.FilterRegistration;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRegistration;
import org.springframework.web.WebApplicationInitializer;
import org.springframework.web.context.ContextLoaderListener;
import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
import org.springframework.web.servlet.DispatcherServlet;

public class MyAppSpringBoot implements WebApplicationInitializer {

    @Override
    public void onStartup(ServletContext container) throws ServletException {
        initRootContext(container);
        initDispatcherContext(container);
        addFilters(container);
    }

    private void initDispatcherContext(ServletContext container) {
        AnnotationConfigWebApplicationContext servletContext = new AnnotationConfigWebApplicationContext();
        servletContext.register(MyAppDispatcherServletContext.class);
        ServletRegistration.Dynamic dispatcher
                = container.addServlet("myAppDispatcherServlet", new DispatcherServlet(servletContext));
        dispatcher.setLoadOnStartup(1);
        dispatcher.addMapping("/");
    }

    private void initRootContext(ServletContext container) {
        AnnotationConfigWebApplicationContext rootContext = new AnnotationConfigWebApplicationContext();
        rootContext.register(MyAppRootContext.class);
        container.addListener(new ContextLoaderListener(rootContext));
    }

    private void addFilters(ServletContext container) {
        FilterRegistration.Dynamic registration
                = container.addFilter("u3rAuthentication", UserDbAuthenticationFilter.class);
        registration.addMappingForUrlPatterns(null, false, "/entry/*");

        registration = container.addFilter("responseXmlFilter", ResponseTextXmlFilter.class);
        registration.addMappingForUrlPatterns(null, false, "/entry/*");
    }
}

import java.io.File;
import java.io.IOException;
import java.util.Properties;
import javax.persistence.EntityManagerFactory;
import javax.sql.DataSource;
import javax.xml.stream.XMLEventFactory;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLOutputFactory;
import org.apache.tomcat.util.http.fileupload.disk.DiskFileItemFactory;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.jdbc.datasource.lookup.DataSourceLookupFailureException;
import org.springframework.jdbc.datasource.lookup.JndiDataSourceLookup;
import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
import org.springframework.stereotype.Controller;

@Configuration
@ComponentScan(basePackages = "com.application", excludeFilters = @ComponentScan.Filter(Controller.class))
public class MyAppRootContext {

    @Bean
    public DataSource userDbJpaDataSource() throws DataSourceLookupFailureException {

        JndiDataSourceLookup lookup = new JndiDataSourceLookup();
        return lookup.getDataSource("jdbc/userDbPostgres");
    }

    @Bean
    public EntityManagerFactory entityManagerFactory() {
        //return Persistence.createEntityManagerFactory(MyAppConstants.U3R_PERSISTENCE_UNIT);
        LocalContainerEntityManagerFactoryBean fb = new LocalContainerEntityManagerFactoryBean();
        fb.setDataSource(userDbJpaDataSource());
        return fb.getNativeEntityManagerFactory();
    }

    @Bean
    public DiskFileItemFactory diskFileItemFactory() {
        DiskFileItemFactory factory = new DiskFileItemFactory();
        factory.setSizeThreshold(50_000 * 1024);
        factory.setRepository(new File("/WEB-INF/upload"));
        return factory;
    }

    @Bean
    public XMLOutputFactory xmlOutputFactory() {
        return XMLOutputFactory.newInstance();
    }

    @Bean
    public XMLInputFactory xmlInputFactory() {
        return XMLInputFactory.newInstance();
    }

    @Bean
    public XMLEventFactory xmlEventFactory() {
        return XMLEventFactory.newInstance();
    }

    @Bean
    public UrlPairing urlPairing() throws IOException {
        return new UrlPairing(myAppProperties().getProperty("myApp.UrlPairingFile"));
    }

    @Bean
    public Properties myAppProperties() throws IOException {
        Properties p = new Properties();
        p.load(MyAppRootContext.class.getResourceAsStream("/myAppConfig.properties"));
        return p;
    }

    @Bean
    public MyAppXmlFilterWords xmlFilterWords() throws IOException {
        MyAppXmlFilterWords words = MyAppXmlFilterWords.createFilterWords(myAppProperties().getProperty("myApp.xmlFilterWordFile"));
        return words;
    }

}

@Configuration
@ComponentScan(
        basePackages = "de.lgn.doorman",
        includeFilters = @ComponentScan.Filter(Controller.class)
)
public class MyAppDispatcherServletContext
{
    // all beans are defined in root context
    // correct ???
}

根身份验证筛选器的代码：

@Component
public class UserDbAuthenticationFilter implements Filter, ApplicationContextAware
{
    private static final Logger logger = LogManager.getLogger(UserDbAuthenticationFilter.class.getName());

    @Autowired
    EntityManagerFactory emf;

    private ApplicationContext appContext;

    @Override
    public void init(FilterConfig filterConfig)    
    {
        logger.debug("Filter {} initialisiert. App-Context: {} {}", this.getClass().getName(),appContext.hashCode(), appContext);
        // *******************  NullPointerException here *******************
    }

    @Override
    public void destroy()
    { }

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException
    {
        appContext = applicationContext;
    }

    /*
    @PostConstruct    // ***************** this annotation isn't working **********************
    public void filterInit() throws ServletException
    {
        logger.debug("Filter {} initialisiert. App-Context: {} {}", this.getClass().getName(),appContext.hashCode(), appContext);
    }

    */
}

在我的控制器中，applicationcontext是正确的（不是null）。

@Controller
@RequestMapping(value = "entry/**")
public class MyAppProxyController implements ApplicationContextAware
{

    @Autowired
    Properties myAppProperties;

    private ApplicationContext appContext;

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException
    {
        appContext = applicationContext;
    }

    @PostConstruct
    public void init() throws ServletException   // this is working fine
    {
        logger.debug("Controller {} initialisiert. App-Context: {} {}", this.getClass().getName(),
                appContext.hashCode(), appContext);

        logger.debug("Beans im Zugriff von Controller:");
        for (String beanName : appContext.getBeanDefinitionNames())
        {
            logger.debug("          {}", beanName);
        }
        MyAppProxyController controller = (MyAppProxyController) appContext.getBean("myAppProxyController");
        logger.debug("controller-hash im Controller={}", controller.hashCode());
    }
}

我遵循了你所有的指示2。但现在我得到了一个例外：

13-Aug-2015 13:03:27.264 INFO [RMI TCP Connection(3)-127.0.0.1] org.apache.catalina.core.ApplicationContext.log Spring WebApplicationInitializers detected on classpath: [de.lgn.doorman.config.DmSpringBoot@c427b4f]
13-Aug-2015 13:03:27.655 INFO [RMI TCP Connection(3)-127.0.0.1] org.apache.catalina.core.ApplicationContext.log Initializing Spring root WebApplicationContext
13-Aug-2015 13:03:28.308 SEVERE [RMI TCP Connection(3)-127.0.0.1] org.apache.catalina.core.StandardContext.filterStart Exception starting filter responseXmlFilter
 org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'responseXmlFilter' is defined
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeanDefinition(DefaultListableBeanFactory.java:698)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getMergedLocalBeanDefinition(AbstractBeanFactory.java:1174)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:283)

private void addFilters(ServletContext container)
{
    FilterRegistration.Dynamic registration =
            container.addFilter("userDbAuthenticationFilter", DelegatingFilterProxy.class);
    registration.addMappingForUrlPatterns(null, false, "/mapgate/*");

    registration = container.addFilter("prepareRequestFilter", DelegatingFilterProxy.class);
    registration.addMappingForUrlPatterns(null, false, "/mapgate/*");

    registration = container.addFilter("responseTextXmlFilter", DelegatingFilterProxy.class);
    registration.addMappingForUrlPatterns(null, false, "/mapgate/*");
}

@Configuration
@ComponentScan(basePackages = "com.application", excludeFilters = @ComponentScan.Filter(Controller.class))
public class MyAppRootContext
{

    @Bean
    public UserDbAuthenticationFilter userDbAuthenticationFilter()
    {
        return new UserDbAuthenticationFilter();
    }

    @Bean
    public PrepareRequestFilter prepareRequestFilter()
    {
        return new PrepareRequestFilter();
    }

    @Bean
    public ResponseTextXmlFilter responseTextXmlFilter()
    {
        return new ResponseTextXmlFilter();
    }

    @Bean
    public DataSource userDbJpaDataSource() throws DataSourceLookupFailureException
    {

        JndiDataSourceLookup lookup = new JndiDataSourceLookup();
        return lookup.getDataSource("jdbc/userDbPostgres");
    }

    @Bean
    public EntityManagerFactory entityManagerFactory()
    {
        LocalContainerEntityManagerFactoryBean fb = new LocalContainerEntityManagerFactoryBean();
        fb.setDataSource(userDbJpaDataSource());
        return fb.getNativeEntityManagerFactory();
    }
}

public class U3RAuthenticationFilter implements Filter, ApplicationContextAware
{
    private static final Logger logger = LogManager.getLogger(U3RAuthenticationFilter.class.getName());

    @Autowired(required = true)
    EntityManagerFactory entityManagerFactory;

    private ApplicationContext appContext;

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException
    {
        appContext = applicationContext;
    }

    @PostConstruct
    public void filterInit() throws ServletException
    {
        logger.debug("Filter {} initialisiert. App-Context: {} {}", this.getClass().getName(),appContext.hashCode(), appContext);
        logger.debug("Beans accessable by {}:", this.getClass().getName());
        for (String beanName : appContext.getBeanDefinitionNames())
        {
            logger.debug("          {}", beanName);
        }

        logger.debug("EntityManagerFactory: {}", (EntityManagerFactory)appContext.getBean("entityManagerFactory"));
    }
}

20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1] controller-hash im Controller=1481031354
20150814-090718 INFO  [RMI TCP Connection(3)-127.0.0.1] Mapped "{[/mapgate/**],methods=[GET]}" onto protected void com.application.controller.MyAppProxyController.doGet(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse)
20150814-090718 INFO  [RMI TCP Connection(3)-127.0.0.1] Mapped "{[/mapgate/**],methods=[POST]}" onto protected void com.application.controller.MyAppProxyController.doPost(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse) throws javax.servlet.ServletException,java.io.IOException
20150814-090718 INFO  [RMI TCP Connection(3)-127.0.0.1] Looking for @ControllerAdvice: WebApplicationContext for namespace 'myAppDispatcherServlet-servlet': startup date [Fri Aug 14 09:07:18 CEST 2015]; parent: Root WebApplicationContext
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1] Filter com.application.filter.UserDbAuthenticationFilter initialisiert. App-Context: 641348200 WebApplicationContext for namespace 'myAppDispatcherServlet-servlet': startup date [Fri Aug 14 09:07:18 CEST 2015]; parent: Root WebApplicationContext
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1] Beans accessable by com.application.filter.UserDbAuthenticationFilter:
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           org.springframework.context.annotation.internalConfigurationAnnotationProcessor
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           org.springframework.context.annotation.internalAutowiredAnnotationProcessor
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           org.springframework.context.annotation.internalRequiredAnnotationProcessor
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           org.springframework.context.annotation.internalCommonAnnotationProcessor
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           org.springframework.context.annotation.internalPersistenceAnnotationProcessor
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           org.springframework.context.event.internalEventListenerProcessor
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           org.springframework.context.event.internalEventListenerFactory
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           myAppDispatcherServletContext
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           org.springframework.context.annotation.ConfigurationClassPostProcessor.importAwareProcessor
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           org.springframework.context.annotation.ConfigurationClassPostProcessor.enhancedConfigurationProcessor
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           myAppRootContext
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           myAppProxyController
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           org.springframework.web.servlet.config.annotation.DelegatingWebMvcConfiguration
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           requestMappingHandlerMapping
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           mvcContentNegotiationManager
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           viewControllerHandlerMapping
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           beanNameHandlerMapping
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           resourceHandlerMapping
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           mvcResourceUrlProvider
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           defaultServletHandlerMapping
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           requestMappingHandlerAdapter
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           mvcConversionService
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           mvcValidator
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           mvcPathMatcher
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           mvcUrlPathHelper
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           mvcUriComponentsContributor
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           httpRequestHandlerAdapter
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           simpleControllerHandlerAdapter
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           handlerExceptionResolver
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           mvcViewResolver
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           userDbAuthenticationFilter
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           prepareRequestFilter
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           responseTextXmlFilter
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           myAppFilterChain
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           userDbJpaDataSource
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           <b>entityManagerFactory</b>
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           diskFileItemFactory
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           xmlOutputFactory
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           xmlInputFactory
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           xmlEventFactory
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           urlPairing
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           myAppProperties
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1]           xmlFilterWords
20150814-090718 DEBUG [RMI TCP Connection(3)-127.0.0.1] <b>EntityManagerFactory: null</b>

共有1个答案

景令秋
2023-03-14

当应用程序上下文被正确地注入到控制器中时，我假设Spring被正确地初始化了。但是您的筛选器被声明为原始筛选器，而不是spring bean，因此忽略它们上的spring注释。

您有两种方法可以访问应用程序上下文：

>

  • 原始筛选器（未启用Spring）可以通过webapplicationcontext webapplicationcontextutils.getwebapplicationcontext（ServletContext sc）访问根应用程序上下文。例如，可以更改init方法： 

    @Override
public void init(FilterConfig filterConfig)    
{
    ServletContex sc = filterConfig.getServletContext();
    appContext = WebApplicationContextUtils.getWebApplicationContext(sc);
    logger.debug("Filter {} initialisiert. App-Context: {} {}", this.getClass().getName(),appContext.hashCode(), appContext);
}

    private void addFilters(ServletContext container) {
    FilterRegistration.Dynamic registration
            = container.addFilter("u3rAuthentication", DelegatingFilterProxy.class);
    registration.addMappingForUrlPatterns(null, false, "/entry/*");

    registration = container.addFilter("responseXmlFilter", DelegatingFilterProxy.class);
    registration.addMappingForUrlPatterns(null, false, "/entry/*");
}

    @Bean
public UserDbAuthenticationFilter u3rAuthentication() { 
    return new UserDbAuthenticationFilter();
}

@Bean
public ResponseTextXmlFilter responseXmlFilter() { 
    return new ResponseTextXmlFilter();
}

    将不再调用init方法，但这将起作用：

    @PostConstruct
public void filterInit() throws ServletException
{
    logger.debug("Filter {} initialisiert. App-Context: {} {}", this.getClass().getName(),appContext.hashCode(), appContext);
}

    •  类似资料：
    • Spring BeanFactory和ApplicationContext的实现类

      主要内容：1.BeanFactory 的实现,2.ApplicationContext 的实现,3.BeanFactory 和 ApplicationContext的总结1.BeanFactory 的实现 1.1 DefaultListableBeanFactory 实现类 无解析@Bean. @Configuration 的功能 下面代码解析: 先是通过一个工具类得到BeanDefinition, 然后beanFactory 注册BeanDefinition 打印出工厂种的Bean 下面代码通

    • Spring中ApplicationContextAware如何工作？

      问题内容： 在春季，如果实现了bean ，则它可以访问。因此，它能够获得其他豆类。例如 然后可以得到bean的“名称”。 要做到这一点，我们应该把这个里面的，如 这里的bean 不包含属性。我想当spring bean初始化时，就设置了这个属性。但是，这是怎么做的呢？该方法如何调用？ 问题答案： 当spring实例化bean时，它会寻找几个接口，例如和。如果找到它们，则将调用这些方法。例如（非常简

    • 4.8.ApplicationContext

      4.8. ApplicationContext beans包提供了以编程的方式管理和操控bean的基本功能，而context包下的ApplicationContext以一种更加面向框架的方式增强了BeanFactory的功能。多数用户可以采用声明的方式来使用ApplicationContext，甚至不用手动创建它，而通过ContextLoader这样的支持类，把它作为J2EE web应用的一部分自

    • ApplicationContextAware在Spring中如何工作？

      在spring中，如果一个bean实现了，那么它就能够访问。因此它能够得到其他的豆子。例如。 为此，我们应该将这个放在中，例如。 这里的bean不包括属性。我猜当spring bean初始化时，这个属性就被设置了。但这是怎么做到的呢？如何调用方法？

    • BeanFactory与ApplicationContext

      问题内容： 我对Spring Framework还是很陌生，我一直在研究它，并将一些示例应用程序放在一起，以评估Spring MVC以便在即将到来的公司项目中使用。到目前为止，我非常喜欢我在Spring MVC中看到的内容，它似乎非常易于使用，并鼓励您编写对单元测试非常友好的类。 作为练习，我正在为我的一个样本/测试项目编写一种主要方法。我不清楚的一件事是BeanFactory和之间的确切差异Ap

    • Mockito-mock ApplicationContext

      我有一个Springboot应用程序，它在运行时根据用户传递的输入参数从中查找bean。对于这种方法，我试图编写Mockito测试用例，但它不起作用，并抛出NullPointerException。 引导应用程序的类： 我试图为其编写测试用例的类： 我的测试用例如下： 每当我运行测试用例时，它都会在

    相关问答

    在简单的Spring Boot应用程序中使用了哪个ApplicationContext实现？Spring获取当前ApplicationContext为什么要实现finalize（）？spring ApplicationContext bean加载两次在Spring MVC中使用ApplicationContext。

    相关文章

    Java Spring多个ApplicationContext为UIColor实现编码C#实现较为实用的SQLhelperHttpServlet为什么实现Serializable？为angular 2实现ngClassEven ngClassOdd

    相关阅读

    目录实现Spring AOP实现Dubbo AOP实现实战-Swing实现计算器实战-Swing实现记事本

    相关工具

    ApplicationContext for Node.js《Redis 设计与实现》《Apache Spark 设计与实现》md5和sha加密代码实现最简单代码实现九宫格

    相关文档

    Redis 设计与实现如何实现自己的 jQuery常用算法实现方法机器学习算法 Python 实现深入理解 OpenStack 网络实现 Neutron
    快捷导航： 新手教程 算法原理 架构设计 Java进阶 数据库进阶 大厂专栏 面试经验 编程笔记 编程问答 所有专题 文档资料 工具软件 电子书籍 小牛导航
    在线工具： 房贷计算器 个税计算器 Linux命令查询 Json格式化 正则表达式 颜色转换 AES加解密 SHA1加密 MD5加密 毒鸡汤 字数统计 随机密码生成 进制转换 Base64编解码 励志句子
    Copyright © 2019-2024 小牛知识库@xnip.cn. All Rights Reserved.