Spring Rest（MVC + 安全性）Java 配置："Cannot initialize context because there is already a root application context present"

Question

我是 Spring 的新手，我已经遇到了一个关于基本配置的非常奇怪的问题。

Caused by: java.lang.IllegalStateException: Cannot initialize context because there is already a root application context present - check whether you have multiple ContextLoader* definitions in your web.xml! at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:297) at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:107) at io.undertow.servlet.core.ApplicationListeners.contextInitialized(ApplicationListeners.java:173) at io.undertow.servlet.core.DeploymentManagerImpl.deploy(DeploymentManagerImpl.java:194) ... 7 more

我需要两种不同的 REST servlet：一种用于内部调用（查看服务器），一种用于外部 API。我还希望两个 servlet 共享一些服务，所以我使用 SpringRootConfiguration 来扫描包含两个拦截器和一个服务的包。

所有配置都在 Java 中完成，只有上下文和侦听器在 web.xml

中完成

web.xml

<context-param>
    <param-name>contextClass</param-name>
    <param-value>
        org.springframework.web.context.support.AnnotationConfigWebApplicationContext
    </param-value>
</context-param>

<listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>

SpringRestExternalAppInitializer

@Override
protected Class<?>[] getRootConfigClasses() {
    return new Class[]{SpringRootConfiguration.class};
}

@Override
protected Class<?>[] getServletConfigClasses() {
    return new Class[]{SpringRestExternalConfiguration.class};
}

@Override
protected String[] getServletMappings() {
    return new String[]{"/api/*"};
}

@Override
protected String getServletName() {
    return "restexternal";
}

SpringRootConfiguration

@ComponentScan({"be.xperthis.common"})
@Configuration
public class SpringRootConfiguration {

}

SpringRestExternalConfiguration

@ComponentScan("com.polymedis.result.web.api")
@Configuration
public class SpringRestExternalConfiguration extends WebMvcConfigurationSupport {

@Autowired
private NoCacheHandler noCacheHandler;

@Autowired
private RestMetricHandler restMetrics;

@Override
public void addInterceptors(final InterceptorRegistry registry) {
    registry.addInterceptor(noCacheHandler);
    registry.addInterceptor(restMetrics);
}

@Override
public void configureDefaultServletHandling(final DefaultServletHandlerConfigurer configurer) {
    configurer.enable();
}

@Override
public void configureMessageConverters(final List<HttpMessageConverter<?>> converters) {
    ....
}

@Override
public RequestMappingHandlerMapping createRequestMappingHandlerMapping() {
    return new ApiVersionRequestMappingHandlerMapping(); //used to check a custom annotation on every RestController methods
}
}

理论上，应该有第二个 Rest 配置（内部），但我在试图理解异常时暂时删除了它...

注意：按照 Spring 安全教程，我在将 SpringSecurityConfiguration 放入 getRootConfigClasses() { ... }

时遇到了同样的错误

我应该 remove/add 来自 web.xml 的东西吗？我正在使用 Wildfly 8，我已经不得不为 Wildfly 中的错误找到解决方法：如果 spring 库（罐子）未添加到 WEB-Inf/lib文件夹...

Answer 1

好的，我找到了解决方案。我现在没有覆盖两次 AbstractAnnotationConfigDispatcherServletInitializer，而是使用一个 class 实现 WebApplicationInitializer，并且我在这个 class.

中构建了我的两个 servlet

public class SpringAppInitializer implements WebApplicationInitializer {

@Override
public void onStartup(final ServletContext servletContext) throws ServletException {
    final AnnotationConfigWebApplicationContext rootContext = new AnnotationConfigWebApplicationContext();
    rootContext.register(SpringRootConfiguration.class, SpringSecurityConfig.class);
    servletContext.addListener(new ContextLoaderListener(rootContext));

    // Internal REST
    buildInternalRestContext(servletContext, rootContext);

    // External REST
    buildExternalRestContext(servletContext, rootContext);

    ...
}

public void buildExternalRestContext(final ServletContext servletContext, final AnnotationConfigWebApplicationContext rootContext) {
    final AnnotationConfigWebApplicationContext externalRestContext = new AnnotationConfigWebApplicationContext();
    externalRestContext.setParent(rootContext);
    externalRestContext.register(SpringRestExternalConfiguration.class);

    final ServletRegistration.Dynamic externalRestServlet = servletContext.addServlet("externalrest", new DispatcherServlet(externalRestContext));
    externalRestServlet.addMapping("/api/*");
}

public void buildInternalRestContext(final ServletContext servletContext, final AnnotationConfigWebApplicationContext rootContext) {
    final AnnotationConfigWebApplicationContext internalRestContext = new AnnotationConfigWebApplicationContext();
    internalRestContext.setParent(rootContext);
    internalRestContext.register(SpringRestConfiguration.class);

    final ServletRegistration.Dynamic restDispatcherServlet = servletContext.addServlet("rest", new DispatcherServlet(internalRestContext));
    restDispatcherServlet.addMapping("/rest/*");
}

}

我现在将继续设置 SpringSecurity，但这是另一个话题:)

Spring Rest（MVC + 安全性）Java 配置："Cannot initialize context because there is already a root application context present"

SpringRest (MVC + Security) Java Configuration : "Cannot initialize context because there is already a root application context present"

java

spring

spring-security

spring-rest