如何在 Zuul 过滤器中发送 RestTemplate/Request？

Question

我有一个只是直通的核心 MS，并向所有传入请求添加 headers。我试图在 Zuul Filter 中调用一个 Validate Session API ，这样它会在所有请求上添加 headers 之前首先调用它，如果这个错误出现，交易将不继续。但是，似乎我无法在过滤器内发送基本的 rest 模板请求。那我做错了什么还是我错过了其他东西？这是代码片段。

public class WebFilter extends ZuulFilter {

 @Override
    public String filterType() {

        RestTemplate restTemplate = new RestTemplate(new HttpComponentsClientHttpRequestFactory());
        restTemplate.getForEntity(this.loginService.validateCache(hostUrl,validateSessionUrl, ctx.getRequest().getParameter("SessionId")).toUriString(),String.class

         ctx.addZuulRequestHeader("clientid", clientId);
        ctx.addZuulRequestHeader("clientsecret", clientSecret);
        return "pre";
    }
}

而resttemplate部分给出了ff。错误。然而，删除它将使应用程序正常工作，但是我需要那个 rest 模板来调用验证 API。我应该把它放在别的地方，还是别的地方？

2019-12-20 10:11:50.337 ERROR 4224 --- [ main] o.s.boot.SpringApplication : Application startup failed

org.springframework.context.ApplicationContextException: Unable to start embedded container; nested exception is org.springframework.boot.context.embedded.EmbeddedServletContainerException: Unable to start embedded Tomcat at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.onRefresh(EmbeddedWebApplicationContext.java:137) ~[spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE] at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:535) ~[spring-context-4.3.2.RELEASE.jar:4.3.2.RELEASE] at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122) ~[spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE] at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:759) ~[spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE] at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:369) ~[spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:313) ~[spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1185) ~[spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1174) ~[spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE] at com.bdo.fintech.web.core.Application.main(Application.java:26) ~[classes/:na] Caused by: org.springframework.boot.context.embedded.EmbeddedServletContainerException: Unable to start embedded Tomcat at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.initialize(TomcatEmbeddedServletContainer.java:116) ~[spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE] at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.(TomcatEmbeddedServletContainer.java:83) ~[spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE] at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory.getTomcatEmbeddedServletContainer(TomcatEmbeddedServletContainerFactory.java:530) ~[spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE] at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory.getEmbeddedServletContainer(TomcatEmbeddedServletContainerFactory.java:176) ~[spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE] at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.createEmbeddedServletContainer(EmbeddedWebApplicationContext.java:164) ~[spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE] at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.onRefresh(EmbeddedWebApplicationContext.java:134) ~[spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE] ... 8 common frames omitted Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'org.springframework.cloud.netflix.zuul.ZuulConfiguration$ZuulFilterConfiguration': Unsatisfied dependency expressed through field 'filters': Error creating bean with name 'webFilter' defined in com.bdo.fintech.web.core.Application: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.bdo.fintech.web.core.WebFilter]: Factory method 'webFilter' threw exception; nested exception is java.lang.NullPointerException; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'webFilter' defined in com.bdo.fintech.web.core.Application: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.bdo.fintech.web.core.WebFilter]: Factory method 'webFilter' threw exception; nested exception is java.lang.NullPointerException at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:569) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:349) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1214) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:543) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:372) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1123) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1018) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:510) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] at org.springframework.boot.web.servlet.ServletContextInitializerBeans.getOrderedBeansOfType(ServletContextInitializerBeans.java:233) ~[spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE] at org.springframework.boot.web.servlet.ServletContextInitializerBeans.addAsRegistrationBean(ServletContextInitializerBeans.java:181) ~[spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE] at org.springframework.boot.web.servlet.ServletContextInitializerBeans.addAdaptableBeans(ServletContextInitializerBeans.java:162) ~[spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE] at org.springframework.boot.web.servlet.ServletContextInitializerBeans.(ServletContextInitializerBeans.java:79) ~[spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE] at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.getServletContextInitializerBeans(EmbeddedWebApplicationContext.java:241) ~[spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE] at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.selfInitialize(EmbeddedWebApplicationContext.java:228) ~[spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE] at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.access[=12=]0(EmbeddedWebApplicationContext.java:89) ~[spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE] at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.onStartup(EmbeddedWebApplicationContext.java:213) ~[spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE] at org.springframework.boot.context.embedded.tomcat.TomcatStarter.onStartup(TomcatStarter.java:55) ~[spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE] at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5167) ~[tomcat-embed-core-8.5.4.jar:8.5.4] at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:152) ~[tomcat-embed-core-8.5.4.jar:8.5.4] at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1403) ~[tomcat-embed-core-8.5.4.jar:8.5.4] at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1393) ~[tomcat-embed-core-8.5.4.jar:8.5.4] at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) ~[na:na] at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) ~[na:na] at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) ~[na:na] at java.base/java.lang.Thread.run(Thread.java:834) ~[na:na] Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'webFilter' defined in com.bdo.fintech.web.core.Application: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.bdo.fintech.web.core.WebFilter]: Factory method 'webFilter' threw exception; nested exception is java.lang.NullPointerException at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:599) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1123) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1018) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:510) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:207) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1214) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveMultipleBeans(DefaultListableBeanFactory.java:1145) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1049) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1019) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:566) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] ... 35 common frames omitted Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.bdo.fintech.web.core.WebFilter]: Factory method 'webFilter' threw exception; nested exception is java.lang.NullPointerException at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:189) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:588) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] ... 49 common frames omitted Caused by: java.lang.NullPointerException: null at com.bdo.fintech.web.core.WebFilter.filterType(WebFilter.java:89) ~[classes/:na] at com.netflix.zuul.ZuulFilter.disablePropertyName(ZuulFilter.java:89) ~[zuul-core-1.1.0.jar:1.1.0] at com.netflix.zuul.ZuulFilter.(ZuulFilter.java:54) ~[zuul-core-1.1.0.jar:1.1.0] at com.bdo.fintech.web.core.WebFilter.(WebFilter.java:34) ~[classes/:na] at com.bdo.fintech.web.core.Application.webFilter(Application.java:31) ~[classes/:na] at com.bdo.fintech.web.core.Application$$EnhancerBySpringCGLIB$$c625e823.CGLIB$webFilter[=12=]() ~[classes/:na] at com.bdo.fintech.web.core.Application$$EnhancerBySpringCGLIB$$c625e823$$FastClassBySpringCGLIB$$c2090f8d.invoke() ~[classes/:na] at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228) ~[spring-core-4.3.2.RELEASE.jar:4.3.2.RELEASE] at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:356) ~[spring-context-4.3.2.RELEASE.jar:4.3.2.RELEASE] at com.bdo.fintech.web.core.Application$$EnhancerBySpringCGLIB$$c625e823.webFilter() ~[classes/:na] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na] at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na] at java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na] at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:162) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE] ... 50 common frames omitted

Process finished with exit code 1

Answer 1

为您的过滤逻辑覆盖运行() 方法

    @Override
    public Object run() {
        RequestContext ctx = RequestContext.getCurrentContext();
        HttpServletRequest request = ctx.getRequest();

...

        return null;
    }

https://cloud.spring.io/spring-cloud-netflix/multi/multi__router_and_filter_zuul.html#zuul-developer-guide-sample-pre-filter

Answer 2

我能够通过将 RestTemplate 移动到确定请求是否为 null 的条件中来解决此问题

if(ctx.getRequest() != null) {
 // Put Rest template code here
} else {
// Some more code that will handle when the request is null
}

如何在 Zuul 过滤器中发送 RestTemplate/Request？

How to send a RestTemplate/Request inside a Zuul Filter?

java

spring

spring-boot

netflix-zuul