Springboot 2.x 里 jersey 不支持多个Application ，推荐从org.glassfish.jersey.server.ResourceConfig 继承，指定唯一的ApplicationPath. 从下面的一个例子定义来看一下如何定义的
import org.glassfish.jersey.server.ResourceConfig;
import org.springframework.context.annotation.Configuration;
import javax.annotation.PostConstruct;
import javax.inject.Inject;
import javax.inject.Named;
import javax.ws.rs.ApplicationPath;
import javax.ws.rs.core.Feature;
@Configuration
@ApplicationPath("/samplesvc")
public class SampleResourceConfig extends ResourceConfig {
@PostConstruct
public void init() {
register(SampleResource.class);
}
}
只有一个Application就意味着只能有一个context，大家只能有一套filter，providers 等等。 如果希望根据不同的path来配置不同类型的filter，provider，resource等的组合，就需要支持多个Application。如何改变Springboot 的行为，先从JerseyAutoConfiguration了解是如何配置的。
/*
* Copyright 2012-2019 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
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package org.springframework.boot.autoconfigure.jersey;
import java.util.Collections;
import java.util.EnumSet;
import javax.annotation.PostConstruct;
import javax.servlet.DispatcherType;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRegistration;
import javax.ws.rs.ext.ContextResolver;
import javax.xml.bind.annotation.XmlElement;
import com.fasterxml.jackson.databind.AnnotationIntrospector;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.cfg.MapperConfig;
import com.fasterxml.jackson.module.jaxb.JaxbAnnotationIntrospector;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.glassfish.jersey.jackson.JacksonFeature;
import org.glassfish.jersey.server.ResourceConfig;
import org.glassfish.jersey.server.spring.SpringComponentProvider;
import org.glassfish.jersey.servlet.ServletContainer;
import org.glassfish.jersey.servlet.ServletProperties;
import org.springframework.beans.factory.ObjectProvider;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.AutoConfigureAfter;
import org.springframework.boot.autoconfigure.AutoConfigureBefore;
import org.springframework.boot.autoconfigure.AutoConfigureOrder;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.boot.autoconfigure.condition.ConditionalOnSingleCandidate;
import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication;
import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication.Type;
import org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration;
import org.springframework.boot.autoconfigure.web.servlet.ConditionalOnMissingFilterBean;
import org.springframework.boot.autoconfigure.web.servlet.DefaultJerseyApplicationPath;
import org.springframework.boot.autoconfigure.web.servlet.DispatcherServletAutoConfiguration;
import org.springframework.boot.autoconfigure.web.servlet.JerseyApplicationPath;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.boot.web.servlet.DynamicRegistrationBean;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.Ordered;
import org.springframework.core.annotation.Order;
import org.springframework.util.ClassUtils;
import org.springframework.web.WebApplicationInitializer;
import org.springframework.web.context.ServletContextAware;
import org.springframework.web.filter.RequestContextFilter;
/**
* {@link EnableAutoConfiguration Auto-configuration} for Jersey.
*
* @author Dave Syer
* @author Andy Wilkinson
* @author Eddú Meléndez
* @author Stephane Nicoll
* @since 1.2.0
*/
@Configuration(proxyBeanMethods = false)
@ConditionalOnClass({ SpringComponentProvider.class, ServletRegistration.class })
@ConditionalOnBean(type = "org.glassfish.jersey.server.ResourceConfig")
@ConditionalOnWebApplication(type = Type.SERVLET)
@AutoConfigureOrder(Ordered.HIGHEST_PRECEDENCE)
@AutoConfigureBefore(DispatcherServletAutoConfiguration.class)
@AutoConfigureAfter(JacksonAutoConfiguration.class)
@EnableConfigurationProperties(JerseyProperties.class)
public class JerseyAutoConfiguration implements ServletContextAware {
private static final Log logger = LogFactory.getLog(JerseyAutoConfiguration.class);
private final JerseyProperties jersey;
private final ResourceConfig config;
private final ObjectProvider customizers;
public JerseyAutoConfiguration(JerseyProperties jersey, ResourceConfig config,
ObjectProvider customizers) {
this.jersey = jersey;
this.config = config;
this.customizers = customizers;
}
@PostConstruct
public void path() {
customize();
}
private void customize() {
this.customizers.orderedStream().forEach((customizer) -> customizer.customize(this.config));
}
@Bean
@ConditionalOnMissingFilterBean(RequestContextFilter.class)
public FilterRegistrationBean requestContextFilter() {
FilterRegistrationBean registration = new FilterRegistrationBean<>();
registration.setFilter(new RequestContextFilter());
registration.setOrder(this.jersey.getFilter().getOrder() - 1);
registration.setName("requestContextFilter");
return registration;
}
@Bean
@ConditionalOnMissingBean
public JerseyApplicationPath jerseyApplicationPath() {
return new DefaultJerseyApplicationPath(this.jersey.getApplicationPath(), this.config);
}
@Bean
@ConditionalOnMissingBean(name = "jerseyFilterRegistration")
@ConditionalOnProperty(prefix = "spring.jersey", name = "type", havingValue = "filter")
public FilterRegistrationBean jerseyFilterRegistration(JerseyApplicationPath applicationPath) {
FilterRegistrationBean registration = new FilterRegistrationBean<>();
registration.setFilter(new ServletContainer(this.config));
registration.setUrlPatterns(Collections.singletonList(applicationPath.getUrlMapping()));
registration.setOrder(this.jersey.getFilter().getOrder());
registration.addInitParameter(ServletProperties.FILTER_CONTEXT_PATH, stripPattern(applicationPath.getPath()));
addInitParameters(registration);
registration.setName("jerseyFilter");
registration.setDispatcherTypes(EnumSet.allOf(DispatcherType.class));
return registration;
}
private String stripPattern(String path) {
if (path.endsWith("/*")) {
path = path.substring(0, path.lastIndexOf("/*"));
}
return path;
}
@Bean
@ConditionalOnMissingBean(name = "jerseyServletRegistration")
@ConditionalOnProperty(prefix = "spring.jersey", name = "type", havingValue = "servlet", matchIfMissing = true)
public ServletRegistrationBean jerseyServletRegistration(JerseyApplicationPath applicationPath) {
ServletRegistrationBean registration = new ServletRegistrationBean<>(
new ServletContainer(this.config), applicationPath.getUrlMapping());
addInitParameters(registration);
registration.setName(getServletRegistrationName());
registration.setLoadOnStartup(this.jersey.getServlet().getLoadOnStartup());
return registration;
}
private String getServletRegistrationName() {
return ClassUtils.getUserClass(this.config.getClass()).getName();
}
private void addInitParameters(DynamicRegistrationBean registration) {
this.jersey.getInit().forEach(registration::addInitParameter);
}
@Override
public void setServletContext(ServletContext servletContext) {
String servletRegistrationName = getServletRegistrationName();
ServletRegistration registration = servletContext.getServletRegistration(servletRegistrationName);
if (registration != null) {
if (logger.isInfoEnabled()) {
logger.info("Configuring existing registration for Jersey servlet '" + servletRegistrationName + "'");
}
registration.setInitParameters(this.jersey.getInit());
}
}
@Order(Ordered.HIGHEST_PRECEDENCE)
public static final class JerseyWebApplicationInitializer implements WebApplicationInitializer {
@Override
public void onStartup(ServletContext servletContext) throws ServletException {
// We need to switch *off* the Jersey WebApplicationInitializer because it
// will try and register a ContextLoaderListener which we don't need
servletContext.setInitParameter("contextConfigLocation", "");
}
}
@Configuration(proxyBeanMethods = false)
@ConditionalOnClass(JacksonFeature.class)
@ConditionalOnSingleCandidate(ObjectMapper.class)
static class JacksonResourceConfigCustomizer {
@Bean
ResourceConfigCustomizer resourceConfigCustomizer(final ObjectMapper objectMapper) {
return (ResourceConfig config) -> {
config.register(JacksonFeature.class);
config.register(new ObjectMapperContextResolver(objectMapper), ContextResolver.class);
};
}
@Configuration(proxyBeanMethods = false)
@ConditionalOnClass({ JaxbAnnotationIntrospector.class, XmlElement.class })
static class JaxbObjectMapperCustomizer {
@Autowired
void addJaxbAnnotationIntrospector(ObjectMapper objectMapper) {
JaxbAnnotationIntrospector jaxbAnnotationIntrospector = new JaxbAnnotationIntrospector(
objectMapper.getTypeFactory());
objectMapper.setAnnotationIntrospectors(
createPair(objectMapper.getSerializationConfig(), jaxbAnnotationIntrospector),
createPair(objectMapper.getDeserializationConfig(), jaxbAnnotationIntrospector));
}
private AnnotationIntrospector createPair(MapperConfig config,
JaxbAnnotationIntrospector jaxbAnnotationIntrospector) {
return AnnotationIntrospector.pair(config.getAnnotationIntrospector(), jaxbAnnotationIntrospector);
}
}
private static final class ObjectMapperContextResolver implements ContextResolver {
private final ObjectMapper objectMapper;
private ObjectMapperContextResolver(ObjectMapper objectMapper) {
this.objectMapper = objectMapper;
}
@Override
public ObjectMapper getContext(Class type) {
return this.objectMapper;
}
}
}
}
在Springboot 原生的Autoconfig 中，可以看到他基本做了如下几件事情
- 注册 jersey ServletContainer同时把application path 作为此servlet的 url mapping
ServletRegistrationBean registration = new ServletRegistrationBean<>(
new ServletContainer(this.config), applicationPath.getUrlMapping());
- 用customizers 进行配置。实现了ResourceConfigCustomizer
从JerseyAutoConfiguration的实现可以看出，如果能再写另外一个Autoconfig，可以读多个application path ， 就可以支持多个application了。例如，再写一个Autoconfig 命名成MultipleApplicationJerseyAutoConfiguration 。在这样的情况下，出现了两个AutoConfiguration来处理ApplicationPath， 如何避免冲突？ 根据JerseyAutoConfiguration的定义， 只要不出现org.glassfish.jersey.server.ResourceConfig的bean就行了。
@Configuration(proxyBeanMethods = false)
@ConditionalOnClass({ SpringComponentProvider.class, ServletRegistration.class })
@ConditionalOnBean(type = "org.glassfish.jersey.server.ResourceConfig")
@ConditionalOnWebApplication(type = Type.SERVLET)
@AutoConfigureOrder(Ordered.HIGHEST_PRECEDENCE)
@AutoConfigureBefore(DispatcherServletAutoConfiguration.class)
@AutoConfigureAfter(JacksonAutoConfiguration.class)
@EnableConfigurationProperties(JerseyProperties.class)
public class JerseyAutoConfiguration implements ServletContextAware {
}
那么可以有如下实现
@Configuration
@ConditionalOnClass(name = { "org.glassfish.jersey.server.spring.SpringComponentProvider",
"javax.servlet.ServletRegistration" })
@ConditionalOnWebApplication
@AutoConfigureOrder(Ordered.HIGHEST_PRECEDENCE + 1)
@AutoConfigureBefore(DispatcherServletAutoConfiguration.class)
@EnableConfigurationProperties(JerseyProperties.class)
public class MultipleApplicationJerseyAutoConfiguration implements ServletContextInitializer {
private static final Logger logger = LoggerFactory.getLogger(GingerServerAutoConfig.class);
private final JerseyProperties jersey;
private final List jaxAppList;
private final ObjectProvider customizers;
public MultipleApplicationJerseyAutoConfiguration(JerseyProperties jersey, List config,
ObjectProvider customizers) {
if (config == null || config.isEmpty()) {
throw new IllegalArgumentException("Application can't be null!");
}
this.jersey = jersey;
this.jaxAppList = config;
this.customizers = customizers;
}
protected String findApplicationPath(ApplicationPath annotation) {
// Jersey doesn't like to be the default servlet, so map to /* as a fallback
if (annotation == null) {
return null;
}
String applicationPath = annotation.value();
if (!applicationPath.startsWith("/")) {
applicationPath = "/" + applicationPath;
}
if (!applicationPath.endsWith("/*")) {
if (applicationPath.endsWith("/")) {
applicationPath = applicationPath + "*";
} else {
applicationPath = applicationPath + "/*";
}
}
return applicationPath;
}
@Override
public void onStartup(ServletContext servletContext) throws ServletException {
setServletContext(servletContext);
}
protected void registerServletMapping(Application jaxrsApp, Dynamic servletReg) {
String mappingPath = findApplicationPath(AnnotationUtils.findAnnotation(jaxrsApp.getClass(), ApplicationPath.class));
if (mappingPath != null) {
if (logger.isInfoEnabled()) {
logger.info("Adding servlet with Path: " + mappingPath);
}
servletReg.addMapping(mappingPath);
}
}
@Bean
@ConditionalOnMissingBean
public FilterRegistrationBean gingerServerRequestContextFilter() {
FilterRegistrationBean registration = new FilterRegistrationBean();
registration.setFilter(new RequestContextFilter());
registration.setOrder(this.jersey.getFilter().getOrder() - 1);
registration.setName("requestContextFilter");
return registration;
}
private void setServletContext(ServletContext servletContext) {
for (Application jaxrsApp : jaxAppList) {
final ResourceConfig resourceConfig = ResourceConfig.forApplication(jaxrsApp);
customizers.orderedStream().forEach((customizer) -> customizer.customize(resourceConfig));
Dynamic servletReg = servletContext.addServlet(ClassUtils.getUserClass(jaxrsApp.getClass()).getName(),
new ServletContainer(resourceConfig));
if (servletReg != null) {
servletReg.setInitParameters(jersey.getInit());
servletReg.setInitParameter(CommonProperties.METAINF_SERVICES_LOOKUP_DISABLE, Boolean.TRUE.toString());
servletReg.setAsyncSupported(true);
registerServletMapping(jaxrsApp, servletReg);
}
}
}
}
- 实现了在tomcatStarter 启动的时候被调用
class TomcatStarter implements ServletContainerInitializer {
private static final Log logger = LogFactory.getLog(TomcatStarter.class);
private final ServletContextInitializer[] initializers;
private volatile Exception startUpException;
TomcatStarter(ServletContextInitializer[] initializers) {
this.initializers = initializers;
}
@Override
public void onStartup(Set> classes, ServletContext servletContext) throws ServletException {
try {
for (ServletContextInitializer initializer : this.initializers) {
initializer.onStartup(servletContext);
}
}
catch (Exception ex) {
this.startUpException = ex;
// Prevent Tomcat from logging and re-throwing when we know we can
// deal with it in the main thread, but log for information here.
if (logger.isErrorEnabled()) {
logger.error("Error starting Tomcat context. Exception: " + ex.getClass().getName() + ". Message: "
+ ex.getMessage());
}
}
}
Exception getStartUpException() {
return this.startUpException;
}
}
顺便提一下tomat 启动的调用链为
AbstractApplicationContext.onRefresh ->ServletWebServerApplicationContext.onRefresh->ServletWebServerApplicationContext.createWebServer->TomcatServletWebServerFactory.getWebServer->TomcatServletWebServerFactory.prepareContext
最后把这些initializer 注入进tomcat
TomcatStarter starter = new TomcatStarter(initializers);
- 实现了扫描多个appliction，来注册多个jersey servlet
private void setServletContext(ServletContext servletContext) {
for (Application jaxrsApp : jaxAppList) {
final ResourceConfig resourceConfig = ResourceConfig.forApplication(jaxrsApp);
customizers.orderedStream().forEach((customizer) -> customizer.customize(resourceConfig));
Dynamic servletReg = servletContext.addServlet(ClassUtils.getUserClass(jaxrsApp.getClass()).getName(),
new ServletContainer(resourceConfig));
if (servletReg != null) {
servletReg.setInitParameters(jersey.getInit());
servletReg.setInitParameter(CommonProperties.METAINF_SERVICES_LOOKUP_DISABLE, Boolean.TRUE.toString());
servletReg.setAsyncSupported(true);
registerServletMapping(jaxrsApp, servletReg);
}
}
}
}
根据上文的分析，application的注册就不能从org.glassfish.jersey.server.ResourceConfig来继承，而是从Application来继承（防止JerseyAutoConfiguration 也启动）下面是一个例子
@Configuration
@ApplicationPath("/samplesvc/v1")
public class SampleResourceConfig extends Application {
@Override
public Set> getClasses() {
Set> providers = new LinkedHashSet>();
providers.add(SampleResource1.class);
return providers;
}
}
@Configuration
@ApplicationPath("/samplesvc/v2")
public class SampleResourceConfig2 extends Application {
@Override
public Set> getClasses() {
Set> providers = new LinkedHashSet>();
providers.add(SampleResource2.class);
return providers;
}
}