合肥最好的网站建设公司哪家好,免费注册网站网址,o2o服务平台,免费做网站模板在哪里做SpringBoot中注册四大组件 文章目录 SpringBoot中注册四大组件1. Servlet注册1. 基于配置类方式使用Servlet使用Servlet方式2. 基于纯注解方式配置Servlet 2. Filter(过滤器)注册1. 以配置类方式注册Filter2. 以纯注解方式注册Filter3. 以注解的方式注册Filter执行顺序不生效问…SpringBoot中注册四大组件 文章目录 SpringBoot中注册四大组件1. Servlet注册1. 基于配置类方式使用Servlet使用Servlet方式2. 基于纯注解方式配置Servlet 2. Filter(过滤器)注册1. 以配置类方式注册Filter2. 以纯注解方式注册Filter3. 以注解的方式注册Filter执行顺序不生效问题 3. Listener(监听器)注册1. Component注解2. EventListener注册监听3. 主启动配置监听 4. Interceptor(拦截器)注册5. 执行顺序 SpringBoot版本2.2.5 GA 版 GAGeneral Availability字面意思是 一般或正常可用性。 代表的是官方正式发布的版本推荐可广泛使用的版本国外有的软件用GA来表示RELEASE版本。 RELEASE表示正式发布版 parentgroupIdorg.springframework.boot/groupIdartifactIdspring-boot-starter-parent/artifactIdversion2.2.5.RELEASE/versionrelativePath/ !-- lookup parent from repository --/parent1. Servlet注册 有两种使用方式 1.基于配置类方式使用Servlet 2.基于纯注解方式使用Servlet 1. 基于配置类方式使用Servlet使用Servlet方式 自定义一个MyServlet类让其继承HttpServlet类 在配置类中使用ServletRegistrationBean类注册自定义MyServlet类 设置相关属性并访问 MyServlet
package com.yuan.demo.servlet;import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;public class MyServlet extends HttpServlet {Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {doPost(req, resp);}Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {String requestURI req.getRequestURI();System.out.println(requestURI requestURI);System.out.println(req.getRequestURL() req.getRequestURL());resp.getWriter().write(Hello,Servlet!!!);}
}
配置类
package com.yuan.demo.config;import com.yuan.demo.filter.MyFilter;
import com.yuan.demo.listener.MyListener;
import com.yuan.demo.servlet.MyServlet;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.boot.web.servlet.ServletListenerRegistrationBean;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;/**** 注册自定义的Servlet*/
Configuration
public class RegisterServerConfig {/*** 注册自定义Servlet* return*/Beanpublic ServletRegistrationBean myServlet(){ServletRegistrationBeanMyServlet registrationBean new ServletRegistrationBean(new MyServlet());registrationBean.addUrlMappings(/hello,/myServlet);return registrationBean;}/**** 注册自定义Filter* return*/Beanpublic FilterRegistrationBean myFilter(){FilterRegistrationBean filterRegistrationBean new FilterRegistrationBean();filterRegistrationBean.setFilter(new MyFilter());//设置自定义拦截器filterRegistrationBean.addUrlPatterns(/hello,/myServlet);//设置要拦截的请求return filterRegistrationBean;}/*** 注册自定义Listener* return*/Beanpublic ServletListenerRegistrationBean myListener(){ServletListenerRegistrationBeanMyListener registrationBean new ServletListenerRegistrationBean(new MyListener());return registrationBean;}
}
2. 基于纯注解方式配置Servlet 写一个继承HttpServlet的类,并在其上面加上**WebServlet**注解在SpringBoot的主启动类上加上**ServletComponentScan**注解 MyServletOne.java
package com.yuan.servlet;import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;WebServlet(value {/aa,/bb}) //配置请求路径其他参数看源码
public class MyServletOne extends HttpServlet {Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {doPost(req, resp);}Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {System.out.println(req.getRequestURI()req.getRequestURI());resp.getWriter().write(Hello,MyServletOne!!!);}
}SpringBoot主启动如下
package com.yuan;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.ServletComponentScan;ServletComponentScan
SpringBootApplication
public class MyServletApplication {public static void main(String[] args) {SpringApplication.run(MyServletApplication.class,args);}
}打开浏览器输入http://localhost:8080/aa输出结果如下
Hello,MyServletOne!!!2. Filter(过滤器)注册
1. 以配置类方式注册Filter 自定义一个Filter类(如:MyFilter.java)让其实现Filter接口并实现相关方法在配置类中注册 FilterRegistrationBean设置过滤的URL等编写测试案例进行过滤器测试 2. 以纯注解方式注册Filter 在在定义的Filter类中加入**WebFilter**注解并设置filterName及过滤的URL在主启动类上加入 ServletComponentScan注解启动服务器进行测试 3. 以注解的方式注册Filter执行顺序不生效问题 问题描述使用**WebFilter方式注入filter后用Order**注解指定filter的执行顺序则不起作用 原因分析 阅读源码发现重点在ServletComponentHandler 处理带有注解WebFilter的类handle方法中处理的attributes是WebFilter的属性因为WebFilter本身是没有Order属性所以构建的Filter将是默认的Order值而上面源码可得知类名可决定注册Filter的顺序即Filter过滤顺序因为此处只能注册默认的Order值 解决方法 以自定义的Filter名称(属性filterName“myFilter”)来改变其执行顺序 使用配置类的方式直接 对象.setOrder(2)来改变其顺序order值越小优先级越高
//根据MyFilter会在MyFilterOne执行后再执行
WebFilter(filterName bmyFilter,urlPatterns {/*,/one/*})
public class MyFilter implements Filter {.......
}
//MyFilterOne会被先执行
WebFilter(filterName amyFilter,urlPatterns {/*,/one/*})
public class MyFilterOne implements Filter {...}注SpringBoot自带初始化的Filter Spring Boot 自带的4中Filter主要为了了解其过滤顺序且与自定义Filter的执行顺序。由Order值从小到大的顺序由Filter类名来实现自定义Filter顺序因Order为默认值所以自带的4种Filter都会比自定义的Filter先执行。 org.springframework.boot.web.servlet.FilterRegistrationBean 258 - Mapping filter: characterEncodingFilter to: [/*]org.springframework.boot.web.servlet.FilterRegistrationBean 258 - Mapping filter: hiddenHttpMethodFilter to: [/*]org.springframework.boot.web.servlet.FilterRegistrationBean 258 - Mapping filter: httpPutFormContentFilter to: [/*]org.springframework.boot.web.servlet.FilterRegistrationBean 258 - Mapping filter: requestContextFilter to: [/*]
CharacterEncodingFilter :编码过滤器
/** 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* limitations under the License.*/package org.springframework.boot.web.servlet.filter;import org.springframework.core.Ordered;
import org.springframework.web.filter.CharacterEncodingFilter;/*** {link CharacterEncodingFilter} that also implements {link Ordered}.** author Phillip Webb* since 2.0.0*/
public class OrderedCharacterEncodingFilter extends CharacterEncodingFilter implements OrderedFilter {private int order Ordered.HIGHEST_PRECEDENCE; //HIGHEST_PRECEDENCE -2147483648;Overridepublic int getOrder() {return this.order;}/*** Set the order for this filter.* param order the order to set*/public void setOrder(int order) {this.order order;}
}
HiddenHttpMethodFilter :处理隐藏的PUT,DELETE等请求方法
/** 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* limitations under the License.*/package org.springframework.boot.web.reactive.filter;import org.springframework.core.Ordered;
import org.springframework.web.filter.reactive.HiddenHttpMethodFilter;/*** {link HiddenHttpMethodFilter} that also implements {link Ordered}.** author Artsiom Yudovin* since 2.0.5*/
public class OrderedHiddenHttpMethodFilter extends HiddenHttpMethodFilter implements OrderedWebFilter {/*** The default order is high to ensure the filter is applied before Spring Security.*/public static final int DEFAULT_ORDER REQUEST_WRAPPER_FILTER_MAX_ORDER - 10000;private int order DEFAULT_ORDER;Overridepublic int getOrder() {return this.order;}/*** Set the order for this filter.* param order the order to set*/public void setOrder(int order) {this.order order;}}
HttpPutFormContentFilter :处理PUT表单请求
/** Copyright 2002-2018 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* limitations under the License.*/package org.springframework.web.filter;import java.io.IOException;
import java.io.InputStream;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Enumeration;
import java.util.LinkedHashMap;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import javax.servlet.http.HttpServletResponse;import org.springframework.http.HttpInputMessage;
import org.springframework.http.MediaType;
import org.springframework.http.converter.FormHttpMessageConverter;
import org.springframework.http.converter.support.AllEncompassingFormHttpMessageConverter;
import org.springframework.http.server.ServletServerHttpRequest;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.util.MultiValueMap;
import org.springframework.util.StringUtils;/*** {link javax.servlet.Filter} that makes form encoded data available through* the {code ServletRequest.getParameter*()} family of methods during HTTP PUT* or PATCH requests.** pThe Servlet spec requires form data to be available for HTTP POST but* not for HTTP PUT or PATCH requests. This filter intercepts HTTP PUT and PATCH* requests where content type is {code application/x-www-form-urlencoded},* reads form encoded content from the body of the request, and wraps the ServletRequest* in order to make the form data available as request parameters just like* it is for HTTP POST requests.** author Rossen Stoyanchev* since 3.1* deprecated as of 5.1 in favor of {link FormContentFilter} which is the same* but also handles DELETE.*/
Deprecated
public class HttpPutFormContentFilter extends OncePerRequestFilter {private FormHttpMessageConverter formConverter new AllEncompassingFormHttpMessageConverter();/*** Set the converter to use for parsing form content.* pBy default this is an instance of {link AllEncompassingFormHttpMessageConverter}.*/public void setFormConverter(FormHttpMessageConverter converter) {Assert.notNull(converter, FormHttpMessageConverter is required.);this.formConverter converter;}public FormHttpMessageConverter getFormConverter() {return this.formConverter;}/*** The default character set to use for reading form data.* This is a shortcut for:br* {code getFormConverter.setCharset(charset)}.*/public void setCharset(Charset charset) {this.formConverter.setCharset(charset);}Overrideprotected void doFilterInternal(final HttpServletRequest request, HttpServletResponse response,FilterChain filterChain) throws ServletException, IOException {if ((PUT.equals(request.getMethod()) || PATCH.equals(request.getMethod())) isFormContentType(request)) {HttpInputMessage inputMessage new ServletServerHttpRequest(request) {Overridepublic InputStream getBody() throws IOException {return request.getInputStream();}};MultiValueMapString, String formParameters this.formConverter.read(null, inputMessage);if (!formParameters.isEmpty()) {HttpServletRequest wrapper new HttpPutFormContentRequestWrapper(request, formParameters);filterChain.doFilter(wrapper, response);return;}}filterChain.doFilter(request, response);}private boolean isFormContentType(HttpServletRequest request) {String contentType request.getContentType();if (contentType ! null) {try {MediaType mediaType MediaType.parseMediaType(contentType);return (MediaType.APPLICATION_FORM_URLENCODED.includes(mediaType));}catch (IllegalArgumentException ex) {return false;}}else {return false;}}private static class HttpPutFormContentRequestWrapper extends HttpServletRequestWrapper {private MultiValueMapString, String formParameters;public HttpPutFormContentRequestWrapper(HttpServletRequest request, MultiValueMapString, String parameters) {super(request);this.formParameters parameters;}OverrideNullablepublic String getParameter(String name) {String queryStringValue super.getParameter(name);String formValue this.formParameters.getFirst(name);return (queryStringValue ! null ? queryStringValue : formValue);}Overridepublic MapString, String[] getParameterMap() {MapString, String[] result new LinkedHashMap();EnumerationString names getParameterNames();while (names.hasMoreElements()) {String name names.nextElement();result.put(name, getParameterValues(name));}return result;}Overridepublic EnumerationString getParameterNames() {SetString names new LinkedHashSet();names.addAll(Collections.list(super.getParameterNames()));names.addAll(this.formParameters.keySet());return Collections.enumeration(names);}OverrideNullablepublic String[] getParameterValues(String name) {String[] parameterValues super.getParameterValues(name);ListString formParam this.formParameters.get(name);if (formParam null) {return parameterValues;}if (parameterValues null || getQueryString() null) {return StringUtils.toStringArray(formParam);}else {ListString result new ArrayList(parameterValues.length formParam.size());result.addAll(Arrays.asList(parameterValues));result.addAll(formParam);return StringUtils.toStringArray(result);}}}}
RequestContextFilter :设置请求的上下文环境
/** Copyright 2002-2015 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* limitations under the License.*/package org.springframework.web.filter;import java.io.IOException;import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;import org.springframework.context.i18n.LocaleContextHolder;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;/*** Servlet Filter that exposes the request to the current thread,* through both {link org.springframework.context.i18n.LocaleContextHolder} and* {link RequestContextHolder}. To be registered as filter in {code web.xml}.** pAlternatively, Springs {link org.springframework.web.context.request.RequestContextListener}* and Springs {link org.springframework.web.servlet.DispatcherServlet} also expose* the same request context to the current thread.** pThis filter is mainly for use with third-party servlets, e.g. the JSF FacesServlet.* Within Springs own web support, DispatcherServlets processing is perfectly sufficient.** author Juergen Hoeller* author Rod Johnson* author Rossen Stoyanchev* since 2.0* see org.springframework.context.i18n.LocaleContextHolder* see org.springframework.web.context.request.RequestContextHolder* see org.springframework.web.context.request.RequestContextListener* see org.springframework.web.servlet.DispatcherServlet*/
public class RequestContextFilter extends OncePerRequestFilter {private boolean threadContextInheritable false;/*** Set whether to expose the LocaleContext and RequestAttributes as inheritable* for child threads (using an {link java.lang.InheritableThreadLocal}).* pDefault is false, to avoid side effects on spawned background threads.* Switch this to true to enable inheritance for custom child threads which* are spawned during request processing and only used for this request* (that is, ending after their initial task, without reuse of the thread).* pbWARNING:/b Do not use inheritance for child threads if you are* accessing a thread pool which is configured to potentially add new threads* on demand (e.g. a JDK {link java.util.concurrent.ThreadPoolExecutor}),* since this will expose the inherited context to such a pooled thread.*/public void setThreadContextInheritable(boolean threadContextInheritable) {this.threadContextInheritable threadContextInheritable;}/*** Returns false so that the filter may set up the request context in each* asynchronously dispatched thread.*/Overrideprotected boolean shouldNotFilterAsyncDispatch() {return false;}/*** Returns false so that the filter may set up the request context in an* error dispatch.*/Overrideprotected boolean shouldNotFilterErrorDispatch() {return false;}Overrideprotected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain)throws ServletException, IOException {ServletRequestAttributes attributes new ServletRequestAttributes(request, response);initContextHolders(request, attributes);try {filterChain.doFilter(request, response);}finally {resetContextHolders();if (logger.isTraceEnabled()) {logger.trace(Cleared thread-bound request context: request);}attributes.requestCompleted();}}private void initContextHolders(HttpServletRequest request, ServletRequestAttributes requestAttributes) {LocaleContextHolder.setLocale(request.getLocale(), this.threadContextInheritable);RequestContextHolder.setRequestAttributes(requestAttributes, this.threadContextInheritable);if (logger.isTraceEnabled()) {logger.trace(Bound request context to thread: request);}}private void resetContextHolders() {LocaleContextHolder.resetLocaleContext();RequestContextHolder.resetRequestAttributes();}
}3. Listener(监听器)注册
1. Component注解 编写自定义监听类如RegListenerTwo实现ApplicationListener接口在自定义监听类上面标注 Component注解 package com.yuan.regcomponent;import org.springframework.context.ApplicationEvent;
import org.springframework.context.ApplicationListener;
import org.springframework.stereotype.Component;Component
public class RegListenerTwo implements ApplicationListener {Overridepublic void onApplicationEvent(ApplicationEvent event) {System.out.println(RegListenerTwo执行了);}
}
2. EventListener注册监听 编写自定义监听类如RegListenerTwo实现ApplicationListener接口在自定义监听类上面标注 Component注解在自定义类中编写一个监听方法并在方法上标注EventListener注解 package com.yuan.regcomponent;import org.springframework.context.ApplicationEvent;
import org.springframework.context.ApplicationListener;
import org.springframework.context.event.EventListener;
import org.springframework.stereotype.Component;Component
public class RegListenerThree {EventListenerpublic void onApplicationEvent(ApplicationEvent event) {System.out.println(RegListenerThree执行了);}
}
3. 主启动配置监听 编写自定义监听类如RegListenerOne实现ApplicationListener接口在主启动类上面标注ServletComponentScan将自定义的监听类加入到SpringApplication的监听中 编写监听类
package com.yuan.regcomponent;import org.springframework.context.ApplicationEvent;
import org.springframework.context.ApplicationListener;public class RegListenerOne implements ApplicationListener {Overridepublic void onApplicationEvent(ApplicationEvent event) {System.out.println(RegListenerOne执行了);}
}
直接启动类开启注解并添加自定义监听
package com.yuan;import com.yuan.regcomponent.RegListenerOne;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.ServletComponentScan;SpringBootApplication
ServletComponentScan
public class YuanBootDiskfileApplication {public static void main(String[] args) {//SpringApplication.run(YuanBootDiskfileApplication.class, args);SpringApplication springApplication new SpringApplication(YuanBootDiskfileApplication.class);springApplication.addListeners(new RegListenerOne());//添加自定义监听类springApplication.run(args);}}
4. Interceptor(拦截器)注册
自定义拦截器
package com.yuan.demo.interceptor;import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;/*** 自定义拦截器*/
public class MyInterceptor implements HandlerInterceptor {Overridepublic boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {System.out.println(MyInterceptor拦截器。。。。处理前);return true;}Overridepublic void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {StringBuffer requestURL request.getRequestURL();System.out.println(MyInterceptor拦截器拦截了请求requestURL);}Overridepublic void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {System.out.println(MyInterceptor拦截器。。。。处理后);}
}
注册拦截器
package com.yuan.demo.config;import com.yuan.demo.interceptor.MyInterceptor;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;Configuration
public class MyInterceptorConfig implements WebMvcConfigurer {Overridepublic void addInterceptors(InterceptorRegistry registry) {InterceptorRegistration interceptor registry.addInterceptor(new MyInterceptor());interceptor.addPathPatterns(/hello,/test);//拦截的urlinterceptor.excludePathPatterns(/login);//排除拦截的urlinterceptor.order(1);//拦截顺序}
}
5. 执行顺序 注意 监听器 、 过滤器、 拦截器 执行优先顺序如下 监听器 过滤器 拦截器 同时配置了Servlet过滤器拦截器优先顺序如下
ServletFilterInterceptor
