Spring Boot利用JavaConfig配置模式以及“约定优于配置”理念，极大简化了基于Spring MVC的Web应用和REST服务开发。

• Servlet：
  

   1 package org.windwant.spring.servlet;
   2 
   3 import javax.servlet.Servlet;
   4 import javax.servlet.ServletConfig;
   5 import javax.servlet.ServletException;
   6 import javax.servlet.ServletRequest;
   7 import javax.servlet.ServletResponse;
   8 import javax.servlet.annotation.WebServlet;
   9 import java.io.IOException;
  10 
  11 /**
  12  * BootSevlet
  13  */
  14 @WebServlet("/web")
  15 public class BootSevlet implements Servlet {
  16 
  17     @Override
  18     public void init(ServletConfig config) throws ServletException {
  19         System.out.println("servlet init...");
  20     }
  21 
  22     @Override
  23     public ServletConfig getServletConfig() {
  24         return null;
  25     }
  26 
  27     @Override
  28     public void service(ServletRequest req, ServletResponse res) throws ServletException, IOException {
  29         System.out.println(req.getServerName());
  30         res.getWriter().write("got your message!");
  31     }
  32 
  33     @Override
  34     public String getServletInfo() {
  35         return null;
  36     }
  37 
  38     @Override
  39     public void destroy() {
  40         System.out.println("servlet destroy...");
  41     }
  42 }

• Service：
  

  1 package org.windwant.spring.service;
  2 
  3 /**
  4  * BootService.
  5  */
  6 public interface BootService {
  7     String hello(String name);
  8 }

   1 package org.windwant.spring.service.impl;
   2 
   3 import org.springframework.stereotype.Service;
   4 import org.windwant.spring.service.BootService;
   5 
   6 /**
   7  * BootServiceImpl
   8  */
   9 @Service
  10 public class BootServiceImpl implements BootService {
  11 
  12     @Override
  13     public String hello(String name){
  14         String message = "Hello " + name + ", welcome to my world!";
  15         System.out.println(message);
  16         return message;
  17     }
  18 }

   

• Listener：

   1 package org.windwant.spring.listener;
   2 
   3 import org.windwant.spring.BootMgr;
   4 
   5 import javax.servlet.ServletContextEvent;
   6 import javax.servlet.ServletContextListener;
   7 import javax.servlet.annotation.WebListener;
   8 
   9 /**
  10  * BootListener
  11  */
  12 @WebListener
  13 public class BootListener implements ServletContextListener {
  14 
  15     @Override
  16     public void contextInitialized(ServletContextEvent sce) {
  17         System.out.println("listener init... : " + BootMgr.increment());
  18     }
  19 
  20     @Override
  21     public void contextDestroyed(ServletContextEvent sce) {
  22         System.out.println("listener destroy... : " + BootMgr.decrement());
  23     }
  24 }

• Job：

•  1 package org.windwant.spring.job;
   2 
   3 import org.springframework.scheduling.annotation.Scheduled;
   4 import org.springframework.stereotype.Component;
   5 
   6 import java.text.SimpleDateFormat;
   7 import java.util.Date;
   8 
   9 /**
  10  * BootJob
  11  */
  12 @Component
  13 public class BootJob {
  14 
  15     private static final SimpleDateFormat dateFormat = new SimpleDateFormat("HH:mm:ss");
  16 
  17     @Scheduled(fixedRate = 1000)
  18     public void reportTime(){
  19         System.out.println("current time is: " +  dateFormat.format(new Date()));
  20     }
  21 }

• Interceptor：

•  1 package org.windwant.spring.interceptor;
   2 
   3 import org.springframework.web.servlet.HandlerInterceptor;
   4 import org.springframework.web.servlet.ModelAndView;
   5 
   6 import javax.servlet.http.HttpServletRequest;
   7 import javax.servlet.http.HttpServletResponse;
   8 
   9 /**
  10  * BootInterceptor
  11  */
  12 public class BootInterceptor implements HandlerInterceptor {
  13 
  14     @Override
  15     public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o) throws Exception {
  16         System.out.println("interceptor preHandle...");
  17         return true;
  18     }
  19 
  20     @Override
  21     public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {
  22         System.out.println("interceptor postHandle...");
  23     }
  24 
  25     @Override
  26     public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {
  27         System.out.println("interceptor over...");
  28     }
  29 }

   1 package org.windwant.spring.interceptor;
   2 
   3 import org.springframework.context.annotation.Configuration;
   4 import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
   5 import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
   6 
   7 /**
   8  * BootWebConfig
   9  */
  10 @Configuration
  11 public class BootWebConfig extends WebMvcConfigurerAdapter {
  12 
  13     @Override
  14     public void addInterceptors(InterceptorRegistry registry) {
  15         registry.addInterceptor(new BootInterceptor()).addPathPatterns("/**");
  16         super.addInterceptors(registry);
  17     }
  18 }

   

• Filter：

•  1 package org.windwant.spring.filter;
   2 
   3 import javax.servlet.Filter;
   4 import javax.servlet.FilterChain;
   5 import javax.servlet.FilterConfig;
   6 import javax.servlet.ServletException;
   7 import javax.servlet.ServletRequest;
   8 import javax.servlet.ServletResponse;
   9 import javax.servlet.annotation.WebFilter;
  10 import java.io.IOException;
  11 
  12 /**
  13  * BootFilter
  14  */
  15 @WebFilter
  16 public class BootFilter implements Filter {
  17 
  18     @Override
  19     public void init(FilterConfig filterConfig) throws ServletException {
  20         System.out.println("filter init...");
  21     }
  22 
  23     @Override
  24     public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
  25         System.out.println("filter...");
  26         filterChain.doFilter(servletRequest, servletResponse);
  27     }
  28 
  29     @Override
  30     public void destroy() {
  31         System.out.println("filter destroy...");
  32     }
  33 }

• BootSpring：

•  1 package org.windwant.spring;
   2 
   3 import org.joda.time.LocalTime;
   4 import org.springframework.beans.factory.annotation.Autowired;
   5 import org.springframework.boot.SpringApplication;
   6 import org.springframework.boot.autoconfigure.SpringBootApplication;
   7 import org.springframework.boot.web.servlet.ServletComponentScan;
   8 import org.springframework.scheduling.annotation.EnableScheduling;
   9 import org.springframework.web.bind.annotation.PathVariable;
  10 import org.springframework.web.bind.annotation.RequestMapping;
  11 import org.springframework.web.bind.annotation.RestController;
  12 import org.windwant.spring.service.BootService;
  13 
  14 /**
  15  * Hello world!
  16  * @RestController = @Controller + @ResponseBody
  17  * @SpringBootApplication = @Configration +  @EnableAutoConfiguration + @ComponentScan
  18  * @ServletComponentScan scan servlet filter interceptor listener
  19  */
  20 @RestController
  21 @SpringBootApplication
  22 @ServletComponentScan
  23 @EnableScheduling //定时任务
  24 public class BootSpring
  25 {
  26     @RequestMapping("/{name}")
  27     String home(@PathVariable String name){
  28         return bootService.hello(name);
  29     }
  30 
  31     @Autowired
  32     private BootService bootService;
  33 
  34     public static void main( String[] args )
  35     {
  36         LocalTime localTime = new LocalTime();
  37         System.out.println( "Hello World!" + localTime.toString());
  38         localTime = localTime.plusHours(1);
  39         System.out.println("Hello agin World!" + localTime.toString());
  40         SpringApplication.run(BootSpring.class, args);
  41 
  42     }
  43 }

   1 package org.windwant.spring;
   2 
   3 import java.util.concurrent.atomic.AtomicInteger;
   4 
   5 /**
   6  * BootMgr
   7  */
   8 public class BootMgr {
   9 
  10     private static AtomicInteger times = new AtomicInteger();
  11 
  12     public static Integer increment(){
  13         return times.incrementAndGet();
  14     }
  15 
  16     public static Integer decrement(){
  17         return times.decrementAndGet();
  18     }
  19 }

        项目地址：https://github.com/windwant/spring-boot-test

Spring boot 基于Spring MVC的Web应用和REST服务开发