SpringBoot MVC 拦截器

SpringBoot MVC

环境搭建

1. 在pom.xml添加spring-boot-starter-web

   1.  
      <dependency>
   2.  
      <groupId>org.springframework.boot</groupId>
   3.  
      <artifactId>spring-boot-starter-web</artifactId>
   4.  
      </dependency>

2. 修改application.yml配置

   1.  
       
   2.  
      spring:
   3.  
      datasource:
   4.  
      username: system
   5.  
      password: 123456
   6.  
      url: jdbc:oracle:thin:@localhost:1521:XE
   7.  
      driverClassName: oracle.jdbc.OracleDriver
   8.  
      server:
   9.  
      port: 8889

3. 编写Controller，使用@RequestMapping和@RestController

   1.  
      @RestController
   2.  
      public class BookService {
   3.  
       
   4.  
      @Autowired
   5.  
      private BookDao bookDao;
   6.  
       
   7.  
      @RequestMapping(value="/book",method=RequestMethod.GET)
   8.  
      public List<Book> loadAll(){
   9.  
      return bookDao.findAll();
   10.  
       }
   11.  
        
   12.  
       @RequestMapping(value="/book/{id}",method=RequestMethod.GET)
   13.  
       public Book load(@PathVariable("id")int id){
   14.  
       return bookDao.findById(id);
   15.  
       }
   16.  
        
   17.  
       @RequestMapping(value="/book/{id}",method=RequestMethod.DELETE)
   18.  
       public boolean delete(@PathVariable("id")int id){
   19.  
       int row = bookDao.deleteById(id);
   20.  
       if(row >= 1){
   21.  
       return true;
   22.  
       }else{
   23.  
       return false;
   24.  
       }
   25.  
       }
   26.  
        
   27.  
       @RequestMapping(value="/book/{id}",method=RequestMethod.PUT)
   28.  
       public boolean update(@PathVariable("id")int id, @RequestBody Book book){
   29.  
       book.setId(id);
   30.  
       int row = bookDao.update(book);
   31.  
       if(row >= 1){
   32.  
       return true;
   33.  
       }else{
   34.  
       return false;
   35.  
       }
   36.  
       }
   37.  
        
   38.  
       @RequestMapping(value="/book",method=RequestMethod.POST)
   39.  
       public boolean add(@RequestBody Book book){
   40.  
       bookDao.save(book);
   41.  
       return true;
   42.  
       }
   43.  
       }

4. 编写Filter，解决Ajax调用跨域问题

   1.  
      @WebFilter(servletNames={"dispatcherServlet"})
   2.  
      public class AjaxDomainFilter implements Filter{
   3.  
       
   4.  
      @Override
   5.  
      public void destroy() {
   6.  
      // TODO Auto-generated method stub
   7.  
       
   8.  
      }
   9.  
       
   10.  
       @Override
   11.  
       public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
   12.  
       throws IOException, ServletException {
   13.  
       HttpServletResponse httpResponse = (HttpServletResponse)response;
   14.  
       httpResponse.setHeader("Access-Control-Allow-Origin", "*");//设置允许哪些域名应用进行ajax访问
   15.  
       httpResponse.setHeader("Access-Control-Allow-Methods", "GET,PUT,POST,DELETE");
   16.  
       httpResponse.setHeader("Access-Control-Allow-Headers", "Content-Type");
   17.  
       chain.doFilter(request, response);//调用后续serlvet
   18.  
       }
   19.  
        
   20.  
       @Override
   21.  
       public void init(FilterConfig arg0) throws ServletException {
   22.  
       // TODO Auto-generated method stub
   23.  
        
   24.  
       }
   25.  
        
   26.  
       }

5. 配置Filter，使用@WebFilter和@ServletComponentScan

   1.  
      @SpringBootApplication//开启扫描、自动配置、bean定义
   2.  
      @MapperScan(basePackages={"cn.xdl.dao"})//开启扫描Mapper接口
   3.  
      @ServletComponentScan//开启WebFilter、WebServlet、WebListener配置支持
   4.  
      public class BootApplication {
   5.  
       
   6.  
      public static void main(String[] args){
   7.  
      SpringApplication.run(BootApplication.class, args);
   8.  
      }
   9.  
       
   10.  
       }

6. 修改pc_web前端的common.js，将请求路径改为

   var path = "http://localhost:8889";
   

SpringBoot 热启动

当修改完毕程序代码后，可以自动重新部署。

1.  
   <dependency>
2.  
   <groupId>org.springframework.boot</groupId>
3.  
   <artifactId>spring-boot-devtools</artifactId>
4.  
   </dependency>

如果修改了pom.xml定义，要从新启动，修改了java代码可以自动重新启动。

SpringBoot MyBatis分页

1.  
   <dependency>
2.  
   <groupId>com.github.pagehelper</groupId>
3.  
   <artifactId>pagehelper-spring-boot-starter</artifactId>
4.  
   <version>1.2.3</version>
5.  
   </dependency>

然后在调用查询代码之前执行PageHelper.startPage方法

1.  
   Page page = PageHelper.startPage(p, 3);
2.  
   //分页查询
3.  
   List list = bookDao.findAll();
4.  
   //获取总页数
5.  
   int totalPage = page.getPages();

SpringBoot 拦截器

1. 编写拦截器类，实现HandlerInterceptor接口，实现PreHandle、PostHandle、afterCompletion方法

   1.  
      public class AjaxDomainInterceptor implements HandlerInterceptor{
   2.  
       
   3.  
      @Override
   4.  
      public boolean preHandle(
   5.  
      HttpServletRequest request,
   6.  
      HttpServletResponse response, Object handler)
   7.  
      throws Exception {
   8.  
      response.setHeader("Access-Control-Allow-Origin", "*");//设置允许哪些域名应用进行ajax访问
   9.  
      response.setHeader("Access-Control-Allow-Methods", "GET,PUT,POST,DELETE");
   10.  
       response.setHeader("Access-Control-Allow-Headers", "Content-Type");
   11.  
       return true;
   12.  
       }
   13.  
        
   14.  
       //...
   15.  
       }

2. 编写配置类，继承WebMvcConfigurerAdapter，重写addInterceptors方法

   1.  
      //@Configuration
   2.  
      @Component
   3.  
      public class InterceptorConfiguration extends WebMvcConfigurerAdapter{
   4.  
       
   5.  
      public void addInterceptors(InterceptorRegistry registry) {
   6.  
      //配置拦截器
   7.  
      AjaxDomainInterceptor ajaxDomain = new AjaxDomainInterceptor();
   8.  
      registry.addInterceptor(ajaxDomain).addPathPatterns("/**");
   9.  
      }
   10.  
        
   11.  
       }