SpringBoot MVC 攔截器

SpringBoot MVC

環境搭建

1. 在pom.xml添加spring-boot-starter-web

   <dependency>
       <groupId>org.springframework.boot</groupId>
       <artifactId>spring-boot-starter-web</artifactId>
   </dependency>
   

2. 修改application.yml配置

   
   spring:
    datasource:
     username: system
     password: 123456
     url: jdbc:oracle:thin:@localhost:1521:XE
     driverClassName: oracle.jdbc.OracleDriver
   server:
    port: 8889
   

3. 編寫Controller，使用@RequestMapping和@RestController

   @RestController
   public class BookService {
   
       @Autowired
       private BookDao bookDao;
   
       @RequestMapping(value="/book",method=RequestMethod.GET)
       public List<Book> loadAll(){
           return bookDao.findAll();
       }
   
       @RequestMapping(value="/book/{id}",method=RequestMethod.GET)
       public Book load(@PathVariable("id")int id){
           return bookDao.findById(id);
       }
   
       @RequestMapping(value="/book/{id}",method=RequestMethod.DELETE)
       public boolean delete(@PathVariable("id")int id){
           int row = bookDao.deleteById(id);
           if(row >= 1){
               return true;
           }else{
               return false;
           }
       }
   
       @RequestMapping(value="/book/{id}",method=RequestMethod.PUT)
       public boolean update(@PathVariable("id")int id, @RequestBody Book book){
           book.setId(id);
           int row = bookDao.update(book);
           if(row >= 1){
               return true;
           }else{
               return false;
           }
       }
   
       @RequestMapping(value="/book",method=RequestMethod.POST)
       public boolean add(@RequestBody Book book){
           bookDao.save(book);
           return true;
       }
   }
   

4. 編寫Filter，解決Ajax調用跨域問題

   @WebFilter(servletNames={"dispatcherServlet"})
   public class AjaxDomainFilter implements Filter{
   
       @Override
       public void destroy() {
           // TODO Auto-generated method stub
   
       }
   
       @Override
       public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
               throws IOException, ServletException {
           HttpServletResponse httpResponse = (HttpServletResponse)response;
           httpResponse.setHeader("Access-Control-Allow-Origin", "*");//設置允許哪些域名應用進行ajax訪問
           httpResponse.setHeader("Access-Control-Allow-Methods", "GET,PUT,POST,DELETE");
           httpResponse.setHeader("Access-Control-Allow-Headers", "Content-Type");
           chain.doFilter(request, response);//調用後續serlvet
       }
   
       @Override
       public void init(FilterConfig arg0) throws ServletException {
           // TODO Auto-generated method stub
   
       }
   
   }
   

5. 配置Filter，使用@WebFilter和@ServletComponentScan

   @SpringBootApplication//開啓掃描、自動配置、bean定義
   @MapperScan(basePackages={"cn.xdl.dao"})//開啓掃描Mapper接口
   @ServletComponentScan//開啓WebFilter、WebServlet、WebListener配置支持
   public class BootApplication {
   
       public static void main(String[] args){
           SpringApplication.run(BootApplication.class, args);
       }
   
   }
   

6. 修改pc_web前端的common.js，將請求路徑改爲

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

SpringBoot 熱啓動

當修改完畢程序代碼後，可以自動重新部署。

 <dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-devtools</artifactId>
</dependency>

如果修改了pom.xml定義，要從新啓動，修改了java代碼可以自動重新啓動。

SpringBoot MyBatis分頁

<dependency>
  <groupId>com.github.pagehelper</groupId>
  <artifactId>pagehelper-spring-boot-starter</artifactId>
  <version>1.2.3</version>
</dependency>

然後在調用查詢代碼之前執行PageHelper.startPage方法

Page page = PageHelper.startPage(p, 3);
//分頁查詢
List list = bookDao.findAll();
//獲取總頁數
int totalPage = page.getPages();

SpringBoot 攔截器

1. 編寫攔截器類，實現HandlerInterceptor接口，實現PreHandle、PostHandle、afterCompletion方法

   public class AjaxDomainInterceptor implements HandlerInterceptor{
   
       @Override
       public boolean preHandle(
           HttpServletRequest request, 
           HttpServletResponse response, Object handler)
               throws Exception {
           response.setHeader("Access-Control-Allow-Origin", "*");//設置允許哪些域名應用進行ajax訪問
           response.setHeader("Access-Control-Allow-Methods", "GET,PUT,POST,DELETE");
           response.setHeader("Access-Control-Allow-Headers", "Content-Type");
           return true;
       }
   
       //...
   }
   

2. 編寫配置類，繼承WebMvcConfigurerAdapter，重寫addInterceptors方法

   //@Configuration
   @Component
   public class InterceptorConfiguration extends WebMvcConfigurerAdapter{
   
       public void addInterceptors(InterceptorRegistry registry) {
           //配置攔截器
           AjaxDomainInterceptor ajaxDomain = new AjaxDomainInterceptor();
           registry.addInterceptor(ajaxDomain).addPathPatterns("/**");
       }
   
   }