SpringBoot MVC 攔截器

SpringBoot MVC

環境搭建

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. 編寫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. 編寫Filter，解決Ajax調用跨域問題

   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", "*");//設置允許哪些域名應用進行ajax訪問
   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); //調用后續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//開啟掃描、自動配置、bean定義
   2.  
      @MapperScan(basePackages={"cn.xdl.dao"})//開啟掃描Mapper接口
   3.  
      @ServletComponentScan//開啟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，將請求路徑改為

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

SpringBoot 熱啟動

當修改完畢程序代碼后，可以自動重新部署。

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

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

SpringBoot MyBatis分頁

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

然后在調用查詢代碼之前執行PageHelper.startPage方法

1.  
   Page page = PageHelper.startPage(p, 3);
2.  
   //分頁查詢
3.  
   List list = bookDao.findAll();
4.  
   //獲取總頁數
5.  
   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

   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", "*");//設置允許哪些域名應用進行ajax訪問
   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. 編寫配置類，繼承WebMvcConfigurerAdapter，重寫addInterceptors方法

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