14. SpringBoot MVC + 分页 + 拦截器

SpringBoot MVC

环境搭建

1. 在pom.xml添加spring-boot-starter-web

   
       org.springframework.boot
       spring-boot-starter-web
   
   

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. 编写Controller，使用@RequestMapping和@RestController

   @RestController
   public class BookService {
   
       @Autowired
       private BookDao bookDao;
   
       @RequestMapping(value="/book",method=RequestMethod.GET)
       public List 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. 编写Filter，解决Ajax调用跨域问题

   @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", "*");//设置允许哪些域名应用进行ajax访问
           httpResponse.setHeader("Access-Control-Allow-Methods", "GET,PUT,POST,DELETE");
           httpResponse.setHeader("Access-Control-Allow-Headers", "Content-Type");
           chain.doFilter(request, response);//调用后续serlvet
       }
   
       @Override
       public void init(FilterConfig arg0) throws ServletException {
           // TODO Auto-generated method stub
   
       }
   
   }
   

5. 配置Filter，使用@WebFilter和@ServletComponentScan

   @SpringBootApplication//开启扫描、自动配置、bean定义
   @MapperScan(basePackages={"cn.xdl.dao"})//开启扫描Mapper接口
   @ServletComponentScan//开启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，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。

 
  org.springframework.boot
  spring-boot-devtools

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

  com.github.pagehelper
  pagehelper-spring-boot-starter
  1.2.3

然后在调用查询代码之前执行PageHelper.startPage方法

Page page = PageHelper.startPage(p, 3);
//分页查询
List list = bookDao.findAll();
//获取总页数
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

   public class AjaxDomainInterceptor implements HandlerInterceptor{
   
       @Override
       public boolean preHandle(
           HttpServletRequest request, 
           HttpServletResponse response, Object handler)
               throws Exception {
           response.setHeader("Access-Control-Allow-Origin", "*");//设置允许哪些域名应用进行ajax访问
           response.setHeader("Access-Control-Allow-Methods", "GET,PUT,POST,DELETE");
           response.setHeader("Access-Control-Allow-Headers", "Content-Type");
           return true;
       }
   
       //...
   }
   

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

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