SpringBoot入門系列篇(八):SpringBoot中使用Interceptor
阿新 • • 發佈:2019-01-05
前情提要
之前的系列篇中介紹了在SpringBoot中使用過濾器,其實攔截器和過濾器從功能上來說,攔截器/過濾器所能實現的功能過濾器/攔截器都能夠實現。但是過濾器是java實現的,它需要依賴於Servlet容器,而攔截器是SprignMVC實現的一個機制,獨立於Servlet容器,而且能實現IOC容器中的各個bean。簡單的說:過濾器的urlPattern針對的是所有的請求,而攔截器的urlPattern針對的SpringMVC中的Controller控制器處理的請求,並不會攔截Servlet容器
使用Interceptor例項
使用Interceptor很簡單,分為三個步驟:
1.建立自定義的攔截器並實現HandlerInterceptor介面;
package org.springframework.demo.section;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* 一個簡單的Interceptor攔截器類
* @author chengxi
*/
public class MyInterceptor implements HandlerInterceptor {
@Override
public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o) throws Exception {
//只有返回true才會繼續向下執行,返回false取消當前請求
System.out.println("myinterc prehandler" );
return true;
}
@Override
public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {
System.out.println("myinterc posthandler");
}
@Override
public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {
System.out.println("myinterc aftercompletion");
}
}
2.建立一個java類繼承WebMvcConfiguraeAdapter並重寫addInterceptor方法,該類用來新增配置攔截器:
package org.springframework.demo.section;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
/**
* 繼承WebMvcConfigureAdapter繼承並重寫addInterceptor方法用於新增配置攔截器
* @author chengxi
*/
public class MyAdapter extends WebMvcConfigurerAdapter {
@Override
public void addInterceptors(InterceptorRegistry registry) {
//新增攔截器
registry.addInterceptor(new MyInterceptor())
.addPathPatterns("/**");
super.addInterceptors(registry);
}
}
3.然後我們需要編寫一個Controller控制類用於處理url請求,因為攔截器只能攔截SpringMVC的Controller控制器處理的請求:
package org.springframework.demo.section;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
/**
* 一個簡單的控制器測試類,主要用於測試Interceptor攔截器的使用
* @author chengxi
*/
@RestController
@RequestMapping("/inter")
public class InterController {
@RequestMapping("/test")
public void test(HttpServletResponse response) throws IOException {
response.getWriter().print("<h1>Hello interceptor test</h1>");
}
}