SpringBoot拦截器Filter的使用方法详解

前言：

最新Servlet 3.0拦截器的使用

1.pom.xml添加需要使用的依赖

 4.0.0
 top.ytheng
 springboot-demo
 0.0.1
 jar
 
 
    org.springframework.boot
    spring-boot-starter-parent
    2.0.5.RELEASE
     
  
  

  
    UTF-8
    UTF-8
    1.8
  

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

    
      org.springframework.boot
      spring-boot-starter-test
      test
    
    
    
      org.springframework.boot
      spring-boot-starter-thymeleaf
    
    
    
      org.springframework.boot
      spring-boot-devtools
      true
true
    
  

  
    
    myspringboot
    
      
 org.springframework.boot
 spring-boot-maven-plugin
      
      
 maven-compiler-plugin
 
   1.8
   1.8
 
      
    
  

2.添加Filter拦截器

package top.ytheng.demo.filter;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

//Servlet3.0特性
//urlPatterns:拦截的url地址
//filterName:拦截器名称
@WebFilter(urlPatterns="/api
  @Override
  public void init(FilterConfig filterConfig) throws ServletException {
    // TODO Auto-generated method stub
    System.out.println("filter init...");
  }
  
  
  @Override
  public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
      throws IOException, ServletException {
    // TODO Auto-generated method stub
    System.out.println("doFilter...");
    
    HttpServletRequest req = (HttpServletRequest)request;
    HttpServletResponse resp = (HttpServletResponse)response;
    
    String username = req.getParameter("username");
    if(username.equals("theng")) {
      chain.doFilter(request, response);
    } else {
      //重定向
      resp.sendRedirect("/filter.html");
      return;
    }
    
  }

  
  @Override
  public void destroy() {
    // TODO Auto-generated method stub
    System.out.println("filter destroy...");
  }
  
}

3.添加测试控制器

package top.ytheng.demo.controller;

import java.util.HashMap;
import java.util.Map;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/api/v1/filter")
public class FilterController {

  @RequestMapping("/test")
  public Object testFilter() {
    Map map = new HashMap<>();
    map.put("name", "theng");
    map.put("pwd", "123456");
    return map;
  }
}

4.添加启动类

package top.ytheng.demo;

import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.ServletComponentScan;

@SpringBootApplication //等于下面3个
//@SpringBootConfiguration
//@EnableAutoConfiguration
//@ComponentScan
//拦截器用到
@ServletComponentScan
public class DemoApplication {

  public static void main(String[] args) {
    SpringApplication.run(DemoApplication.class, args);
  }
  
}

5.添加拦截后调整的页面filter.html

  hello theng
  filter success

6.右键项目Run As启动项目，测试地址

http://localhost:8080/api/v1/filter/test?username=theng
http://localhost:8080/api/v1/filter/test?username=ytheng

另附：

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持考高分网。