Filter细节_过滤器拦截路径配置

Fitter-细节-过滤器拦截路径配置

1. 具体资源路径： /index.jsp 只有访问index.jsp资源时，过滤器才会被执行

2. 拦截目录： /user/* 访问/user下的所有资源时，过滤器都会被执行

3. 后缀名拦截： *.jsp 访问所有后缀名为jsp资源时，过滤器都会被执行

4. 拦截所有资源：/* 访问所有资源时，过滤器都会被执行

1. 具体资源路径： /index.jsp 只有访问index.jsp资源时，过滤器才会被执行

创建hello.jsp

<%@ page contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" %>
<!DOCTYPE html>
<html>
<head>
    <title>JSP - Hello World</title>
</head>
<body>
hello.jsp
</body>
</html>

创建过滤器

package com.example.day_19_fitterlistener.filter;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import java.io.IOException;

/**
 * 过滤器快速入门
 */

@WebFilter("/index.jsp")//1. 具体资源路径： /index.jsp 只有访问index.jsp资源时，过滤器才会被执行
public class FilterDemo4 implements Filter {


    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        Filter.super.init(filterConfig);
    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        System.out.println("FitterDemo4......");
    }

    @Override
    public void destroy() {
        Filter.super.destroy();
    }
}

我们运行代码，只有访问index.jsp的时候控制台才会输出FitterDemo4.....，访问hello.jsp的时候，控制台不会输出

2. 拦截目录： /user/* 访问/user下的所有资源时，过滤器都会被执行

创建FitterDemo4

package com.example.day_19_fitterlistener.filter;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import java.io.IOException;

/**
 * 过滤器快速入门
 */

//@WebFilter("/index.jsp")//1. 具体资源路径： /index.jsp 只有访问index.jsp资源时，过滤器才会被执行
@WebFilter("/user/*")//2. 拦截目录： /user/* 访问/user下的所有资源时，过滤器都会被执行
public class FilterDemo4 implements Filter {


    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        Filter.super.init(filterConfig);
    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        System.out.println("FitterDemo4......");
    }

    @Override
    public void destroy() {
        Filter.super.destroy();
    }
}

创建两个ServletDemo

package com.example.day_19_fitterlistener.servlet;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@WebServlet("/user/findAllServlet")
public class ServletDemo1 extends HttpServlet {
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        System.out.println("findAllServlet...");
        super.doPost(req, resp);
    }

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        super.doGet(req, resp);
    }
}

package com.example.day_19_fitterlistener.servlet;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@WebServlet("/user/updateServlet")
public class ServletDemo2 extends HttpServlet {
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        System.out.println("updateServlet...");
        super.doPost(req, resp);
    }

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        super.doGet(req, resp);
    }
}

3. 后缀名拦截： *.jsp 访问所有后缀名为jsp资源时，过滤器都会被执行

package com.example.day_19_fitterlistener.filter;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import java.io.IOException;

/**
 * 过滤器快速入门
 */

//@WebFilter("/index.jsp")//1. 具体资源路径： /index.jsp 只有访问index.jsp资源时，过滤器才会被执行
//@WebFilter("/user/*")//2. 拦截目录： /user/* 访问/user下的所有资源时，过滤器都会被执行
@WebFilter("*.jsp")//3. 后缀名拦截： *.jsp 访问所有后缀名为jsp资源时，过滤器都会被执行
public class FilterDemo4 implements Filter {


    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        Filter.super.init(filterConfig);
    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        System.out.println("FitterDemo4......");
    }

    @Override
    public void destroy() {
        Filter.super.destroy();
    }
}