案例-敏感词汇过滤

案例-敏感词汇过滤

需求：

1. 对day_06案例录入的数据进行敏感词汇过滤
2. 敏感词汇参考《敏感词汇.txt》
3. 如果敏感词汇 替换为***

分析：

1. 对request对象进行增强 增强获取参数相关方法
2. 放行 传递代理对象

拦截器代码

package com.bai.Filter;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.ArrayList;
import java.util.List;

@WebFilter("/*")

public class SensitivWordsFilter implements Filter {
    private List<String> list = new ArrayList<String>();//敏感词汇集合
    public void init(FilterConfig filterConfig) throws ServletException {
        try{
            //获取文件真实路径
            ServletContext servletContext = filterConfig.getServletContext();
            String realPath = servletContext.getRealPath("src\\敏感词汇.txt");
            //读取文件
            BufferedReader br = new BufferedReader(new FileReader(realPath));
            //将文件的每一行添加到list中
            String line=null;
            while ((line = br.readLine())!=null){
                list.add(line);
            }

            br.close();
            System.out.println(list);
        }catch(Exception e){
            e.printStackTrace();
        }
    }

    public void doFilter(final ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        ServletRequest proxy_lenovo = (ServletRequest) Proxy.newProxyInstance(servletRequest.getClass().getClassLoader(), servletRequest.getClass().getInterfaces(), new InvocationHandler() {
            public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
                //增强getParameter方法
                //判断是否是getParameter方法
                if (method.getName().equals("getParameter")){
                    //增强返回值
                    //获取返回值
                    String value = (String) method.invoke(servletRequest, args);
                    if (value!=null){
                        for (String str : list) {
                            if (value.contains(str)){
                                value=value.replaceAll(str,"***");
                            }
                        }
                    }
                    return value;
                }
                return method.invoke(servletRequest,args);
            }
        });
        //放行
        filterChain.doFilter(servletRequest,servletResponse);
    }

    public void destroy() {

    }
}