Filter - 过滤敏感词汇

 1 /**
 2  * 敏感词汇过滤器
 3  */
 4 @WebFilter("/*")
 5 public class SensitiveWordsFilter implements Filter {
 6 
 7 
 8     public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws ServletException, IOException {
 9         //1.创建代理对象，增强getParameter方法
10 
11         ServletRequest proxy_req = (ServletRequest) Proxy.newProxyInstance(req.getClass().getClassLoader(), req.getClass().getInterfaces(), new InvocationHandler() {
12             @Override
13             public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
14                 //增强getParameter方法
15                 //判断是否是getParameter方法
16                 if(method.getName().equals("getParameter")){
17                     //增强返回值
18                     //获取返回值
19                     String value = (String) method.invoke(req,args);
20                     if(value != null){
21                         for (String str : list) {
22                             if(value.contains(str)){
23                                 value = value.replaceAll(str,"***");
24                             }
25                         }
26                     }
27                     
28                     return  value;
29                 }
30 
31                 //判断方法名是否是 getParameterMap
32 
33                 //判断方法名是否是 getParameterValues
34 
35                 return method.invoke(req,args);
36             }
37         });
38 
39         //2.放行
40         chain.doFilter(proxy_req, resp);
41     }
42     private List<String> list = new ArrayList<String>();//敏感词汇集合
43     public void init(FilterConfig config) throws ServletException {
44 
45         try{
46             //1.获取文件真实路径
47             ServletContext servletContext = config.getServletContext();
48             String realPath = servletContext.getRealPath("/WEB-INF/classes/敏感词汇.txt");　　// 敏感词汇.txt在src目录下
49             //2.读取文件
50             BufferedReader br = new BufferedReader(new FileReader(realPath));
51             //3.将文件的每一行数据添加到list中
52             String line = null;
53             while((line = br.readLine())!=null){
54                 list.add(line);
55             }
56 
57             br.close();
58 
59             System.out.println(list);
60 
61         }catch (Exception e){
62             e.printStackTrace();
63         }
64 
65     }
66 
67     public void destroy() {
68     }
69 
70 }