过滤器-过滤敏感词汇

首先要准备好敏感词库，敏感词汇的格式如下：

|1

买枪|2

四大舰队|3

其中1代表禁用词：禁用词将禁止提交，2代表审核次：将以高亮字体显示，3代表过滤词：将替换为****，

过滤器代码实现如下：

package cn.itcast.web.filter; import java.io.BufferedReader; import java.io.File; import java.io.FileReader; import java.io.IOException; import java.util.ArrayList; import java.util.Enumeration; import java.util.List; import java.util.regex.Matcher; import java.util.regex.Pattern; 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.http.HttpServletRequest; import javax.servlet.http.HttpServletRequestWrapper; import javax.servlet.http.HttpServletResponse; public class WordsFilter implements Filter { private List<String> banWords = new ArrayList(); //禁用词 private List<String> auditWords = new ArrayList(); //审核词 private List<String> replaceWords = new ArrayList(); //替换词 //初始化将敏感词库全部加载到集合中 public void init(FilterConfig filterConfig) throws ServletException { try{ String path = WordsFilter.class.getClassLoader().getResource("").getPath(); //得到类目录 File files[] = new File(path).listFiles(); //得到目录下的所有文件 for(File file : files){ //如果不是文件返回 if(!file.isFile()){ continue; } //如果不是txt文件返回 if(!file.getName().endsWith(".txt")){ continue; } //读txt文件 BufferedReader br = new BufferedReader(new FileReader(file)); String line = null; while((line=br.readLine())!=null){ String s[] = line.split("\\|"); if(s.length!=2){ continue; } String level = s[1].trim(); if("1".equals(level)){ banWords.add(s[0]); } if("2".equals(level)){ auditWords.add(s[0]); } if("3".equals(level)){ replaceWords.add(s[0]); } } } }catch (Exception e) { throw new RuntimeException(e); } } public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws IOException, ServletException { HttpServletRequest request = (HttpServletRequest) req; HttpServletResponse response = (HttpServletResponse) resp; //用户提交的数据是否包含禁用词 Enumeration e = request.getParameterNames(); while(e.hasMoreElements()){ String value = request.getParameter((String)e.nextElement()); for(String regex : banWords){ //正则表达式判断用户输入的内如是否存在 Pattern p = Pattern.compile(regex); Matcher m = p.matcher(value); if(m.find()){ request.setAttribute("message", "你发表的文章中含有非法词汇，你懂的！！"); request.getRequestDispatcher("/message.jsp").forward(request, response); return; } } } //用户提交的数据是否包含审核词和替换词，自定义包装类 Myrequest myrequest = new Myrequest(request); //放行 chain.doFilter(myrequest, response); } class Myrequest extends HttpServletRequestWrapper{ private HttpServletRequest request; public Myrequest(HttpServletRequest request){ super(request); this.request = request; } @Override public String getParameter(String name) { String value = this.request.getParameter(name); if(value==null){ return null; } //检查数据中是否包含审核词 for(String regex : auditWords){ Pattern p = Pattern.compile(regex); Matcher m = p.matcher(value); while(m.find()){ String word = m.group(); //得到找到的那个词 value = value.replaceAll(regex, "<font color='red'>" + word + "</font>"); } } //检查数据中是否包含替换词 for(String regex : replaceWords){ Pattern p = Pattern.compile(regex); Matcher m = p.matcher(value); while(m.find()){ value = value.replaceAll(regex, "****"); } } return value; } } public void destroy() { // TODO Auto-generated method stub } }