java配置多个过滤器优先级以及几个常用过滤器

向右看齐 2022-04-11 09:58 572阅读 0赞

一个项目中不出意外的话会有两个以上的过滤器，但是直接不配置的话他会按照你的过滤器名字排序执行，这样的话可能会导致一些性能上或者逻辑上的问题。那么，控制一下执行顺序是我们所必须要做的。

java封装了一个FilterRegistrationBean对象，可以把他比作一个容器，将过滤器套入这个对象中，可以对这个对象进行优先级设置、过滤规则设置等属性，下面是几个常用的过滤器以及过滤器配置。

**过滤器配置：**

package cn.ask.filter;
    
    import javax.servlet.DispatcherType;
    
    import org.springframework.boot.web.servlet.FilterRegistrationBean;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.web.filter.DelegatingFilterProxy;
    
    
    /**
     * Title:      FilterConfig
     * @date       2018年10月25日
     * @version    V1.0
     * Description: 过滤器配置
     */
    @SuppressWarnings("all")
    @Configuration
    public class FilterConfig {
    	/**
    	 * @Description 防xss攻击过滤器
    	 * @date 2018年8月16日下午4:55:44
    	 */
    	@Bean
    	public FilterRegistrationBean xssFilterRegistration() {
    		FilterRegistrationBean registration = new FilterRegistrationBean();
    		registration.setDispatcherTypes(DispatcherType.REQUEST);
    		registration.setFilter(new XssFilter());
    		registration.addUrlPatterns("/*");
    		registration.setName("xssFilter");
            //order数字越小越先执行
    		registration.setOrder(1);
    		return registration;
    	}
    	
    	/**  
    	* @Description 获取登录信息 
    	* @date 2018年10月25日上午9:14:48
    	*/
    	@Bean
    	public FilterRegistrationBean cookieRegistration() {
    		FilterRegistrationBean registration = new FilterRegistrationBean();
    		registration.setDispatcherTypes(DispatcherType.REQUEST);
    		registration.setFilter(new CookieFilter());
    		registration.addUrlPatterns("/*");
    		registration.setName("firstFilter");
    		registration.setOrder(2);
    		return registration;
    	}
    	
    }

**常用过滤器之一**：sso单点登录（使用cookie记录跨站数据）

package cn.ask.filter;
 
 import java.io.IOException;
 import java.net.URLDecoder;
 
 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.Cookie;
 import javax.servlet.http.HttpServletRequest;
 
 import org.apache.commons.lang3.StringUtils;
 
 /**
 * Servlet Filter implementation class FirstFilter
 */
 public class CookieFilter implements Filter {
 
 /**
 * Default constructor. 
 */
 public CookieFilter() {
 // TODO Auto-generated constructor stub
 }
 
 	/**
 	 * @see Filter#destroy()
 	 */
 	public void destroy() {
 		// TODO Auto-generated method stub
 	}
 
 	/**
 	 * @see Filter#doFilter(ServletRequest, ServletResponse, FilterChain)
 	 */
 	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
 		HttpServletRequest req = (HttpServletRequest) request;
 		String tokenHeader = req.getHeader("token");
 		if(StringUtils.isBlank(tokenHeader)) {
 			Cookie[] cookies = req.getCookies();
 			if (cookies != null && cookies.length > 0) {
 				for (int i = 0; i < cookies.length; i++) {
 					String name = cookies[i].getName();
 					String value = cookies[i].getValue();
 					if ("user_accesstoken".equals(name)) { // 用户token
 						req.setAttribute("token", URLDecoder.decode(value, "utf-8"));
 					}
 					if ("user_avatar".equals(name)) { // 头像
 						req.setAttribute("avatar", URLDecoder.decode(value, "utf-8"));
 					}
 					if ("user_nickname".equals(name)) { // 昵称
 						req.setAttribute("nickname", URLDecoder.decode(value, "utf-8"));
 					}
 					String token = (String) req.getAttribute("token");
 					if (StringUtils.isBlank(token)) {
 						req.setAttribute("isLogin", "no");
 					} else {
 						req.setAttribute("isLogin", "yes");
 					}
 				}
 			}else {
 				req.removeAttribute("token");
 				req.removeAttribute("avatar");
 				req.removeAttribute("nickname");
 				req.setAttribute("isLogin", "no");
 			}
 		} else {
 			req.setAttribute("token", tokenHeader);
 		}
 		
 		chain.doFilter(request, response);
 	}
 
 	/**
 	 * @see Filter#init(FilterConfig)
 	 */
 	public void init(FilterConfig fConfig) throws ServletException {
 		// TODO Auto-generated method stub
 	}
 
 }

**常用过滤器之二**：xss过滤以及防html注入过滤（包括过滤敏感词）

package cn.ask.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.http.HttpServletRequest;
    
    
    /**
     * Title:      XssFilter
     * @date       2018年8月16日
     * @version    V1.0
     * Description: xss过滤
     */
    public class XssFilter implements Filter {
    
    	@Override
    	public void init(FilterConfig config) throws ServletException {
    	}
    
    	@Override
    	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
                throws IOException, ServletException {
    		XssHttpServletRequestWrapper xssRequest = new XssHttpServletRequestWrapper((HttpServletRequest) request);
    		chain.doFilter(xssRequest, response);
    	}
    
    	@Override
    	public void destroy() {
    	}
    
    }

package cn.ask.filter;
 
 import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.util.LinkedHashMap;
 import java.util.Map;
 
 import javax.servlet.ReadListener;
 import javax.servlet.ServletInputStream;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletRequestWrapper;
 
 import org.apache.commons.io.IOUtils;
 import org.apache.commons.lang3.StringUtils;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.MediaType;
 
 
 /**
 * Title: XssHttpServletRequestWrapper
 * @date 2018年8月16日
 * @version V1.0
 * Description: XSS过滤处理
 */
 public class XssHttpServletRequestWrapper extends HttpServletRequestWrapper {
 /**没被包装过的HttpServletRequest（特殊场景，需要自己过滤*/
 HttpServletRequest orgRequest;
 /**html过滤*/
 private final static HtmlFilter HTMLFILTER = new HtmlFilter();
 
 public XssHttpServletRequestWrapper(HttpServletRequest request) {
 super(request);
 orgRequest = request;
 }
 
 @Override
 public ServletInputStream getInputStream() throws IOException {
 //非json类型，直接返回
 if(!super.getHeader(HttpHeaders.CONTENT_TYPE).equalsIgnoreCase(MediaType.APPLICATION_JSON_VALUE)){
 return super.getInputStream();
 }
 
 //为空，直接返回
 String json = IOUtils.toString(super.getInputStream(), "utf-8");
 if (StringUtils.isBlank(json)) {
 return super.getInputStream();
 }
 
 //xss过滤
 json = xssEncode(json);
 final ByteArrayInputStream bis = new ByteArrayInputStream(json.getBytes());
 return new ServletInputStream() {
 @Override
 public boolean isFinished() {
 return true;
 }
 
 @Override
 public boolean isReady() {
 return true;
 }
 
 @Override
 public void setReadListener(ReadListener readListener) {
 
 }
 
 @Override
 public int read() throws IOException {
 return bis.read();
 }
 };
 }
 
 @Override
 public String getParameter(String name) {
 String value = super.getParameter(xssEncode(name));
 if (StringUtils.isNotBlank(value)) {
 value = xssEncode(value);
 }
 return value;
 }
 
 @Override
 public String[] getParameterValues(String name) {
 String[] parameters = super.getParameterValues(name);
 if (parameters == null || parameters.length == 0) {
 return null;
 }
 
 for (int i = 0; i < parameters.length; i++) {
 parameters[i] = xssEncode(parameters[i]);
 }
 return parameters;
 }
 
 @Override
 public Map<String,String[]> getParameterMap() {
 Map<String,String[]> map = new LinkedHashMap<>();
 Map<String,String[]> parameters = super.getParameterMap();
 for (String key : parameters.keySet()) {
 String[] values = parameters.get(key);
 for (int i = 0; i < values.length; i++) {
 values[i] = xssEncode(values[i]);
 }
 map.put(key, values);
 }
 return map;
 }
 
 @Override
 public String getHeader(String name) {
 String value = super.getHeader(xssEncode(name));
 if (StringUtils.isNotBlank(value)) {
 value = xssEncode(value);
 }
 return value;
 }
 //富文本内容放行
 private String xssEncode(String input) {
 	if(!input.startsWith("<p")&&!input.startsWith("<ol")&&!input.startsWith("<ul")&&!input.startsWith("<hr/>")) {
 		input=HTMLFILTER.filter(input);
 	}
 //敏感词过滤
 input=SensitiveWordUtils.getSensitiveWordUtils().replaceSensitiveWord(input, '*', 2);
 return input;
 
 }
 
 /**
 * 获取最原始的request
 */
 public HttpServletRequest getOrgRequest() {
 return orgRequest;
 }
 
 /**
 * 获取最原始的request
 */
 public static HttpServletRequest getOrgRequest(HttpServletRequest request) {
 if (request instanceof XssHttpServletRequestWrapper) {
 return ((XssHttpServletRequestWrapper) request).getOrgRequest();
 }
 
 return request;
 }
 
 }

package cn.ask.filter;
 
 import java.util.*;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 import java.util.logging.Logger;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
 /**
 * Title: HTMLFilter
 * @date 2018年8月16日
 * @version V1.0
 * Description: 防html注入
 */
 public final class HtmlFilter {
 
 /** regex flag union representing /si modifiers in php **/
 private static final int REGEX_FLAGS_SI = Pattern.CASE_INSENSITIVE | Pattern.DOTALL;
 private static final Pattern P_COMMENTS = Pattern.compile("", Pattern.DOTALL);
 private static final Pattern P_COMMENT = Pattern.compile("^!--(.*)--$", REGEX_FLAGS_SI);
 private static final Pattern P_TAGS = Pattern.compile("<(.*?)>", Pattern.DOTALL);
 private static final Pattern P_END_TAG = Pattern.compile("^/([a-z0-9]+)", REGEX_FLAGS_SI);
 private static final Pattern P_START_TAG = Pattern.compile("^([a-z0-9]+)(.*?)(/?)$", REGEX_FLAGS_SI);
 private static final Pattern P_QUOTED_ATTRIBUTES = Pattern.compile("([a-z0-9]+)=([\"'])(.*?)\\2", REGEX_FLAGS_SI);
 private static final Pattern P_UNQUOTED_ATTRIBUTES = Pattern.compile("([a-z0-9]+)(=)([^\"\\s']+)", REGEX_FLAGS_SI);
 private static final Pattern P_PROTOCOL = Pattern.compile("^([^:]+):", REGEX_FLAGS_SI);
 private static final Pattern P_ENTITY = Pattern.compile("&#(\\d+);?");
 private static final Pattern P_ENTITY_UNICODE = Pattern.compile("&#x([0-9a-f]+);?");
 private static final Pattern P_ENCODE = Pattern.compile("%([0-9a-f]{2});?");
 private static final Pattern P_VALID_ENTITIES = Pattern.compile("&([^&;]*)(?=(;|&|$))");
 private static final Pattern P_VALID_QUOTES = Pattern.compile("(>|^)([^<]+?)(<|$)", Pattern.DOTALL);
 private static final Pattern P_END_ARROW = Pattern.compile("^>");
 private static final Pattern P_BODY_TO_END = Pattern.compile("<([^>]*?)(?=<|$)");
 private static final Pattern P_XML_CONTENT = Pattern.compile("(^|>)([^<]*?)(?=>)");
 private static final Pattern P_STRAY_LEFT_ARROW = Pattern.compile("<([^>]*?)(?=<|$)");
 private static final Pattern P_STRAY_RIGHT_ARROW = Pattern.compile("(^|>)([^<]*?)(?=>)");
 private static final Pattern P_AMP = Pattern.compile("&");
 private static final Pattern P_QUOTE = Pattern.compile("<");
 private static final Pattern P_LEFT_ARROW = Pattern.compile("<");
 private static final Pattern P_RIGHT_ARROW = Pattern.compile(">");
 private static final Pattern P_BOTH_ARROWS = Pattern.compile("<>");
 private static final String SS="#//";
 
 /** @xxx could grow large... maybe use sesat's ReferenceMap */
 private static final ConcurrentMap<String,Pattern> P_REMOVE_PAIR_BLANKS = new ConcurrentHashMap<String, Pattern>();
 private static final ConcurrentMap<String,Pattern> P_REMOVE_SELF_BLANKS = new ConcurrentHashMap<String, Pattern>();
 
 /** set of allowed html elements, along with allowed attributes for each element **/
 private final Map<String, List<String>> vAllowed;
 /** counts of open tags for each (allowable) html element **/
 private final Map<String, Integer> vTagCounts = new HashMap<String, Integer>();
 
 /** html elements which must always be self-closing (e.g. "<img />") **/
 private final String[] vSelfClosingTags;
 /** html elements which must always have separate opening and closing tags (e.g. "") **/
 private final String[] vNeedClosingTags;
 /** set of disallowed html elements **/
 private final String[] vDisallowed;
 /** attributes which should be checked for valid protocols **/
 private final String[] vProtocolAtts;
 /** allowed protocols **/
 private final String[] vAllowedProtocols;
 /** tags which should be removed if they contain no content (e.g. "" or "") **/
 private final String[] vRemoveBlanks;
 /** entities allowed within html markup **/
 private final String[] vAllowedEntities;
 /** flag determining whether comments are allowed in input String. */
 private final boolean stripComment;
 private final boolean encodeQuotes;
 private boolean vDebug = false;
 /**
 * flag determining whether to try to make tags when presented with "unbalanced"
 * angle brackets (e.g. "" becomes " text "). If set to false,
 * unbalanced angle brackets will be html escaped.
 */
 private final boolean alwaysMakeTags;
 
 /** Default constructor.
 *
 */
 public HtmlFilter() {
 vAllowed = new HashMap<>();
 
 final ArrayList<String> aAtts = new ArrayList<String>();
 aAtts.add("href");
 aAtts.add("target");
 vAllowed.put("a", aAtts);
 
 final ArrayList<String> imgAtts = new ArrayList<String>();
 imgAtts.add("src");
 imgAtts.add("width");
 imgAtts.add("height");
 imgAtts.add("alt");
 vAllowed.put("img", imgAtts);
 
 final ArrayList<String> noAtts = new ArrayList<String>();
 vAllowed.put("b", noAtts);
 vAllowed.put("strong", noAtts);
 vAllowed.put("i", noAtts);
 vAllowed.put("em", noAtts);
 
 vSelfClosingTags = new String[]{"img"};
 vNeedClosingTags = new String[]{"a", "b", "strong", "i", "em"};
 vDisallowed = new String[]{};
 /**no ftp*/
 vAllowedProtocols = new String[]{"http", "mailto", "https"};
 vProtocolAtts = new String[]{"src", "href"};
 vRemoveBlanks = new String[]{"a", "b", "strong", "i", "em"};
 vAllowedEntities = new String[]{"amp", "gt", "lt", "quot"};
 stripComment = true;
 encodeQuotes = true;
 alwaysMakeTags = true;
 }
 
 /** Set debug flag to true. Otherwise use default settings. See the default constructor.
 *
 * @param debug turn debug on with a true argument
 */
 public HtmlFilter(final boolean debug) {
 this();
 vDebug = debug;
 
 }
 
 /** Map-parameter configurable constructor.
 *
 * @param conf map containing configuration. keys match field names.
 */
 @SuppressWarnings("unchecked")
 	public HtmlFilter(final Map<String,Object> conf) {
 
 assert conf.containsKey("vAllowed") : "configuration requires vAllowed";
 assert conf.containsKey("vSelfClosingTags") : "configuration requires vSelfClosingTags";
 assert conf.containsKey("vNeedClosingTags") : "configuration requires vNeedClosingTags";
 assert conf.containsKey("vDisallowed") : "configuration requires vDisallowed";
 assert conf.containsKey("vAllowedProtocols") : "configuration requires vAllowedProtocols";
 assert conf.containsKey("vProtocolAtts") : "configuration requires vProtocolAtts";
 assert conf.containsKey("vRemoveBlanks") : "configuration requires vRemoveBlanks";
 assert conf.containsKey("vAllowedEntities") : "configuration requires vAllowedEntities";
 
 vAllowed = Collections.unmodifiableMap((HashMap<String, List<String>>) conf.get("vAllowed"));
 vSelfClosingTags = (String[]) conf.get("vSelfClosingTags");
 vNeedClosingTags = (String[]) conf.get("vNeedClosingTags");
 vDisallowed = (String[]) conf.get("vDisallowed");
 vAllowedProtocols = (String[]) conf.get("vAllowedProtocols");
 vProtocolAtts = (String[]) conf.get("vProtocolAtts");
 vRemoveBlanks = (String[]) conf.get("vRemoveBlanks");
 vAllowedEntities = (String[]) conf.get("vAllowedEntities");
 stripComment = conf.containsKey("stripComment") ? (Boolean) conf.get("stripComment") : true;
 encodeQuotes = conf.containsKey("encodeQuotes") ? (Boolean) conf.get("encodeQuotes") : true;
 alwaysMakeTags = conf.containsKey("alwaysMakeTags") ? (Boolean) conf.get("alwaysMakeTags") : true;
 }
 
 private void reset() {
 vTagCounts.clear();
 }
 
 private void debug(final String msg) {
 if (vDebug) {
 Logger.getAnonymousLogger().info(msg);
 }
 }
 
 //---------------------------------------------------------------
 /**my versions of some PHP library functions*/
 public static String chr(final int decimal) {
 return String.valueOf((char) decimal);
 }
 
 public static String htmlSpecialChars(final String s) {
 String result = s;
 result = regexReplace(P_AMP, "&", result);
 result = regexReplace(P_QUOTE, """, result);
 result = regexReplace(P_LEFT_ARROW, "<", result);
 result = regexReplace(P_RIGHT_ARROW, ">", result);
 return result;
 }
 
 //---------------------------------------------------------------
 /**
 * given a user submitted input String, filter out any invalid or restricted
 * html.
 *
 * @param input text (i.e. submitted by a user) than may contain html
 * @return "clean" version of input, with only valid, whitelisted html elements allowed
 */
 public String filter(final String input) {
 reset();
 String s = input;
 
 debug("************************************************");
 debug(" INPUT: " + input);
 
 s = escapeComments(s);
 debug(" escapeComments: " + s);
 
 s = balanceHTML(s);
 debug(" balanceHTML: " + s);
 
 s = checkTags(s);
 debug(" checkTags: " + s);
 
 s = processRemoveBlanks(s);
 debug("processRemoveBlanks: " + s);
 
 s = validateEntities(s);
 debug(" validateEntites: " + s);
 
 debug("************************************************\n\n");
 return s;
 }
 
 public boolean isAlwaysMakeTags(){
 return alwaysMakeTags;
 }
 
 public boolean isStripComments(){
 return stripComment;
 }
 
 private String escapeComments(final String s) {
 final Matcher m = P_COMMENTS.matcher(s);
 final StringBuffer buf = new StringBuffer();
 if (m.find()) {
 	/**(.*?)*/
 final String match = m.group(1); 
 m.appendReplacement(buf, Matcher.quoteReplacement(""));
 }
 m.appendTail(buf);
 
 return buf.toString();
 }
 
 private String balanceHTML(String s) {
 if (alwaysMakeTags) {
 //
 // try and form html
 //
 s = regexReplace(P_END_ARROW, "", s);
 s = regexReplace(P_BODY_TO_END, "<$1>", s);
 s = regexReplace(P_XML_CONTENT, "$1<$2", s);
 
 } else {
 //
 // escape stray brackets
 //
 s = regexReplace(P_STRAY_LEFT_ARROW, "<$1", s);
 s = regexReplace(P_STRAY_RIGHT_ARROW, "$1$2><", s);
 
 //
 // the last regexp causes '<>' entities to appear
 // (we need to do a lookahead assertion so that the last bracket can
 // be used in the next pass of the regexp)
 //
 s = regexReplace(P_BOTH_ARROWS, "", s);
 }
 
 return s;
 }
 
 private String checkTags(String s) {
 Matcher m = P_TAGS.matcher(s);
 
 final StringBuffer buf = new StringBuffer();
 while (m.find()) {
 String replaceStr = m.group(1);
 replaceStr = processTag(replaceStr);
 m.appendReplacement(buf, Matcher.quoteReplacement(replaceStr));
 }
 m.appendTail(buf);
 
 s = buf.toString();
 
 // these get tallied in processTag
 // (remember to reset before subsequent calls to filter method)
 for (String key : vTagCounts.keySet()) {
 for (int ii = 0; ii < vTagCounts.get(key); ii++) {
 s += "</" + key + ">";
 }
 }
 
 return s;
 }
 
 private String processRemoveBlanks(final String s) {
 String result = s;
 for (String tag : vRemoveBlanks) {
 if(!P_REMOVE_PAIR_BLANKS.containsKey(tag)){
 P_REMOVE_PAIR_BLANKS.putIfAbsent(tag, Pattern.compile("<" + tag + "(\\s[^>]*)?></" + tag + ">"));
 }
 result = regexReplace(P_REMOVE_PAIR_BLANKS.get(tag), "", result);
 if(!P_REMOVE_SELF_BLANKS.containsKey(tag)){
 P_REMOVE_SELF_BLANKS.putIfAbsent(tag, Pattern.compile("<" + tag + "(\\s[^>]*)?/>"));
 }
 result = regexReplace(P_REMOVE_SELF_BLANKS.get(tag), "", result);
 }
 
 return result;
 }
 
 private static String regexReplace(final Pattern regexPattern, final String replacement, final String s) {
 Matcher m = regexPattern.matcher(s);
 return m.replaceAll(replacement);
 }
 
 private String processTag(final String s) {
 // ending tags
 Matcher m = P_END_TAG.matcher(s);
 if (m.find()) {
 final String name = m.group(1).toLowerCase();
 if (allowed(name)) {
 if (!inArray(name, vSelfClosingTags)) {
 if (vTagCounts.containsKey(name)) {
 vTagCounts.put(name, vTagCounts.get(name) - 1);
 return "</" + name + ">";
 }
 }
 }
 }
 // starting tags
 m = P_START_TAG.matcher(s);
 if (m.find()) {
 final String name = m.group(1).toLowerCase();
 final String body = m.group(2);
 String ending = m.group(3);
 //debug( "in a starting tag, name='" + name + "'; body='" + body + "'; ending='" + ending + "'" );
 if (allowed(name)) {
 String params = "";
 final Matcher m2 = P_QUOTED_ATTRIBUTES.matcher(body);
 final Matcher m3 = P_UNQUOTED_ATTRIBUTES.matcher(body);
 final List<String> paramNames = new ArrayList<String>();
 final List<String> paramValues = new ArrayList<String>();
 while (m2.find()) {
 	/**([a-z0-9]+)*/
 paramNames.add(m2.group(1)); 
 /**(.*?)*/
 paramValues.add(m2.group(3)); 
 }
 while (m3.find()) {
 	/**([a-z0-9]+)*/
 paramNames.add(m3.group(1));
 /**([^\"\\s']+)*/
 paramValues.add(m3.group(3)); 
 }
 String paramName, paramValue;
 for (int ii = 0; ii < paramNames.size(); ii++) {
 paramName = paramNames.get(ii).toLowerCase();
 paramValue = paramValues.get(ii);
 if (allowedAttribute(name, paramName)) {
 if (inArray(paramName, vProtocolAtts)) {
 paramValue = processParamProtocol(paramValue);
 }
 params += " " + paramName + "=\"" + paramValue + "\"";
 }
 }
 if (inArray(name, vSelfClosingTags)) {
 ending = " /";
 }
 if (inArray(name, vNeedClosingTags)) {
 ending = "";
 }
 if (ending == null || ending.length() < 1) {
 if (vTagCounts.containsKey(name)) {
 vTagCounts.put(name, vTagCounts.get(name) + 1);
 } else {
 vTagCounts.put(name, 1);
 }
 } else {
 ending = " /";
 }
 return "<" + name + params + ending + ">";
 } else {
 return "";
 }
 }
 // comments
 m = P_COMMENT.matcher(s);
 if (!stripComment && m.find()) {
 return "<" + m.group() + ">";
 }
 return "";
 }
 
 private String processParamProtocol(String s) {
 s = decodeEntities(s);
 final Matcher m = P_PROTOCOL.matcher(s);
 if (m.find()) {
 final String protocol = m.group(1);
 if (!inArray(protocol, vAllowedProtocols)) {
 // bad protocol, turn into local anchor link instead
 s = "#" + s.substring(protocol.length() + 1, s.length());
 if (s.startsWith(SS)) {
 s = "#" + s.substring(3, s.length());
 }
 }
 }
 
 return s;
 }
 
 private String decodeEntities(String s) {
 StringBuffer buf = new StringBuffer();
 
 Matcher m = P_ENTITY.matcher(s);
 while (m.find()) {
 final String match = m.group(1);
 final int decimal = Integer.decode(match).intValue();
 m.appendReplacement(buf, Matcher.quoteReplacement(chr(decimal)));
 }
 m.appendTail(buf);
 s = buf.toString();
 
 buf = new StringBuffer();
 m = P_ENTITY_UNICODE.matcher(s);
 while (m.find()) {
 final String match = m.group(1);
 final int decimal = Integer.valueOf(match, 16).intValue();
 m.appendReplacement(buf, Matcher.quoteReplacement(chr(decimal)));
 }
 m.appendTail(buf);
 s = buf.toString();
 
 buf = new StringBuffer();
 m = P_ENCODE.matcher(s);
 while (m.find()) {
 final String match = m.group(1);
 final int decimal = Integer.valueOf(match, 16).intValue();
 m.appendReplacement(buf, Matcher.quoteReplacement(chr(decimal)));
 }
 m.appendTail(buf);
 s = buf.toString();
 
 s = validateEntities(s);
 return s;
 }
 
 private String validateEntities(final String s) {
 StringBuffer buf = new StringBuffer();
 
 // validate entities throughout the string
 Matcher m = P_VALID_ENTITIES.matcher(s);
 while (m.find()) {
 	/**([^&;]*)*/
 final String one = m.group(1);
 /**(?=(;|&|$))*/
 final String two = m.group(2);
 m.appendReplacement(buf, Matcher.quoteReplacement(checkEntity(one, two)));
 }
 m.appendTail(buf);
 
 return encodeQuotes(buf.toString());
 }
 
 private String encodeQuotes(final String s){
 if(encodeQuotes){
 StringBuffer buf = new StringBuffer();
 Matcher m = P_VALID_QUOTES.matcher(s);
 while (m.find()) {
 	/**(>|^)*/
 final String one = m.group(1);
 /**([^<]+?)*/
 final String two = m.group(2); 
 /**(<|$)*/
 final String three = m.group(3);
 m.appendReplacement(buf, Matcher.quoteReplacement(one + regexReplace(P_QUOTE, """, two) + three));
 }
 m.appendTail(buf);
 return buf.toString();
 }else{
 return s;
 }
 }
 
 private String checkEntity(final String preamble, final String term) {
 
 return ";".equals(term) && isValidEntity(preamble)
 ? '&' + preamble
 : "&" + preamble;
 }
 
 private boolean isValidEntity(final String entity) {
 return inArray(entity, vAllowedEntities);
 }
 
 private static boolean inArray(final String s, final String[] array) {
 for (String item : array) {
 if (item != null && item.equals(s)) {
 return true;
 }
 }
 return false;
 }
 
 private boolean allowed(final String name) {
 return (vAllowed.isEmpty() || vAllowed.containsKey(name)) && !inArray(name, vDisallowed);
 }
 
 private boolean allowedAttribute(final String name, final String paramName) {
 return allowed(name) && (vAllowed.isEmpty() || vAllowed.get(name).contains(paramName));
 }
 }

敏感词过滤工具类

import java.io.BufferedReader;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.Serializable;
 import java.util.*;
 
 import org.springframework.core.io.ClassPathResource;
 
 /**
 * Title: SensitiveWordUtils
 * @author: gaodeqiang
 * @date 2018年12月12日
 * @version V1.0
 * Description: 敏感词过滤
 */
 @SuppressWarnings("all")
 public class SensitiveWordUtils implements Serializable {
 
 	private static final long serialVersionUID = 1L;
 
 	private SensitiveWordUtils() {
 	}
 
 	private static SensitiveWordUtils sensitiveWordUtils = null;
 
 	public synchronized static SensitiveWordUtils getSensitiveWordUtils() {
 		if (sensitiveWordUtils == null) {
 			sensitiveWordUtils = new SensitiveWordUtils();
 		}
 		return sensitiveWordUtils;
 	}
 
 	private static Set<String> sensitiveWordSet = null;
 
 	static {
 		try {
 			readResource("keywords.txt");
 		} catch (Exception e) {
 			e.printStackTrace();
 		}
 		// 初始化敏感词库
 		initSensitiveWordMap();
 	}
 
 	private static final int MinMatchTYpe = 1; // 最小匹配规则，如：敏感词库["中国","中国人"]，语句："我是中国人"，匹配结果：我是[中国]人
 	private static final int MaxMatchType = 2; // 最大匹配规则，如：敏感词库["中国","中国人"]，语句："我是中国人"，匹配结果：我是[中国人]
 
 	private static HashMap sensitiveWordMap = new HashMap<>();
 
 	/**
 	 * @author gaodeqiang
 	 * @Description 读取资源文件
 	 * @date 2018年12月13日上午9:29:01
 	 */
 	private static void readResource(String name) throws Exception {
 		ClassPathResource resource = new ClassPathResource(name);
 		InputStream inputStream = resource.getInputStream();
 		InputStreamReader read = new InputStreamReader(inputStream, "utf-8");
 		// 初始化set集合
 		sensitiveWordSet = new HashSet<String>();
 		// 缓冲区读取流
 		BufferedReader bufferedReader = new BufferedReader(read);
 		// 循环读取文件中内容，每次读取一行内容
 		String txt = null;
 		while ((txt = bufferedReader.readLine()) != null) {
 			// 读取文件，将文件内容放入到set中
 			sensitiveWordSet.add(txt);
 		}
 		read.close();
 	}
 
 	/**
 	 * @author gaodeqiang
 	 * @Description 初始化敏感词库，构建DFA算法模型
 	 * @date 2018年12月13日上午9:30:08
 	 */
 	private static void initSensitiveWordMap() {
 		// 初始化敏感词容器，减少扩容操作
 		sensitiveWordMap = new HashMap(sensitiveWordSet.size());
 		String key;
 		Map nowMap;
 		Map<String, String> newWorMap;
 		// 迭代sensitiveWordSet
 		Iterator<String> iterator = sensitiveWordSet.iterator();
 		while (iterator.hasNext()) {
 			// 关键字
 			key = iterator.next();
 			nowMap = sensitiveWordMap;
 			for (int i = 0; i < key.length(); i++) {
 				// 转换成char型
 				char keyChar = key.charAt(i);
 				// 库中获取关键字
 				Object wordMap = nowMap.get(keyChar);
 				// 如果存在该key，直接赋值，用于下一个循环获取
 				if (wordMap != null) {
 					nowMap = (Map) wordMap;
 				} else {
 					// 不存在则，则构建一个map，同时将isEnd设置为0，因为他不是最后一个
 					newWorMap = new HashMap<>();
 					// 不是最后一个
 					newWorMap.put("isEnd", "0");
 					nowMap.put(keyChar, newWorMap);
 					nowMap = newWorMap;
 				}
 
 				if (i == key.length() - 1) {
 					// 最后一个
 					nowMap.put("isEnd", "1");
 				}
 			}
 		}
 	}
 
 	/**
 	 * @author gaodeqiang
 	 * @Description 检查文字中是否包含敏感字符
 	 * @date 2018年12月13日上午9:38:35
 	 */
 	private int checkSensitiveWord(String txt, int beginIndex, int matchType) {
 		// 敏感词结束标识位：用于敏感词只有1位的情况
 		boolean flag = false;
 		// 匹配标识数默认为0
 		int matchFlag = 0;
 		char word;
 		Map nowMap = sensitiveWordMap;
 		for (int i = beginIndex; i < txt.length(); i++) {
 			word = txt.charAt(i);
 			// 获取指定key
 			nowMap = (Map) nowMap.get(word);
 			if (nowMap != null) {// 存在，则判断是否为最后一个
 				// 找到相应key，匹配标识+1
 				matchFlag++;
 				// 如果为最后一个匹配规则,结束循环，返回匹配标识数
 				if ("1".equals(nowMap.get("isEnd"))) {
 					// 结束标志位为true
 					flag = true;
 					// 最小规则，直接返回,最大规则还需继续查找
 					if (MinMatchTYpe == matchType) {
 						break;
 					}
 				}
 			} else {// 不存在，直接返回
 				break;
 			}
 		}
 		if (matchFlag < 2 || !flag) {// 长度必须大于等于1，为词
 			matchFlag = 0;
 		}
 		return matchFlag;
 	}
 
 	/**
 	 * @author gaodeqiang
 	 * @Description 判断文字是否包含敏感字符 匹配规则 1：最小匹配规则，2：最大匹配规则
 	 * @date 2018年12月13日上午9:34:23
 	 */
 	public boolean contains(String txt, int matchType) {
 		boolean flag = false;
 		for (int i = 0; i < txt.length(); i++) {
 			int matchFlag = checkSensitiveWord(txt, i, matchType); // 判断是否包含敏感字符
 			if (matchFlag > 0) { // 大于0存在，返回true
 				flag = true;
 			}
 		}
 		return flag;
 	}
 
 	/**
 	 * @author gaodeqiang
 	 * @Description 获取文字中的敏感词
 	 * @date 2018年12月13日上午9:36:00
 	 */
 	public Set<String> getSensitiveWord(String txt, int matchType) {
 		Set<String> sensitiveWordList = new HashSet<>();
 
 		for (int i = 0; i < txt.length(); i++) {
 			// 判断是否包含敏感字符
 			int length = checkSensitiveWord(txt, i, matchType);
 			if (length > 0) {// 存在,加入list中
 				sensitiveWordList.add(txt.substring(i, i + length));
 				i = i + length - 1;// 减1的原因，是因为for会自增
 			}
 		}
 
 		return sensitiveWordList;
 	}
 
 	/**
 	 * @author gaodeqiang
 	 * @Description 替换敏感字字符
 	 * @date 2018年12月13日上午9:36:34
 	 */
 	public String replaceSensitiveWord(String txt, char replaceChar, int matchType) {
 		String resultTxt = txt;
 		// 获取所有的敏感词
 		Set<String> set = getSensitiveWord(txt, matchType);
 		Iterator<String> iterator = set.iterator();
 		String word;
 		String replaceString;
 		while (iterator.hasNext()) {
 			word = iterator.next();
 			replaceString = getReplaceChars(replaceChar, word.length());
 			resultTxt = resultTxt.replaceAll(word, replaceString);
 		}
 
 		return resultTxt;
 	}
 
 	/**
 	 * @author gaodeqiang
 	 * @Description 获取替换字符串
 	 * @date 2018年12月13日上午9:37:53
 	 */
 	private String getReplaceChars(char replaceChar, int length) {
 		String resultReplace = String.valueOf(replaceChar);
 		for (int i = 1; i < length; i++) {
 			resultReplace += replaceChar;
 		}
 		return resultReplace;
 	}
 }