1.编写XssFilter
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;
import com.itcast.utils.XssHttpServletRequestWrapper;

/**
 *  XSS防跨站脚本攻击过滤器
 *
 */
public class XssFilter implements Filter {
    FilterConfig filterConfig = null;
    /**
     * Default constructor.
     */
    public XssFilter() {
    }

    public void destroy() {
        this.filterConfig = null;
    }

    public void init(FilterConfig fConfig) throws ServletException {
        this.filterConfig = fConfig;
    }

    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        chain.doFilter(new XssHttpServletRequestWrapper((HttpServletRequest) request), response);
    }


}

2.编写XssHttpServletRequestWrapper类

import java.util.Enumeration;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;

import org.apache.struts2.dispatcher.StrutsRequestWrapper;
import org.springframework.util.CollectionUtils;

public class XssHttpServletRequestWrapper extends StrutsRequestWrapper  {

    HttpServletRequest orgRequest = null;

    public XssHttpServletRequestWrapper(HttpServletRequest servletRequest) {
        super(servletRequest);
        orgRequest = servletRequest;
    }

    /**
     * 重写getParameterValues方法
     * 通过循环取出每一个请求结果
     * 再对请求结果进行过滤
     * */
    public String[] getParameterValues(String parameter) {
        String[] values = super.getParameterValues(parameter);
        if (values == null) {
            return null;
        }
        int count = values.length;
        String[] encodedValues = new String[count];
        for (int i = 0; i < count; i++) {
            encodedValues[i] = cleanXSS(values[i]);
        }
        return encodedValues;
    }

    /**
     * 重写getParameter方法
     * 对请求结果进行过滤
     * */
    public String getParameter(String parameter) {
        String value = super.getParameter(parameter);
        if (value == null) {
            return null;
        }
        return cleanXSS(value);
    }

    public String getHeader(String name) {
        String value = super.getHeader(name);
        if (value == null)
            return null;
        return cleanXSS(value);
    }
    /**
     * 获取最原始的request
     *
     * @return
     */
    public HttpServletRequest getOrgRequest() {
        return orgRequest;
    }

    /**
     * 获取最原始的request的静态方法
     *
     * @return
     */
    public static HttpServletRequest getOrgRequest(HttpServletRequest req) {
        if (req instanceof XssHttpServletRequestWrapper) {
            return ((XssHttpServletRequestWrapper) req).getOrgRequest();
        }
        return req;
    }

    @Override
    public Enumeration<String> getParameterNames() {
        Enumeration<String> names = super.getParameterNames();
        while(names.hasMoreElements()){
            String name = names.nextElement();
            name = cleanXSS(name);
        }
        return names;
    }


    @Override
    public Map getParameterMap() {

        Map paramMap = super.getParameterMap();
        if (CollectionUtils.isEmpty(paramMap)) {
            return paramMap;
        }

        for (Object value : paramMap.values()) {
            String[] str = (String[])value;
            if (str != null) {
                for (int i = 0; i < str.length; i++) {

                    str[i] = cleanXSS(str[i]);
                }
            }
        }
        return paramMap;
    }

    private String cleanXSS(String value) {
        value = value.replaceAll("<", "& lt;").replaceAll(">", "& gt;");
        //先暂时去除 英文括号的拦截
//        value = value.replaceAll("\\(", "& #40;").replaceAll("\\)", "& #41;");
        value = value.replaceAll("'", "& #39;");
        value = value.replaceAll("eval\\((.*)\\)", "");
        value = value.replaceAll("[\\\"\\\'][\\s]*javascript:(.*)[\\\"\\\']","\"\"");
        value = value.replaceAll("script", "");
        value = value.replaceAll("alert", "");

        return value;
    }
}

3.注解配置web.xml 过滤器XssFilter

注意：struts-xssFilter一定要在StrutsPrepareAndExecuteFilter之前执行否则无效，具体体现在struts-xssFilter自定义过滤器在StrutsPrepareAndExecuteFilter注解之上。

<filter>
    <filter-name>struts-xssFilter</filter-name>
    <filter-class>
        com.itcast.filter.XssFilter
    </filter-class>
</filter>

<filter-mapping>
    <filter-name>struts-xssFilter</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

<filter>
    <filter-name>struts2</filter-name>
    <filter-class>
        org.apache.struts2.dispatcher.filter.StrutsPrepareAndExecuteFilter
    </filter-class>
</filter>

<filter-mapping>
    <filter-name>struts2</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

4.效果演示

输入富文本

后端接收过滤后文本（特殊字符经过转译）

有用请给个赞，手打亲测不易！