过滤器-无效数据过滤

packagecom.loaderman.demo.b_filter_data;
importjava.io.IOException;
importjava.lang.reflect.InvocationHandler;
importjava.lang.reflect.Method;
importjava.lang.reflect.Proxy;
importjava.util.ArrayList;
importjava.util.List;
importjavax.servlet.Filter;
importjavax.servlet.FilterChain;
importjavax.servlet.FilterConfig;
importjavax.servlet.ServletException;
importjavax.servlet.ServletRequest;
importjavax.servlet.ServletResponse;
importjavax.servlet.http.HttpServletRequest;
importjavax.servlet.http.HttpServletResponse;
/**
 * 无效数据过滤
 *
 */
public class DateFilter implementsFilter {
    //初始化无效数据
    private List<String>dirtyData;
    @Override
    public void init(FilterConfig filterConfig) throwsServletException {
        //模拟几个数据
        dirtyData = new ArrayList<String>();
        dirtyData.add("NND");
        dirtyData.add("炸使馆");
    }
    @Override
    public voiddoFilter(ServletRequest req, ServletResponse res,
                         FilterChain chain) throwsIOException, ServletException {
        //转型
        final HttpServletRequest request =(HttpServletRequest) req;
        HttpServletResponse response =(HttpServletResponse) res;
        //一、处理公用业务
        request.setCharacterEncoding("UTF-8");                    //POST提交有效
        response.setContentType("text/html;charset=UTF-8");
        HttpServletRequest proxy =(HttpServletRequest) Proxy.newProxyInstance(
                request.getClass().getClassLoader(),         //指定当前使用的累加载器
                new Class[]{HttpServletRequest.class},         //对目标对象实现的接口类型
                new InvocationHandler() {                    //事件处理器
@Override
                    publicObject invoke(Object proxy, Method method, Object[] args)
                            throwsThrowable {
                        //定义方法返回值
                        Object returnValue = null;
                        //获取方法名
                        String methodName =method.getName();
                        //判断：对getParameter方法进行GET提交中文处理
                        if ("getParameter".equals(methodName)) {
                            //获取请求数据值【 <input type="text" name="userName">】
                            String value = request.getParameter(args[0].toString());    //调用目标对象的方法
                            //获取提交方式
                            String methodSubmit = request.getMethod(); //直接调用目标对象的方法
                            //判断如果是GET提交，需要对数据进行处理  (POST提交已经处理过了)
                            if ("GET".equals(methodSubmit)) {
                                if (value != null && !"".equals(value.trim())){
                                    //处理GET中文
                                    value = new String(value.getBytes("ISO8859-1"),"UTF-8");
                                }
                            }
                            //中文数据已经处理完： 下面进行无效数据过滤
                            //【如何value中出现dirtyData中数据，用****替换】
                            for(String data : dirtyData) {
                                //判断当前输入数据(value), 是否包含无效数据
                                if(value.contains(data)){
                                    value = value.replace(data, "*****");
                                }
                            }
                            //处理完编码、无效数据后的正确数据
                            returnvalue;
                        }
                        else{
                            //执行request对象的其他方法
                            returnValue =method.invoke(request, args);
                        }
                        returnreturnValue;
                    }
                });
        //二、放行 (执行下一个过滤器或者servlet)
        chain.doFilter(proxy, response);        //传入代理对象
}
    @Override
    public voiddestroy() {
    }
}

packagecom.loaderman.demo.b_filter_data;
importjava.io.IOException;
importjava.io.PrintWriter;
importjavax.servlet.ServletException;
importjavax.servlet.http.HttpServlet;
importjavax.servlet.http.HttpServletRequest;
importjavax.servlet.http.HttpServletResponse;
public class DisServlet extendsHttpServlet {
    public voiddoGet(HttpServletRequest request, HttpServletResponse response)
            throwsServletException, IOException {
        //获取请求数据
        String content = request.getParameter("content");
        //保存到request
        request.setAttribute("content", "Content：" +content);
        //转发
        request.getRequestDispatcher("/dis.jsp").forward(request, response);
    }
    public voiddoPost(HttpServletRequest request, HttpServletResponse response)
            throwsServletException, IOException {
        this.doGet(request, response);
    }
}

 <!-- 2. 无效数据过滤器配置 -->
    <filter>
        <filter-name>dataFilter</filter-name>
        <filter-class>com.loaderman.demo.b_filter_data.DateFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>dataFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>