1.專案結構

2.1EncodingFilter

package com;

import java.io.IOException;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.ArrayList;
import java.util.List;

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.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet Filter implementation class EncodingFilter
 */
@WebFilter(urlPatterns = "/*")
public class EncodingFilter implements Filter {

	private List<String> list;
	/**
	 * Default constructor.
	 */
	public EncodingFilter() {
	}

	/**
	 * @see Filter#destroy()
	 */
	public void destroy() {
	}

	/**
	 * @see Filter#doFilter(ServletRequest, ServletResponse, FilterChain)
	 */
	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
			throws IOException, ServletException {
		// TODO Auto-generated method stub
		// place your code here
		// System.out.println("EncodingFilter生效");
		HttpServletRequest req = (HttpServletRequest) request;
		HttpServletResponse resp = (HttpServletResponse) response;
		// 解決post中文亂碼問題
		req.setCharacterEncoding("utf-8");
		resp.setContentType("text/html;charset=utf-8");

		// 解決get中文亂碼問題
		HttpServletRequest proxy = (HttpServletRequest) Proxy.newProxyInstance(req.getClass().getClassLoader(),
				new Class[] { HttpServletRequest.class }, new InvocationHandler() {

					@Override
					public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
						String methodName = method.getName();
						if ("getParameter".equals(methodName)) {
							// 解決get中文亂碼問題	
							// 接受此方法的引數
							String value=req.getParameter(args[0].toString());
							// 判斷請求方式-獲取當前請求的方式 GET POST
							String methodSubmit=req.getMethod();
							if("GET".equals(methodSubmit)) {
								// 非空判斷
								if(value!=null && value.length()>0) {
									// 對接受到的引數進行編碼
									value=new String(value.getBytes("ISO-8859-1"),"utf-8");
								}
							}
							for(String str:list) {
								if(value.contains(str)) {
									value=value.replace(str, "*");
								}
							}
							return value;
						} else {
							Object returnValue = method.invoke(req, args);
							return returnValue;
						}
					}
				});
		// pass the request along the filter chain
		chain.doFilter(proxy, response);
	}

	/**
	 * @see Filter#init(FilterConfig)
	 */
	public void init(FilterConfig fConfig) throws ServletException {
		list=new ArrayList<String>();
		list.add("妹");
		list.add("媽");
		list.add("蛋");
	}

}
 

package com;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class LoginServlet
 */
@WebServlet("/LoginServlet")
public class LoginServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public LoginServlet() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
			String msg=request.getParameter("msg");
			request.setAttribute("result", msg);
			request.getRequestDispatcher("/msg.jsp").forward(request, response);;
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}

}
 

<%@ page language="java" contentType="text/html; charset=UTF-8"
	pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
	<form action="${pageContext.request.contextPath}/LoginServlet" method="post">
		<input type="text" name="msg"/>
		<input type="submit" value="測試"/>
	</form>
</body>
</html>
 

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
	顯示頁面的資訊:${result }
</body>
</html>