web编程的乱码问题
[code=HTML][/code]我重新编辑了一个东西，是页面转移的，由AddServlet.java,BookWriter.java,Book.java,hello.jsp源代码按顺序如下
package jp.bcat;import java.io.*;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.*;import java.text.SimpleDateFormat;import java.util.Date;/** * Servlet implementation class AddServlet */@WebServlet("/AddServlet")public class AddServlet extends HttpServlet { private static final long serialVersionUID = 1L; /** * @see HttpServlet#HttpServlet() */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub String step = request.getParameter("step"); if ("prepare".equals(step)) prepare(request, response); } void prepare(HttpServletRequest request, HttpServletResponse response) throws IOException { String errorMessage = ""; Book book = new Book(); String title = request.getParameter("title"); book.setTitle(title); if (title == null || title.length() == 0) errorMessage += "<P>タイトルを入力してください。</P>"; response.setContentType("text/html; charset=utf-8"); PrintWriter out = response.getWriter(); out.println("<HTML><HEAD><TITLE>図書登録確認</TITLE></HEAD>"); if (errorMessage.length() == 0) { out.println("<BODY>"); out.println("<PRE>"); new BookWriter(out, "+ ").write(book); out.println("</PRE>"); out.println("</BODY>"); } out.println("</HTML>"); }}package jp.bcat;import java.io.PrintWriter;public class BookWriter { protected PrintWriter out; protected String indent; public BookWriter(PrintWriter out, String indent) { this.out = out; this.indent = indent; } public void write(Book book) { out.println(indent + "タイトル: " + book.getTitle()); }}package jp.bcat;import java.io.Serializable;public class Book implements Serializable { protected String title; public String getTitle() { return title; } public void setTitle(String value) { title = value; }}<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="windows-31j"%><!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="AddServlet" method="POST"> <TABLE> <TR><TD>タイトル: </TD><TD><INPUT name="title"></TD></TR> <TR><TD><INPUT type="submit" value="登録"></TD></TR> <INPUT type="hidden" name="step" value="prepare"> </TABLE> </FORM></body></html>
package jp.bcat.util;import java.io.IOException;import javax.servlet.*;public class RequestEncodingFilter implements Filter { private String encoding; public void init(FilterConfig config) throws ServletException { encoding = config.getInitParameter("encoding"); } public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException { if (encoding != null) req.setCharacterEncoding(encoding); chain.doFilter(req, res); } public void destroy() { }}