下面是我写的一个实验的源代码,没办法显示汉字,请各位指教?import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;public class Servlet1 extends HttpServlet {
    private static final String CONTENT_TYPE = "text/html; charset=GBK";    //Initialize global variables
    public void init() throws ServletException {
    }    //Process the HTTP Get request
    public void doGet(HttpServletRequest request, HttpServletResponse response) throws
            ServletException, IOException {
        response.setContentType(CONTENT_TYPE);
        PrintWriter out = response.getWriter();
        request.setCharacterEncoding("GBK");
        response.setCharacterEncoding("GBK");
        String username=request.getParameter("username");
        String useremail=request.getParameter("useremail");
        if(username==null || useremail==null){
            UserInput(out);
        }else{
            out.println("<html>");
            out.println("<head><title>Servlet1</title></head>");
            out.println("<body bgcolor=\"#ffffff\">");
            out.println("<table>");
            out.println("<tr>");
            out.println("<td>");
            out.println("姓名");
            out.println("</td>");
            out.println("<td>");
            out.println(username);
            out.println("</td>");
            out.println("</tr>");
            out.println("<tr>");
            out.println("<td>");
            out.println("邮箱");
            out.println("</td>");
            out.println("<td>");
            out.println(useremail);
            out.println("</td>");
            out.println("</tr>");
            out.println("</table>");
            out.println("</body>");
            out.println("</html>");
            out.close();
        }
    }    //Clean up resources
    public void destroy() {
    }
    public void UserInput(PrintWriter out){
        out.println("<html>");
        out.println("<head><title>Servlet1</title></head>");
        out.println("<body bgcolor=\"#ffffff\">");
        out.println("<center>");
        out.println("<form action='/WebModule1/servlet1' method='GET'>");
        out.println("<table>");
        out.println("<tr>");
        out.println("<td>");
        out.println("姓名");
        out.println("</td>");
        out.println("<td>");
        out.println("<input type='text' name='username' value=''>");
        out.println("</td>");
        out.println("</tr>");
        out.println("<tr>");
        out.println("<td>");
        out.println("邮箱");
        out.println("</td>");
        out.println("<td>");
        out.println("<input type='text' name='useremail' value=''>");
        out.println("</td>");
        out.println("</tr>");
        out.println("</table>");
        out.println("</form>");
        out.println("<input type='submit' value='提交'>");
        out.println("<input type='reset' value='重置'>");
        out.println("</center>");
        out.println("</body>");
        out.println("</html>");
        out.close();    }
}