为什么就转不到指定的jsp页面呢

CategoryServlet.java的代码:

package cn.com.zwb.blog;

import java.io.IOException;
//import java.sql.Connection;
//import java.sql.PreparedStatement;
import java.sql.SQLException; //import java.io.PrintWriter;
import java.util.List;

import javax.naming.Context;
import javax.naming.InitialContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.sql.DataSource;

import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanListHandler;

public class CategoryServlet extends HttpServlet {

private static final long serialVersionUID = 1L;

public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request, response);
}

public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//解决从JSP页面接受中文参数乱码
request.setCharacterEncoding("UTF-8");
        String method= request.getParameter("method");   
    if (method.equals("add")){
        add