Servlet（增删改查）
准备：1.新建一个web项目（StudentZSGC）
2.分层,分包
一．查（查询学员信息
表
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）
（1）新建一个JSP页面（通过form表单进一个servlet（StudentAction））
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServername()+":"+request.getServerPort()+path+"/";
%>
查询学员表
（2）通过web.xml(中转站)找到对应的servlet（StudentAction）
（3）进入action层
package com.student.action;
import java.io.IOException;
import java.util.List;
import java.util.Map;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.student.service.StudentService;
public class StudentAction extends HttpServlet {
/**
* 查询所有人员
*/
private static final long serialVersionUID = 1L;
@Override
protected void service(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
//转码
req.setCharacterEncoding("utf-8");
resp.setCharacterEncoding("utf-8");
resp.setContentType("text/html; charset=utf-8");
//调方法
StudentService studentService=new StudentService();
List
> list=null;
list=studentService.selectAll();
req.setAttribute("StudentList", list);--传回前台进行set
//转向
if(!list.isEmpty()){ --跳转到该页面
req.getRequestDispatcher("Student.jsp").forward(req, resp);
}else{
req.getRequestDispatcher("Student.jsp").forward(req, resp);
}
}
}
（4）进入service类中
package com.student.service;
import java.util.List;
import java.util.Map;
import com.student.dao.StudentDao;
/**
* 查询所有学员信息方法
* @author Administrator
*/
public class StudentService {
public List> selectAll() {
StudentDao StudentDao=new StudentDao();
return StudentDao.selectAll();
}
}
（5）进入dao中连接数据库
package com.student.dao;
import java.util.List;
/**
* 查询数据库所有学员 放到list中
*/
import java.util.Map;
import com.student.util.Dao;
public class StudentDao {
Dao dao=new Dao();
public List> selectAll() {
String sql="select s_id, s_number, s_name, s_sex, s_class, s_age, s_add, s_college, s_mobile, s_hobby from student";
return dao.select(sql,new Object[]{});
}
}
（6）查询出数据后跳到Student.jsp页面
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@page import="java.sql.Array"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServername()+":"+request.getServerPort()+path+"/";
%>
学员列表
