studentservlet.java

一个extjs编写的代码

package anni.student;

import java.sql.*;
import java.util.*;

import javax.servlet.*;
import javax.servlet.http.*;

import anni.json.*;

public class StudentServlet extends HttpServlet {
    public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException {
        try {
            process(request, response);
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }

    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException {
        try {
            process(request, response);
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }

    public void process(HttpServletRequest request, HttpServletResponse response) throws Exception {
        String action = request.getParameter("action");
        if (action.equals("list")) {
            Connection conn = DbUtils.getConn();
            Statement state = conn.createStatement();
            ResultSet rs = state.executeQuery("select * from student");
            List list = new ArrayList();
            while (rs.next()) {
                Student student = new Student();
                student.setId(rs.getLong("id"));
                student.setCode(rs.getString("code"));
                student.setName(rs.getString("name"));
                student.setSex(rs.getString("sex"));
                student.setAge(rs.getInt("age"));
                student.setPolitical(rs.getString("political"));
                student.setOrigin(rs.getString("origin"));
                student.setProfessional(rs.getString("professional"));
                list.add(student);
            }
            conn.close();
            Page page = new Page(list.size(), list);
            new JsonUtils().write(page, response.getWriter());
        } else if (action.equals("save")) {
            Connection conn = DbUtils.getConn();
            Statement state = conn.createStatement();
            ResultSet rs = state.executeQuery("select count (*) from student");
            long count = 1;
            if (rs.next()) {
                count = rs.getLong(1) + 1;
            }

            String code = request.getParameter("code");
            String name = request.getParameter("name");
            String sex = request.getParameter("sex");
            String age = request.getParameter("age");
            String political = request.getParameter("political");
            String origin = request.getParameter("origin");
            String professional = request.getParameter("professional");
            PreparedStatement pstate = conn.prepareStatement("insert into student(id,code,name,sex,age,political,origin,professional) values(?,?,?,?,?,?,?,?)");
            pstate.setLong(1, count);
            pstate.setString(2, code);
            pstate.setString(3, name);
            pstate.setString(4, sex);
            pstate.setInt(5, Integer.parseInt(age));
            pstate.setString(6, political);
            pstate.setString(7, origin);
            pstate.setString(8, professional);
            pstate.executeUpdate();
            conn.close();
            response.getWriter().print("{success:true,msg:'添加成功'}");
        } else if (action.equals("update")) {
            Connection conn = DbUtils.getConn();
            String id = request.getParameter("id");
            String code = request.getParameter("code");
            String name = request.getParameter("name");
            String sex = request.getParameter("sex");
            String age = request.getParameter("age");
            String political = request.getParameter("political");
            String origin = request.getParameter("origin");
            String professional = request.getParameter("professional");
            PreparedStatement pstate = conn.prepareStatement("update student set code=?,name=?,sex=?,age=?,political=?,origin=?,professional=? where id=?");
            pstate.setString(1, code);
            pstate.setString(2, name);
            pstate.setString(3, sex);
            pstate.setInt(4, Integer.parseInt(age));
            pstate.setString(5, political);
            pstate.setString(6, origin);
            pstate.setString(7, professional);
            pstate.setLong(8, Long.parseLong(id));
            pstate.executeUpdate();
            conn.close();
            response.getWriter().print("{success:true,msg:'修改成功'}");
        } else if (action.equals("remove")) {
            Connection conn = DbUtils.getConn();
            String id = request.getParameter("id");
            Statement state = conn.createStatement();
            state.executeUpdate("delete from student where id=" + id);
            conn.close();
            response.getWriter().print("{success:true,msg:'删除成功'}");
        }
    }
}