2020.12.02
一、今日学习内容
关于志愿者系统:
Dao:
package Dao; import java.sql.Connection; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import java.util.ArrayList; import java.util.List; import entity.Teenager; import util.DBUtil; public class TeenagerDao { public boolean add(Teenager ten) { String sql="insert into teenager(name,sex,minzu,shijian,age,mianmao,fuwu)values" + "('" + ten.getName() + "','" + ten.getSex() + "','" + ten.getMinzu() + "','" + ten.getShijian() + "','" + ten.getAge() + "','" + ten.getMianmao() + "','" + ten.getFuwu() + "')"; //创建数据库链接 Connection conn=DBUtil.getConn(); Statement state=null; boolean f=false; int a = 0; try { state = conn.createStatement(); a=state.executeUpdate(sql); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } finally { //关闭连接 DBUtil.close(state, conn); } if(a>0) f=true; return f; } public Teenager getbyname(String name) { String sql = "select * from teenager where name ='" + name + "'"; Connection conn = DBUtil.getConn(); Statement state = null; ResultSet rs = null; Teenager ten = null; try { state = conn.createStatement(); rs = state.executeQuery(sql); while (rs.next()) { int id=rs.getInt("id"); String sex2 = rs.getString("sex"); String minzu2 = rs.getString("minzu"); String age=rs.getString("age"); String mianmao2 = rs.getString("mianmao"); String fuwu2 =rs.getString("fuwu"); String shijian2=rs.getString("shijian"); ten = new Teenager(id,name, sex2, minzu2,shijian2,age,mianmao2,fuwu2); } } catch (Exception e) { e.printStackTrace(); } finally { DBUtil.close(rs, state, conn); } return ten; } //delete public boolean delete(String name) { String sql="delete * from teenager where name='" + name + "'"; Connection conn = DBUtil.getConn(); Statement state = null; int a = 0; boolean f = false; try { state = conn.createStatement(); a=state.executeUpdate(sql); } catch (SQLException e) { e.printStackTrace(); } finally { DBUtil.close(state, conn); } if (a > 0) { f = true; } return f; } //update public boolean update(Teenager ten) { String sql="update teenager set name='" + ten.getName() + "',sex='" + ten.getSex() + "',minzu='" + ten.getMinzu() + "',shijian='" + ten.getShijian() + "',age='" + ten.getAge() + "',mianmao='" + ten.getMianmao() + "',fuwu='" + ten.getFuwu() + "' where id='" + ten.getId() + "'"; Connection conn = DBUtil.getConn(); Statement state = null; boolean f = false; int a = 0; try { state = conn.createStatement(); a = state.executeUpdate(sql); } catch (SQLException e) { e.printStackTrace(); } finally { DBUtil.close(state, conn); } if (a > 0) { f = true; } return f; } //姓名不得重复 public boolean name(String name) { boolean flag = false; String sql = "select name from teenager where name = '" + name + "'"; Connection conn = DBUtil.getConn(); Statement state = null; ResultSet rs = null; try { state=conn.createStatement(); rs = state.executeQuery(sql); while (rs.next()) { flag = true; } } catch (SQLException e) { e.printStackTrace(); } finally { DBUtil.close(rs, state, conn); } return flag; } //查找 public List<Teenager> search(String name,String sex,String minzu,String mianmao,String fuwu,String shijian) { String sql = "select * from teenager where "; if (name != "") { sql += "name like '%" +name+ "%'"; } if (sex != "") { sql += "sex like '%" +sex+ "%'"; } if(minzu!="") { sql+="minzu like '%"+minzu+ "%'"; } if(mianmao!="") { sql+="mianmao like '%" +mianmao+ "%'"; } if(fuwu!="") { sql+="fuwu like '%" +fuwu+ "%'"; } if(shijian!="") { sql+="shijian like '%" +shijian+ "%'"; } List<Teenager> list = new ArrayList<>(); Connection conn = DBUtil.getConn(); Statement state = null; ResultSet rs = null; Teenager bean = null; try { state = conn.createStatement(); rs = state.executeQuery(sql); while (rs.next()) { String name2=rs.getString("name"); String sex2 = rs.getString("sex"); String minzu2 = rs.getString("minzu"); String age=rs.getString("age"); String mianmao2 = rs.getString("mianmao"); String fuwu2 =rs.getString("fuwu"); String shijian2=rs.getString("shijian"); bean =new Teenager(name2, sex2, minzu2,shijian2,age,mianmao2,fuwu2); list.add(bean); } } catch (SQLException e) { e.printStackTrace(); } finally { DBUtil.close(rs, state, conn); } return list; } //全部数据 public List<Teenager> list() { String sql = "select * from teenager"; List<Teenager> list = new ArrayList<>(); Connection conn = DBUtil.getConn(); Statement state = null; ResultSet rs = null; try { state = conn.createStatement(); rs = state.executeQuery(sql); while (rs.next()) { Teenager bean = null; int id=rs.getInt("id"); String name2=rs.getString("name"); String sex2 = rs.getString("sex"); String minzu2 = rs.getString("minzu"); String age=rs.getString("age"); String mianmao2 = rs.getString("mianmao"); String fuwu2 =rs.getString("fuwu"); String shijian2=rs.getString("shijian"); bean =new Teenager(id,name2, sex2, minzu2,shijian2,age,mianmao2,fuwu2); list.add(bean); } } catch (SQLException e) { e.printStackTrace(); } finally { DBUtil.close(rs, state, conn); } return list; } }
service:
package service; import java.util.List; import Dao.TeenagerDao; import entity.Teenager; public class TeenagerService { TeenagerDao tDao=new TeenagerDao(); public boolean add(Teenager ten) { boolean f = false; if(!tDao.name(ten.getName())) { tDao.add(ten); f=true; } return f; } public boolean del(String name) { tDao.delete(name); return true; } public boolean update(Teenager ten) { tDao.update(ten); return true; } public Teenager getbyname(String name) { return tDao.getbyname(name); } public List<Teenager> search(String name,String sex,String minzu,String mianmao,String fuwu,String shijian) { return tDao.search(name, sex,minzu,mianmao,fuwu,shijian); } //查找所有人 public List<Teenager> list() { return tDao.list(); } }
entity:
package entity; public class Teenager { private int id; private String name; private String sex; private String minzu; private String shijian; private String age; private String mianmao; private String fuwu; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getSex() { return sex; } public void setSex(String sex) { this.sex = sex; } public String getMinzu() { return minzu; } public void setMinzu(String minzu) { this.minzu = minzu; } public String getShijian() { return shijian; } public void setShijian(String shijian) { this.shijian = shijian; } public String getAge() { return age; } public void setAge(String age) { this.age = age; } public String getMianmao() { return mianmao; } public void setMianmao(String mianmao) { this.mianmao = mianmao; } public String getFuwu() { return fuwu; } public void setFuwu(String fuwu) { this.fuwu = fuwu; } public Teenager(int id, String name, String sex, String minzu, String shijian, String age, String mianmao,String fuwu) { super(); this.id = id; this.name = name; this.sex = sex; this.minzu = minzu; this.shijian = shijian; this.age = age; this.mianmao = mianmao; this.fuwu = fuwu; } public Teenager(String name, String sex, String minzu, String shijian, String age, String mianmao, String fuwu) { super(); this.name = name; this.sex = sex; this.minzu = minzu; this.shijian = shijian; this.age = age; this.mianmao = mianmao; this.fuwu = fuwu; } public Teenager() {} }
servlet:
package servlet; import java.io.IOException; import java.util.List; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import entity.Teenager; import service.TeenagerService; @WebServlet("/TeenagerServlet") public class TeenagerServlet extends HttpServlet{ private static final long serialVersionUID = 1L; TeenagerService service = new TeenagerService(); /** * 方法选择 */ protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { req.setCharacterEncoding("utf-8"); String method = req.getParameter("method"); if ("add".equals(method)) { add(req,resp); } else if ("del".equals(method)) { del(req, resp); } else if ("update".equals(method)) { update(req, resp); } else if ("search".equals(method)) { search(req, resp); } else if ("list".equals(method)) { list(req, resp); } else if("getbyname".equals(method)) { getbyname(req,resp); }else if("getbyname2".equals(method)) { getbyname2(req,resp); } } private void getbyname(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{ req.setCharacterEncoding("utf-8"); String name = req.getParameter("name"); Teenager ten = service.getbyname(name); if(ten==null) { req.setAttribute("message", "未找到该学生"); req.getRequestDispatcher("del.jsp").forward(req, resp); } else { req.setAttribute("ten", ten); req.getRequestDispatcher("del2.jsp").forward(req,resp); } } private void getbyname2(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{ req.setCharacterEncoding("utf-8"); String name = req.getParameter("name"); Teenager ten = service.getbyname(name); if(ten==null) { req.setAttribute("message", "未找到该学生"); req.getRequestDispatcher("xiugai.jsp").forward(req, resp); } else { req.setAttribute("ten", ten); req.getRequestDispatcher("update.jsp").forward(req,resp); } } private void add(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException { req.setCharacterEncoding("utf-8"); //获取数据 String name=req.getParameter("name"); String sex = req.getParameter("sex"); String minzu = req.getParameter("minzu"); String shijian = req.getParameter("shijian"); String age =req.getParameter("age"); String mianmao=req.getParameter("mianmao"); String[] fuwus = req.getParameterValues("fuwu"); StringBuffer buf = new StringBuffer(); for(String fuwu : fuwus){ buf.append(fuwu); } String fuwu = buf.toString(); Teenager ten =new Teenager(name, sex, minzu,shijian,age,mianmao,fuwu); //添加后消息显示 if(service.add(ten)) { req.setAttribute("message", "添加成功"); req.getRequestDispatcher("add.jsp").forward(req,resp); } else { req.setAttribute("message", "姓名重复，请重新录入"); req.getRequestDispatcher("add.jsp").forward(req,resp); } } private void list(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{ req.setCharacterEncoding("utf-8"); List<Teenager> tens = service.list(); req.setAttribute("tens", tens); req.getRequestDispatcher("list.jsp").forward(req,resp); } private void del(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{ req.setCharacterEncoding("utf-8"); String name=req.getParameter("name"); service.del(name); req.setAttribute("message", "删除成功！"); req.getRequestDispatcher("del.jsp").forward(req,resp); } private void update(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{ req.setCharacterEncoding("utf-8"); int id = Integer.parseInt(req.getParameter("id")); String name=req.getParameter("name"); String sex = req.getParameter("sex"); String minzu = req.getParameter("minzu"); String shijian = req.getParameter("shijian"); String age =req.getParameter("age"); String mianmao=req.getParameter("mianmao"); int num=0; String [] fuwus = req.getParameterValues("fuwu"); StringBuffer buf = new StringBuffer(); for(String fuwu : fuwus){ buf.append(fuwu); num++; } String fuwu = buf.toString(); if(num>4) { req.setAttribute("message", "服务类别不得超过四个"); req.getRequestDispatcher("TeenagerServlet?method=getbyname2").forward(req,resp); } Teenager ten =new Teenager(id,name, sex, minzu,shijian,age,mianmao,fuwu); service.update(ten); req.setAttribute("message", "修改成功"); req.getRequestDispatcher("TeenagerServlet?method=list").forward(req,resp); } private void search(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException{ req.setCharacterEncoding("utf-8"); String name=req.getParameter("name"); String sex = req.getParameter("sex"); String minzu = req.getParameter("minzu"); String shijian = req.getParameter("shijian"); String mianmao=req.getParameter("mianmao"); String fuwu=req.getParameter("fuwu"); List<Teenager> tens = service.search(name, sex,minzu,mianmao,fuwu,shijian); if(tens==null) { req.setAttribute("message", "没有该学生"); req.getRequestDispatcher("search.jsp").forward(req,resp); } else { req.setAttribute("tens", tens); req.getRequestDispatcher("list2.jsp").forward(req,resp); } } }
DBUtil:
package util; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; /** * ���ݿ����ӹ��� * @author Zheng * */ public class DBUtil { public static String db_url = "jdbc:mysql://localhost:3306/test?useSSL=false"; public static String db_user = "root"; public static String db_pass = "08301016"; public static Connection getConn () { Connection conn = null; try { Class.forName("com.mysql.jdbc.Driver");//�������� conn = DriverManager.getConnection(db_url, db_user, db_pass); } catch (Exception e) { e.printStackTrace(); } return conn; } /** * �ر����� * @param state * @param conn */ public static void close (Statement state, Connection conn) { if (state != null) { try { state.close(); } catch (SQLException e) { e.printStackTrace(); } } if (conn != null) { try { conn.close(); } catch (SQLException e) { e.printStackTrace(); } } } public static void close (ResultSet rs, Statement state, Connection conn) { if (rs != null) { try { rs.close(); } catch (SQLException e) { e.printStackTrace(); } } if (state != null) { try { state.close(); } catch (SQLException e) { e.printStackTrace(); } } if (conn != null) { try { conn.close(); } catch (SQLException e) { e.printStackTrace(); } } } public static void main(String[] args) throws SQLException { Connection conn = getConn(); PreparedStatement pstmt = null; ResultSet rs = null; String sql ="select * from teenager"; pstmt = conn.prepareStatement(sql); rs = pstmt.executeQuery(); if(rs.next()){ System.out.println("空"); }else{ System.out.println("不空"); } } }
二、遇到的问题：
开始的数据传不到数据库
三、明日计划
明天找错误原因
