JavaWeb——课程管理系统（2）.java---18.11.29

DaoFactory.java

package com.jaovo.msg.Util;

import com.jaovo.msg.dao.UserDaoImpl;

public class DaoFactory {
 public static UserDaoImpl getDaoImpl() {
  return new UserDaoImpl();
 }
}

 

DBUtil.java

 

package com.jaovo.msg.Util;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class DBUtil {
 //连接数据库
 public  static  Connection getConnection() {
  try {
   //1 加载驱动
   Class.forName("com.mysql.jdbc.Driver").newInstance();
  } catch (InstantiationException | IllegalAccessException | ClassNotFoundException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
  String user = "root";
  String password = "root";
  String url = "jdbc:mysql://localhost:3306/t_user?&useSSL=false&allowPublicKeyRetrieval=true&serverTimezone=UTC";
  Connection connection = null;
  try {
   //2 创建链接对象connection
    connection = DriverManager.getConnection(url,user,password);
  } catch (SQLException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
  return connection;
 }
 
 //关闭资源的方法
 public static void close(Connection connection ) {
  try {
   if (connection != null) {
    connection.close();
   }
   
  } catch (SQLException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
 }
 public static void close(PreparedStatement preparedStatement ) {
  try {
   if (preparedStatement != null) {
    preparedStatement.close();
   }
   
  } catch (SQLException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
 }
 public static void close(ResultSet resultSet ) {
  try {
   if (resultSet != null) {
    resultSet.close();
   }
   
  } catch (SQLException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
 }
 
}

 

UserException.java

 

package com.jaovo.msg.Util;

@SuppressWarnings("serial")
public class UserException extends RuntimeException{

 public UserException() {
  super();
  // TODO Auto-generated constructor stub
 }

 public UserException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace) {
  super(message, cause, enableSuppression, writableStackTrace);
  // TODO Auto-generated constructor stub
 }

 public UserException(String message, Throwable cause) {
  super(message, cause);
  // TODO Auto-generated constructor stub
 }

 public UserException(String message) {
  super(message);
  // TODO Auto-generated constructor stub
 }

 public UserException(Throwable cause) {
  super(cause);
  // TODO Auto-generated constructor stub
 }
 
}

 

ValidateUtil.java

 

package com.jaovo.msg.Util;

import java.util.HashMap;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;

public class ValidateUtil {
 public static  boolean validateNull(HttpServletRequest request,String[] fileds) {
  boolean validate = true;
  //map对象用来装载不同的错误信息
  Map<String,String> errorMsg = new HashMap<String, String>();
  for(String filed :fileds) {
   String value = request.getParameter(filed);
   if (value == null || "".equals(value.trim())) {
    validate = false;
    errorMsg.put(filed, filed+"不能为空");
   }
   if (!validate) {
    request.setAttribute("errormsg", errorMsg);
   }
   
  }
  
  return validate;
 }
 public static String showError(HttpServletRequest request , String filed) {
  @SuppressWarnings("unchecked")
  Map<String, String> errorMsg = (Map<String,String>)request.getAttribute("errormsg");
  if (errorMsg == null) {
   return "";
  }
  String msg = errorMsg.get(filed);
  if (msg == null) {
   return "";
  }
  return msg;
 }
 
}

 

User.java

 

package com.jaovo.msg.model;

public class User {
 
 private int id;
 private String  name;
 private String  time;
 private String  jieci;
 private String  college;
 private String  tid;
 private String  tname;
 private String  number;
 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 getTime()
 {
  return time;
 }
 public void setTime(String time)
 {
  this.time = time;
 }
 public String getJieci()
 {
  return jieci;
 }
 public void setJieci(String jieci)
 {
  this.jieci = jieci;
 }
 public String getCollege()
 {
  return college;
 }
 public void setCollege(String college)
 {
  this.college = college;
 }
 public String getTid()
 {
  return tid;
 }
 public void setTid(String tid)
 {
  this.tid = tid;
 }
 public String getTname()
 {
  return tname;
 }
 public void setTname(String tname)
 {
  this.tname = tname;
 }
 public String getNumber()
 {
  return number;
 }
 public void setNumber(String number)
 {
  this.number = number;
 }

 
}

 

CharFilter.java

package com.jaovo.msg.filter;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

public class CharFilter implements Filter{
 String encoding = null;
 @Override
 public void init(FilterConfig filterConfig) throws ServletException{
  encoding = filterConfig.getInitParameter("encoding");
 }

 

 @Override
 public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
   throws IOException, ServletException {
//   request.setCharacterEncoding("utf-8");
   request.setCharacterEncoding(encoding);
   chain.doFilter(request, response);
 }

 public void destroy() {
  // TODO Auto-generated method stub
  System.out.println();
 }
}

 

IUserDao.java

 

package com.jaovo.msg.dao;

import java.util.List;

import com.jaovo.msg.model.User;

public interface IUserDao {
 public void add(User user);
 public void delete(int id);
 public void update(User user);
 public User load(int id);
 public User load(String name);
 public List<User> load();
 
}

 

UserDaoImpl.java

 

package com.jaovo.msg.dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import com.jaovo.msg.Util.DBUtil;
import com.jaovo.msg.Util.UserException;
import com.jaovo.msg.model.User;

 

public class UserDaoImpl implements IUserDao {

 //增
 public void add(User user) {
  //获得链接对象
  Connection connection = DBUtil.getConnection();
  //准备sql语句
  String sql = "select count(*) from class where name = ?";
 
  //创建语句传输对象
  PreparedStatement preparedStatement = null;
  ResultSet resultSet = null;
  try {
   preparedStatement = connection.prepareStatement(sql);
   preparedStatement.setString(1, user.getName());
   //接收结果集
   resultSet = preparedStatement.executeQuery();
   //遍历结果集
   while(resultSet.next()) {
    if (resultSet.getInt(1) > 0) {
     throw new UserException("用户已存在") ;
    }
   }
   
   sql = "insert into class(name,time,jieci,college,tid,tname,number) value (?,?,?,?,?,?,?)";
   preparedStatement = connection.prepareStatement(sql);
   //添加
   preparedStatement.setString(1, user.getName());
   preparedStatement.setString(2, user.getTime());
   preparedStatement.setString(3, user.getJieci());
   preparedStatement.setString(4, user.getCollege());
   preparedStatement.setString(5, user.getTid());
   preparedStatement.setString(6, user.getTname());
   preparedStatement.setString(7, user.getNumber());
   preparedStatement.executeUpdate();
  } catch (SQLException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }finally {
   //关闭资源
   DBUtil.close(resultSet);
   DBUtil.close(preparedStatement);
   DBUtil.close(connection);
  }
  
 }

 //删
 public void delete(int id) {
  //获得链接对象
  Connection connection = DBUtil.getConnection();
  String sql = "delete from class where id = ?";
  PreparedStatement preparedStatement = null;

  try {
   preparedStatement = connection.prepareStatement(sql);
   preparedStatement.setInt(1, id);
   preparedStatement.executeUpdate();
  } catch (SQLException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }finally {
   DBUtil.close(preparedStatement);
   DBUtil.close(connection);
  }
  
 }

 //改
 @Override
 public void update(User user) {
  //获得链接对象
  Connection connection = DBUtil.getConnection();
  //准备sql语句
  String sql = "update class set time = ? , jieci=? , college=? , tid=? , tname=? , number=? where id = ?";
  //创建语句传输对象
  PreparedStatement preparedStatement = null;
  try {
   preparedStatement = connection.prepareStatement(sql);
   preparedStatement.setString(1, user.getTime());
   preparedStatement.setString(2, user.getJieci());
   preparedStatement.setString(3, user.getCollege());
   preparedStatement.setString(4, user.getTid());
   preparedStatement.setString(5, user.getTname());
   preparedStatement.setString(6, user.getNumber());
   preparedStatement.setInt(7, user.getId());
   preparedStatement.executeUpdate();
  } catch (SQLException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }finally {
   DBUtil.close(preparedStatement);
   DBUtil.close(connection);
  }
 }

 @Override
 public User load(int id) {
  //获得链接对象
  Connection connection = DBUtil.getConnection();
  //准备sql语句
  String sql = "select * from class  where id = ?";
  //创建语句传输对象
  PreparedStatement preparedStatement = null;
  ResultSet resultSet = null;
  User user = null;
  try {
   preparedStatement = connection.prepareStatement(sql);
   preparedStatement.setInt(1, id);
   resultSet = preparedStatement.executeQuery();
   while(resultSet.next()) {
    user = new User();
    user.setId(id);
    user.setName(resultSet.getString("name"));
    user.setTime(resultSet.getString("time"));
    user.setJieci(resultSet.getString("jieci"));
    user.setCollege(resultSet.getString("college"));
    user.setTid(resultSet.getString("tid"));
    user.setTname(resultSet.getString("tname"));
    user.setNumber(resultSet.getString("number"));
   }
  } catch (SQLException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }finally {
   DBUtil.close(resultSet);
   DBUtil.close(preparedStatement);
   DBUtil.close(connection);
  }
  return  user;
 }

 @Override
 public User load(String name) {
  // TODO Auto-generated method stub
  return null;
 }

 @Override
 public List<User> load() {
  Connection connection = DBUtil.getConnection();
  //准备sql语句
  String sql = "select * from class ";
  //创建语句传输对象
  PreparedStatement preparedStatement = null;
  ResultSet resultSet = null;
  //集合中只能放入user对象
  List<User> users = new ArrayList<User>();
  User user = null;
  try {
   preparedStatement = connection.prepareStatement(sql);
   resultSet = preparedStatement.executeQuery();
   while(resultSet.next()) {
    user = new User();
    user.setId(resultSet.getInt("id"));
    user.setName(resultSet.getString("name"));
    user.setTime(resultSet.getString("time"));
    user.setJieci(resultSet.getString("jieci"));
    user.setCollege(resultSet.getString("college"));
    user.setTid(resultSet.getString("tid"));
    user.setTname(resultSet.getString("tname"));
    user.setNumber(resultSet.getString("number"));
    users.add(user);
   }
  } catch (SQLException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }finally {
   DBUtil.close(resultSet);
   DBUtil.close(preparedStatement);
   DBUtil.close(connection);
  }
  return  users;
 }

}

 

这就是完整的课程管理系统，增删改查