JavaWeb——课程管理系统（2）.java---18.11.29

时间：2019-01-23 13:56:54 阅读：199 评论：0 收藏：0 [点我收藏+]

标签：连接 ram otf lse ror 创建 pass value util

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

JavaWeb——课程管理系统（2）.java---18.11.29

标签：连接 ram otf lse ror 创建 pass value util

原文地址：https://www.cnblogs.com/mitang0-0/p/10308328.html

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