标签：String rs setString 选课 系统 stmt public conn

package link;
import java.sql.*;
import java.util.*;
import org.apache.jasper.tagplugins.jstl.core.Out;
public class MyConnection 
{
    final String URL="jdbc:mysql://localhost:3306/test?&useSSL=false&serverTimezone=UTC";
    final String Name="root";
    final String Password="woshinidie668";
    private static String name;
    private static String password;
    private static String tpassword;
    private static String cname;
    private static int number;
    private static String sname;
    private static String ID;
    private static String sex;
    private static String course;
    private static String subject;
    private static String title;
    private static String Tname;
    private static String CID;
    private static int cnumber;
    private Connection con;
    private PreparedStatement stmt;
    private ResultSet rs;
    private PreparedStatement stmt1;
    private ResultSet rs1;
    private static String spassword;
    boolean a;
    public static String getCID()
    {
        return CID;
    }

    public static void setCID(String cID)
    {
        CID = cID;
    }

    public  static String getName()
    {
           return name;
    }

    public  static void setName(String name) 
    {
        MyConnection.name = name;
    }

    public static String getPassword() 
    {
        return password;
    }

    public  static void setPassword(String password)
    {
        MyConnection.password = password;
    }

    public static int getNumber() 
    {
        return number;
    }

    public static void setNumber(int number) 
        {
            MyConnection.number = number;
        }

    public static String getCname() 
        {
            return cname;
        }

    public static void setCname(String name)
        {
            cname = name;
        }

    public static String getTpassword()
        {
            return tpassword;
        }

    public static void setTpassword(String tpassword) 
        {
            MyConnection.tpassword = tpassword;
        }
        
    public static String getSname()
    {
        return sname;
    }

    public static void setSname(String sname) 
    {
        MyConnection.sname = sname;
    }

    public static String getID() 
    {
        return ID;
    }

    public static void setID(String iD)
    {
            ID = iD;
    }

    public static String getSex() 
    {
        return sex;
    }

    public static void setSex(String sex)
    {
        MyConnection.sex = sex;
    }

    public static String getCourse()
    {
        return course;
    }

    public static void setCourse(String class1)
    {
        course = class1;
    }

    public static String getSubject()
    {
        return subject;
    }

    public static void setSubject(String subject) 
    {
        MyConnection.subject = subject;
    }

    public static int getCnumber() 
    {
        return cnumber;
    }

    public static void setCnumber(int cnumber) 
    {
        MyConnection.cnumber = cnumber;
    }

    public static String getTname() 
    {
        return Tname;
    }

    public static void setTname(String tname) 
    {
        Tname = tname;
    }

    public static String getTitle()
    {
            return title;
    }

    public static void setTitle(String title) 
    {
        MyConnection.title = title;
    }
        
    public String getSpassword() 
    {
        return spassword;
    }

    public void setSpassword(String spassword)
     {
        this.spassword = spassword;
     }
                
    public boolean isA() 
     {
        return a;
     }

    public void setA(boolean a) 
     {
        this.a = a;
     }

    public Connection getConnection() throws Exception
    {
           if(con == null)
            {
                         // 指出连接数据库所需要的驱动程序
                         Class.forName("com.mysql.cj.jdbc.Driver");
                         System.out.println("数据库连接成功！");

                         // 建立与数据库之间的连接
                         con = DriverManager.getConnection(URL,Name,Password);
                         System.out.println("数据库连接成功！");             
             }
             return con;
     }

    public void TnameFind(Connection conn) throws SQLException
    {
    String sql1="select * from imteacher where 教师工号=?";
    stmt=conn.prepareStatement(sql1);
    stmt.setString(1,getID( ));
    rs=stmt.executeQuery( );
        while(rs.next())
        {
            setTname(rs.getString("教师姓名"));
        }
    }
           
    public void SnameFind(Connection conn) throws SQLException
    {
        String sql1="select * from imstudent where 学号=?";
        stmt=conn.prepareStatement(sql1);
        stmt.setString(1,getID( ));
        rs=stmt.executeQuery( );
        while(rs.next())
        {
            setSname(rs.getString("姓名"));
        }
    }
           
    public boolean FindName(Connection conn) throws SQLException
   {
        String sql1="select * from management where 姓名=?";
        stmt=conn.prepareStatement(sql1);
        stmt.setString(1,getName( ));
        rs=stmt.executeQuery( );
        while(rs.next( ))
        {
            setA(true);
            if(rs.getString("密码").equals(getPassword()))
            {
                return true;
            }
            else
            {
                return false;
            }
        }
        return false;
    }
           
    public void addStudent(Connection conn)
    {
        String sql="insert into imstudent (学号,姓名,性别,班级,专业) values (?,?,?,?,?)";
        try {
                stmt=conn.prepareStatement(sql);
                stmt.setString(1,getID( ));
                stmt.setString(2,getSname( ));
                stmt.setString(3,getSex( ));
                stmt.setString(4,getCourse( ));
                stmt.setString(5,getSubject( ));
                stmt.execute( );
            } 
        catch (SQLException e) 
            {
                // TODO 自动生成的 catch 块
                e.printStackTrace();
            }
               
    }
           
    public void teacherAdd(Connection conn) throws SQLException
    {
        String sql="insert into teacher (教师工号,密码) values (?,?)";
        stmt=conn.prepareStatement(sql);
        stmt.setString(1,getID( ));
        stmt.setString(2,getTpassword( ));
        stmt.execute();
    }
           
    public void studentAdd(Connection conn) throws SQLException
    {
        String sql="insert into student (学号,密码) values (?,?)";
        stmt=conn.prepareStatement(sql);
        stmt.setString(1,getID( ));
        stmt.setString(2,getSpassword( ));
        stmt.execute();
    }
           
    public void addTeacher(Connection conn)
    {
        String sql="insert into imteacher (教师工号,教师姓名,教师性别,教师所在学院,职称) values (?,?,?,?,?)";
        try {
                stmt=conn.prepareStatement(sql);
                stmt.setString(1,getID( ));
                stmt.setString(2,getTname( ));
                stmt.setString(3,getSex( ));
                stmt.setString(4,getCourse( ));
                stmt.setString(5,getSubject( ));
                stmt.execute( );
            } 
        catch (SQLException e) 
            {
                // TODO 自动生成的 catch 块
                e.printStackTrace();
            }   
    }
           
    public void courseAdd(Connection conn)
    {
        String sql="insert into course (课程编号,课程名称,人数上限,任课教师,选课人数) values (?,?,?,?)";
        try {
                stmt=conn.prepareStatement(sql);
                stmt.setString(1,getID( ));
                stmt.setString(2,getCname( ));
                stmt.setInt(3,getNumber( ));
                stmt.setString(4,getTname( ));
                stmt.setInt(5, 0);
                stmt.execute( );
            } 
        catch (SQLException e) 
            {
                // TODO 自动生成的 catch 块
                e.printStackTrace();
            }   
    }

    public boolean showCourse(Connection conn) throws SQLException
    {
        setA(false);
        String sql1="select * from course where 课程名称=?";
        stmt=conn.prepareStatement(sql1); 
        stmt.setString(1, getName( ));
        rs=stmt.executeQuery( );
        if(rs.next( ))
        {
            if(rs.getInt("选课人数")>=rs.getInt("人数上限"))
            {
                return false;
            }
            else
            {
            setA(true);
            setCID(rs.getString("课程编号"));
            setName(rs.getString("课程名称"));
            setNumber(rs.getInt("人数上限"));
            setTname(rs.getString("任课教师"));
            setCnumber(rs.getInt("选课人数"));
            return true;
            }
        }
        return true;
    }
           
    public void PasswordTset(PreparedStatement stmt) throws SQLException
    {
        stmt.setString(1,getTpassword( ));
        stmt.setString(2,getID( ));
        stmt.executeUpdate( );
    }
           
    public void PasswordSset(PreparedStatement stmt) throws SQLException
    {
        stmt.setString(1,getSpassword( ));
        stmt.setString(2,getID( ));
        stmt.executeUpdate( );
    }
               
    public boolean FindSname(Connection conn) throws SQLException
    {
        String sql1="select * from student where 学号=?";
        String sql="Update student set 密码=? where 学号=?";
        stmt=conn.prepareStatement(sql1); 
        stmt.setString(1,getID( ));
        rs=stmt.executeQuery( );
        while(rs.next( ))
        {
             if(rs.getString("密码").equals(""))
             {
                 stmt=conn.prepareStatement(sql);
                 PasswordSset(stmt);
                 break;
             }
        }
        rs.close( );
        stmt.close( );
        stmt1=conn.prepareStatement(sql1);
        stmt1.setString(1,getID( ));
        rs1=stmt1.executeQuery( );
        while(rs1.next( ))
        {
             setA(true);
             if(rs1.getString("密码").equals(getSpassword()))
             {
                 return true;
             }
             else
             {
                 return false;
             }
        }
        return false;
    }
           
    public boolean FindTname(Connection conn) throws SQLException
    {
        String sql1="select * from teacher where 教师工号=?";
        String sql="Update teacher set 密码=? where 教师工号=?";
        stmt=conn.prepareStatement(sql1); 
        stmt.setString(1,getID( ));
        rs=stmt.executeQuery( );
        while(rs.next( ))
        {
              if(rs.getString("密码").equals(""))
              {
                  stmt=conn.prepareStatement(sql);
                  PasswordTset(stmt);
                  break;
              }
        }
        rs.close( );
        stmt.close( );
        stmt1=conn.prepareStatement(sql1);
        stmt1.setString(1,getID( ));
        rs1=stmt1.executeQuery( );
        while(rs1.next( ))
        {
             setA(true);
             if(rs1.getString("密码").equals(getTpassword()))
             {
                 return true;
             }
             else
             {
                 return false;
             }
        }
        return false;
    } 
             
    public void SearchTname(Connection conn) throws SQLException
    {
        String sql1="select * from imteacher where 教师姓名=?";
        stmt=conn.prepareStatement(sql1);
        stmt.setString(1,getTname( ));
        rs=stmt.executeQuery( );
        while(rs.next( ))
        {
            setID(rs.getString("教师工号"));
            setTname(rs.getString("教师姓名"));
            setSex(rs.getString("教师性别"));
            setCourse(rs.getString("教师所在学院"));
            setSubject(rs.getString("职称"));
        }
    }
           
    public void SearchSname(Connection conn) throws SQLException
    {
        String sql1="select * from imstudent where 姓名=?";
        stmt=conn.prepareStatement(sql1);
        stmt.setString(1,getSname( ));
        rs=stmt.executeQuery( );
        while(rs.next( ))
        {
            setID(rs.getString("学号"));
            setTname(rs.getString("姓名"));
            setSex(rs.getString("性别"));
            setCourse(rs.getString("班级"));
            setSubject(rs.getString("专业"));
        }
    }
           
    public void UpdateTeacher(Connection conn) throws SQLException
    {
        String sql1="Update imteacher set 教师所在学院=?,职称=? where 教师工号=?";
        stmt=conn.prepareStatement(sql1);
        stmt.setString(1, getCourse( ));
        stmt.setString(2, getSubject( ));
        stmt.setString(3, getID( ));
        stmt.execute( );
    }
           
    public void UpdateStudent(Connection conn) throws SQLException
    {
        String sql1="Update imstudent set 班级=?,专业=? where 学号=?";
        stmt=conn.prepareStatement(sql1);
        stmt.setString(1, getCourse( ));
        stmt.setString(2, getSubject( ));
        stmt.setString(3, getID( ));
        stmt.execute( );
    }
           
    public void UpdateCourse(Connection conn) throws SQLException
    {
        int a;
        String sql="Update course set 选课人数=? where 课程名称=?";
        String sql1="select * from course where 课程名称=?";
        stmt=conn.prepareStatement(sql1);
        stmt.setString(1, getName( ));
        rs=stmt.executeQuery( );
        while(rs.next( ))
        {
            a=rs.getInt("选课人数");
            a++;
            setNumber(a);
            stmt1=conn.prepareStatement(sql);
            stmt1.setInt(1,a);
            stmt1.setString(2, getName( ));
            stmt1.execute( ); 
        }
    }
           
    public void AddImcourse(Connection conn) throws SQLException
    {
        String sql="select * from imstudent where 学号=?";
        String sql1="insert into imcourse (选课学生,学号,性别,班级,专业,课程) values(?,?,?,?,?,?)";
        stmt=conn.prepareStatement(sql);
        stmt.setString(1, getID( ));
        rs=stmt.executeQuery( );
        while(rs.next( ))
        {
            setSname(rs.getString("姓名"));
            setSex(rs.getString("性别"));
            setCourse(rs.getString("班级"));
            setSubject(rs.getString("专业"));
            stmt1=conn.prepareStatement(sql1);
            stmt1.setString(1, getSname( ));
            stmt1.setString(2, getID( ));
            stmt1.setString(3, getSex( ));
            stmt1.setString(4, getCourse( ));
            stmt1.setString(5, getSubject( ));
            stmt1.setString(6, getName( ));
            stmt1.execute( ); 
        }
     }
    
  
    public void ShowTeacher(Connection conn) throws SQLException
    {
         String sql="select * from imteacher where 教师姓名=?";
         stmt=conn.prepareStatement(sql);
         stmt.setString(1, getTname( ));
         rs=stmt.executeQuery( );
         while(rs.next( ))
         {
             setID(rs.getString("教师工号"));
             setSex(rs.getString("教师性别"));
             setCourse(rs.getString("教师所在学院"));
             setSubject(rs.getString("职称"));
         }
    }
    
    public boolean Judgement(Connection conn) throws SQLException
    {
          int i=0;
         String sql="select * from imcourse where 学号=?";
         stmt=conn.prepareStatement(sql);
         stmt.setString(1, getID( ));
         rs=stmt.executeQuery( );
         while(rs.next( ))
         {
             if(rs.getString("课程").equals(getName( )))
             {
                 i++;
             }
         }
         if(i<1)return true;
         else return false;
    }
    
    public void close()
    {
          try
          {
              rs.close();
          }
          catch(Exception e){}
          try
          {
              stmt.close();
          }catch(Exception e){}
          try
          {
              con.close();
          }catch(Exception e){}
    }
}

标签：String,rs,setString,选课,系统,stmt,public,conn
来源： https://www.cnblogs.com/liuyang-cn/p/14136221.html

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