showselectcourse.java

网上选课系统

package student;
import java.io.*;
import java.text.*;
import java.util.*;
import java.sql.*; 
import java.net.*;
public class ShowSelectCourse{
	private String[] ID;
	private String SID;
	private String semester;
	private ResultSet se;
	Connection con =null;
	
	public void setID(String[] ID){
	    this.ID=ID;
	}
	
	public void setSID(String SID){
		this.SID=SID;
	}
	
	public void setSemester(String semester){
		this.semester=semester;
	}
	
	public ResultSet getSelect(){
		String sql;
		String []s=new String[10];
		try{
			String ss=getClass().getResource("/").getPath();
            String ss1=ss.substring(1).replace("%20"," ");
            URL str=getClass().getResource("/");
		
		    String s0=str.toString();
            String url0=s0.substring(6);
            String url=url0.replace("%20"," ");
		
		    String constr="jdbc:odbc:Driver={Microsoft Access Driver (*.mdb)};"+
    "DBQ="+url+"/data/system";
    
			Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
	        con = DriverManager.getConnection(constr);
	        Statement smt = con.createStatement();
	        sql="select * from Student_Course where semester='"+semester+"' and S_ID='"+SID+"'";
	        se=smt.executeQuery(sql);
	        int leng=0;
	        while(se.next())
	        {
	        	s[leng++]=String.valueOf(se.getInt(2));
	        }
	        for(int i=0;i<ID.length;i++)
	        {
	        	int j=0;
	        	for(;j<leng;j++)
	        	{
	        		if(ID[i].equals(s[j]))
	        		      break;
	        	}
	        	if(j>=leng)
	        	{
	        		sql="insert into Student_Course(S_ID,C_ID,semester) values('"+SID+"',"+Integer.parseInt(ID[i])+",'"+semester+"')";
	        	    smt.executeUpdate(sql);
	        	}
	        }
	        sql = "select * from Course where semester='"+semester+"' and Course.C_ID in (select Student_Course.C_ID from Student_Course where S_ID='"+SID+"')";
	        se=smt.executeQuery(sql);
		}
		catch(SQLException e)
		{
			se=null;
		}	
		finally{
			return  se;
		}    
	}
	
	 public void Close(){
		try{
			con.close();
		}
		catch(Exception e){
			
		}
	}
}