简易的学生课程成绩系统

				import java.util.*;
				import java.io.*;
				public class Import 
				{
				    public static void main(String args[])
				    {
				     try{
				        BufferedReader readfile = new BufferedReader(new FileReader("import.csv"));
				        RandomAccessFile writefile = new  RandomAccessFile("database.csv","rw"); 
				        String inputline1 = readfile.readLine();
				        String inputline2;   
				       while(inputline1!=null)
				       {
				           long pointer = writefile.getFilePointer();     
				           boolean b = true;
				           String []s = inputline1.trim().split(",");
				           while((inputline2=writefile.readLine()) !=null)
				          {
				             String [] line = inputline2.trim().split(",");
				             CompareString q0=new CompareString();
				             CompareString q1=new CompareString();
				             if((q0.compare(line[0],s[0])) && (q1.compare(line[1],s[1])))
				             {
				                 writefile.seek(pointer);
				                 writefile.write(inputline1.getBytes());
				                 b = false;
				                 break;
				              }
				              pointer = writefile.getFilePointer();
				           }
				           if(b == true)
				           {
				             writefile.write(inputline1.getBytes());
				             writefile.write('\n');
				           }  
				           inputline1 = readfile.readLine();
				        }
				        readfile.close();
				        writefile.close();
				     }
				     catch(FileNotFoundException e)
				    {
				       System.out.println("File not found");
				    }
				    catch(IOException e)
				    {
				       System.out.println("IO Exception");
				      
				      }
				    }
				}