query.java

学生成绩管理系统：能输入学科

package 学生考试成绩分析程序;

import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.io.*;
import java.util.*;

public class Query extends JFrame implements ActionListener
{   
  static  String number,course,score;
    JButton jbOk,jbExit;
    JTextField jtNumber,jtCourse,jtScore;
    JLabel jlNumber,jlCourse,jlScore;
    static int count=0;
    String s1=null,s2=null;
      static String[] score1;
      static String[] number1;
      static String[] name;
      static String[] score2;
      JComboBox jc;
      static String[] s;
      static String[] c;
      static  int ccount=0;
      int m;

    public Query(){
        
        try{
               BufferedReader input=new   BufferedReader(new FileReader("course.txt")); 
               String line=input.readLine();
                input.close();
                StringTokenizer ss=new StringTokenizer(line,"*");
                m=ss.countTokens();
               
               s=new String[m];
               c=new String[m/4];
              
               for(int i=0;ss.hasMoreTokens();i++){
                   s[i]=ss.nextToken();
               }
               for(int j=0,k=1;j<m;j++,k++){
                   if(k==2){
                      
                       c[ccount]=s[j];   
                       ccount++;
                       
                   }
                   if(k==4)
                       k=0;
                }
                 
               Object[] O=new Object[m/4];
               for(int i=0;i<m/4;i++)
                   O[i]=c[i];
               jc=new JComboBox(O);
              
          }
         catch(Exception e)
         {
             count=0;
             ccount=0;
             m=0;
             JOptionPane.showMessageDialog(null, "查找失败");
         }
        
    JPanel jpanel=new JPanel();
    JPanel jpLabel=new JPanel();
    JPanel jpTextFile=new JPanel();
    JPanel jpButton=new JPanel();
    jpButton.setLayout(new FlowLayout());
    jpLabel.setLayout(new GridLayout(3,1));
    jpanel.setLayout(new GridLayout(2,1));
    jpTextFile.setLayout(new GridLayout(3,1));
    jlNumber=new  JLabel("           学号");
    jlCourse =new  JLabel("           课程");
    jlScore=new  JLabel("            分数");
    jbOk =new JButton("确定");
    jbExit=new JButton("退出");
    jtNumber=new JTextField("");
    jtScore=new JTextField(" 输出成绩区 ");
    
    jpLabel.add(jlNumber) ;
    jpTextFile.add(jtNumber);
    jpTextFile.add(jc);
    jpLabel.add(jlScore);
    jpTextFile.add(jtScore);
    jpButton.add(jbOk);
    jpButton.add(jbExit);
    jbOk.addActionListener(this);
    jbExit.addActionListener(this);
    
    getContentPane().add(jpLabel,BorderLayout.WEST);
    getContentPane().add(jpButton,BorderLayout.SOUTH);
    getContentPane().add(jpTextFile,BorderLayout.CENTER);
    
     }
 
  public void actionPerformed(ActionEvent e)
  {
        if(e.getSource()==jbOk)
        {
          number =jtNumber.getText();
          course=jc.getSelectedItem().toString();
          jtScore.setText(find(number,course));
          count=0;
          ccount=0;
          m=0;
          
      }
     else if(e.getSource()==jbExit)
     {
         count=0;
          ccount=0;
          m=0;
         this.setVisible(false);
         
    }
     }
  public String find(String number,String course) 
  {
     

             try
             { 
                 
                     BufferedReader input1=new BufferedReader(new FileReader("score.txt"));
                     Boolean eof=false;
                     String line;
                     line=input1.readLine();
                     StringTokenizer tokenizer=new StringTokenizer(line,"*");
                     int n=tokenizer.countTokens();
                     score1=new String[n];
                     number1=new String[n/7];
                     name=new String[n/7];
                     score2=new String[n/7];
                     input1.close();
                      
                     for(int i=0;tokenizer.hasMoreTokens();i++)   
                     {
                         score1[i]=tokenizer.nextToken();
                     }
                     for(int j=0,k=1;j<n;j++,k++)
                     {
                         if(k==4){
                             number1[count]=score1[j-1];
                             name[count]=score1[j-2];
                             score2[count]=score1[j+1];
                             count++;  
                         }
                         if(k==7){
                             k=0;
                         }
                     }
                     
                     StringTokenizer scanner1=new StringTokenizer(course);
                     StringTokenizer scanner2=new StringTokenizer(number);
                     s1=scanner1.nextToken();
                     s2=scanner2.nextToken();
                     for(int i=0;i<count;i++)
                     {
                         if((s1.equals(name[i]))&&(s2.equals(number1[i])))
                         {
                         score= score2[i];
                         eof=true;
                     }
                     }
                     if(!eof)
                         score="没有找到符合条件的学生成绩";
             }
             catch(Exception e)
             {
                 count=0;
                 ccount=0;
                 m=0;
                 JOptionPane.showMessageDialog(null, "查找失败");
             }
             count=0;
             
             return score;
  }
  
    }