inforcomputejanpel.java

学生成绩管理系统

package myjava.javaSeries.java.compoent;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.sql.*;
public class InforComputeJanpel extends JPanel 
{
	private JLabel best =new JLabel("优  秀");
	private JLabel good =new JLabel("良  好");
	private JLabel jige =new JLabel("一 般");
	private JLabel notjige =new JLabel("不及格");
    private JTextField youxiu=new JTextField(10);
	private JTextField lianghao=new JTextField(10);
	private JTextField jigea=new JTextField(10);
	private JTextField bujige=new JTextField(10);
	private JPanel JPLabels =new JPanel();
    private JPanel JPDisplay=new JPanel();
	private JPanel JPconbine=new JPanel();
 //  JOptionPane.showMessageDialog(null,"表中无记录","关于数据库系统",JOptionPane.INFORMATION_MESSAGE);
	public InforComputeJanpel()
	{
      //建立放置标签的面板
	  JPLabels.setLayout(new GridLayout(4,1));
      best.setHorizontalAlignment(SwingConstants.CENTER);
      good.setHorizontalAlignment(SwingConstants.CENTER);
      jige.setHorizontalAlignment(SwingConstants.CENTER);
	  notjige.setHorizontalAlignment(SwingConstants.CENTER);

      JPLabels.add(best);
	  JPLabels.add(good);
	  JPLabels.add(jige);
	  JPLabels.add(notjige);

	   //建立放置显示结果的面板
      JPDisplay.setLayout(new GridLayout(4,1));
      JPDisplay.add(youxiu);
      JPDisplay.add(lianghao);
	  JPDisplay.add(jigea);
      JPDisplay.add(bujige);

	   //建立组合放置标签和文本框的面板
	  JPconbine.setLayout(new GridLayout(1,2));
      JPconbine.add(JPLabels);
      JPconbine.add(JPDisplay);

	  //把面板放置到框架中
	  this.setLayout(new GridLayout(1,1));
	  this.add(JPconbine);

	  try
		{
		   InforModelDB mydata=new InforModelDB();
		  String sqlst="select count(*) from students";
		  ResultSet rs1 =mydata.executeSelect(sqlst);
		  int Num=0;
			int row=0,row1=0,row2=0,row3=0;
			float result=0,result1=0,result2=0,result3=0;
		if(rs1.next())
			 Num=rs1.getInt(1);
		if(Num!=0){
		    //形成Select语句
		  String sqls="select score from students where score between 90 and 100";
		  ResultSet  rs=mydata.executeSelect(sqls);
		 while(rs.next())
			{
			 row++;
		 }
		 result=row*100/Num;
		 youxiu.setText(""+result+"%");
         youxiu.setEnabled(false);
         rs=null;
		 sqlst="select score from students where score between 75 and 89";
		 rs=mydata.executeSelect(sqlst);
		 while(rs.next())
			{
			 row1++;
		 }
		 result1=row1*100/Num;
		 lianghao.setText(""+result1+"%");
         lianghao.setEnabled(false);
		 sqlst="select score from students where score between 60 and 74";
		 rs=mydata.executeSelect(sqlst);
		 while(rs.next())
			{
			 row2++;
		 }
		 result2=row2*100/Num;
		 jigea.setText(""+result2+"%");
         jigea.setEnabled(false);
         rs=null;
		 sqlst="select score from students where score between 0 and 59";
		 rs=mydata.executeSelect(sqlst);
		 while(rs.next())
			{
			 row3++;
		 }
		 result3=row3*100/Num;
		 bujige.setText(""+result3+"%");
         bujige.setEnabled(false);
		  }
	else {JOptionPane.showMessageDialog(null,"表中无记录","关于数据库系统",JOptionPane.INFORMATION_MESSAGE);
	}
		}
      catch(SQLException ex){
				ex.printStackTrace();
	  }catch(ClassNotFoundException ex){
				 ex.printStackTrace();
	  }
	}
}