example8_6.java

《Java程序设计与应用》-张仕斌-源程序 《Java程序设计与应用》-张仕斌-源程序

/*
 * Example8_6.java
 *
 * Created on 2006年10月19日, 上午11:02
 */

package example8_6;
import java.io.*; 
import java.util.*;
import java.awt.*;
import java.applet.*;
import java.awt.event.*;

/**
 *
 * @author  Administrator
 */
public class Example8_6 extends Applet implements ActionListener
{
    
    /** Initializes the applet Example8_6 */
 /*   public void init() {
        try {
            java.awt.EventQueue.invokeAndWait(new Runnable() {
                public void run() {
                    initComponents();
                }
            });
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }*/
    private static final File INFO_FILE =new File("hqsj.txt");
    private Hashtable stockInfo;
    TextField stockID;
    Button button1;
    private String quoteid,quotename;
    public void init(){
        add(new Label("股票代码"));
        stockID = new TextField(6);
        add(stockID);
			button1 = new Button("查询");
			button1.addActionListener(this);
			add(button1);
			resize(500, 300);
    }
		public void start()
                {
                    loadinfo();
                }
		protected boolean loadinfo()
                {
			String fileLine;StringTokenizer tokenize;
			String id;StringBuffer name;
			try {
				// 创建一个访问数据文件的stream
				BufferedReader stockInput = new 
				BufferedReader(new FileReader(INFO_FILE));
				// 创建Hashtable对象
				stockInfo = new Hashtable();
				// 每次从文件中读一行数据
				while ((fileLine = stockInput.readLine()) != null)
                                {
					// 将每一行数据分解为tokens.
					tokenize = new StringTokenizer(fileLine);
					try {
						id = tokenize.nextToken();
						// 创建一个放置股票信息的buffer
						name = new StringBuffer();
						while(tokenize.hasMoreTokens())
                                                {
							name.append(tokenize.nextToken());
							if (tokenize.hasMoreTokens()){name.append("");}
						}
						// 向Hashtable中充填记录
						stockInfo.put(id,name.toString());
					} 
			catch(NullPointerException excpt){System.err.println("充填数据时出错：					" + excpt);}
		catch(NoSuchElementException excpt){System.err.println("无效的数据						记录 " +"in file: " + excpt);}
				} 
				stockInput.close();
			}
			catch(FileNotFoundException excpt) 
                        {
				System.err.println("不能发现文件: " + excpt);
				return false;
			} 
			catch(IOException excpt) 
                        {
				System.err.println("I/O故障: " + excpt);
				return false;
			}
 			return true;
                }
		protected String getQuote(String StockID)
                {
			String info; 
			// 从Hashtable得到数据
			info = (String)stockInfo.get(StockID);
			if (info != null) return info;
			else return "股票代码错误！";
		}
		public void paint(Graphics g)
                {
			g.drawString("股票代码"+quoteid+":" ,10,60);
			g.drawString("股票名称"+"前收"+"今开"+"最高"+"最低"+"收盘"+"交易量"+"						交易金额", 10, 90);
			g.drawString(quotename, 10, 120);
		}
		public void actionPerformed(ActionEvent ev)
                {
			String label = ev.getActionCommand();
			if (label.equals("查询"))
                        {
				quoteid = stockID.getText();
				if(quoteid != null) quotename = getQuote(quoteid);
				else quotename = "请输入股票代码！";
				repaint();
			}
                }
                
    
    /** This method is called from within the init() method to
     * initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is
     * always regenerated by the Form Editor.
     */
    // <editor-fold defaultstate="collapsed" desc=" Generated Code ">//GEN-BEGIN:initComponents
    private void initComponents() {
        
        setLayout(new java.awt.BorderLayout());
        
    }
    // </editor-fold>//GEN-END:initComponents
    
                
    // Variables declaration - do not modify//GEN-BEGIN:variables
    // End of variables declaration//GEN-END:variables
                }