Java在編寫一些圖形化的小程式時，有時也要去儲存少量的資料，如果用JDBC來串連資料庫，就會使程式速度減慢，而且及不方面，我們可以用Java中的檔案來代替資料庫儲存資料，這樣不但可以實現儲存的功能，而且不用考慮資料頻繁的存取，可以把檔案定義成為HTML檔案，並將儲存的資料以表格的方式顯示，這樣就可以直接在網頁中看到資料，下面是我寫的一個小的檔案儲存體資料的執行個體：
import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.sql.*;import java.io.*;import javax.swing.*;public class filework extends JFrame implements ActionListener { JPanel p; JButton b0,b1,b2; JTable tab; Object my[][] = new Object[50][3]; int a[]=new int[50]; int b[]=new int[50]; int j=0,rows=0; int k=0,shu=0; String name,age; String title[] = {"姓名", "年齡", "身高"}; BufferedReader in; int i = 0; public filework() { super("資料輪迴"); this.setSize(300, 300); this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); p = new JPanel(); tab = new JTable(my, title); b0 = new JButton("添加"); b1 = new JButton("開啟"); b2 = new JButton("儲存"); b1.addActionListener(this); b2.addActionListener(this); b0.addActionListener(this); p.add(b0); p.add(b1); p.add(b2); this.getContentPane().add(new JScrollPane(tab), "Center"); this.getContentPane().add(p, "South"); this.setVisible(true); } public void fileopen() { try{ JFileChooser choose=new JFileChooser("."); int sis=choose.showOpenDialog(this); String name=choose.getSelectedFile()+""; if(sis==JFileChooser.APPROVE_OPTION){ in=new BufferedReader(new FileReader(name)); String over=null; String line; while((line=in.readLine())!=null){ over=over+line; } for(int i=0;i<a.length;i++){ a[i]=over.indexOf("<td>")+4; b[i]=over.indexOf("</td>"); my[rows][k]=over.substring(a[i],b[i]); over=over.substring(b[i]+4,over.length()); k=k+1; if(k==3){k=0;rows=rows+1;} } } }catch(Exception ie){} } public static void main(String[] args) { filework filework = new filework(); } public void actionPerformed(ActionEvent e) { if (e.getSource() == b1) { fileopen(); } if (e.getSource() == b2) { JFileChooser save=new JFileChooser("."); int result=save.showSaveDialog(null); String s1=save.getSelectedFile()+""; if(result==JFileChooser.APPROVE_OPTION){ try { OutputStreamWriter out = new OutputStreamWriter(new FileOutputStream(s1)); String s2="<html><head></head><body>";s2=s2+"<table border=\"1\" width=\"50%\" bordercolor=\"green\" align=\"center\">"; s2=s2+"<tr>"; s2=s2+"<th>"+"姓名"+"</th>"; s2=s2+"<th>"+"年齡"+"</th>"; s2=s2+"<th>"+"身高"+"</th>"; s2=s2+"</tr>"; for(int shu=0;shu<rows;shu++) { s2=s2+"<tr align=\"center\">"; s2=s2+"<td>"+my[shu][0].toString().trim()+"</td>"; s2=s2+"<td>"+my[shu][1].toString().trim()+"</td>"; s2=s2+"<td>"+my[shu][2].toString().trim()+"</td>"; s2=s2+"</tr>"; } s2=s2+"</table></body></html>"; out.write(s2); out.close(); for(int i1=0;i1<50;i1++){ my[i1][0]=""; my[i1][1]=""; my[i1][2]=""; } rows=0; this.repaint(); JOptionPane.showMessageDialog(null,"儲存資料成功!","information",JOptionPane.QUESTION_MESSAGE); } catch (Exception ex1) { } } } if(e.getSource()==b0){ JTextField message[]=new JTextField[6]; message[0]=new JTextField("請輸入姓名："); message[0].setEditable(false); message[1]=new JTextField(); message[2]=new JTextField("請輸入年齡："); message[2].setEditable(false); message[3]=new JTextField(); message[4]=new JTextField("請輸入身高："); message[4].setEditable(false); message[5]=new JTextField(); String str[]={"確認","取消"}; int go=JOptionPane.showOptionDialog(null, message, "添加使用者",JOptionPane.YES_OPTION, JOptionPane.INFORMATION_MESSAGE, null, str, str[0]); if(go==0){ if(message[1].getText().equals("")&& message[3].getText().equals("")&& message[5].getText().equals("")){JOptionPane.showMessageDialog(null,"資料不可為空","ERROR",JOptionPane.ERROR_MESSAGE);} else{ my[rows][0]=message[1].getText(); my[rows][1]=message[3].getText(); my[rows][2]=message[5].getText(); this.repaint();rows=rows+1;} } } }}
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