inquiry.java

编写一个简单的图书馆图书查询界面

import java.io.*;
import java.awt.*;
import java.awt.event.*;

import javax.swing.*;

//import frank.simpleLibrary.Book;
import frank.simpleLibrary.GUI_Inquiry;
import frank.simpleLibrary.GetResult;

public class Inquiry extends JFrame {
	//private ObjectInputStream input;
	private GUI_Inquiry ui;
	private JButton openButton, inquireButton;
	
	private File fn; 	
	//set up GUI
	public Inquiry() {
		super("图书查询");
		
		ui = new GUI_Inquiry(4); // 4 text fields;
		getContentPane().add(ui, BorderLayout.CENTER);
		
		//openButton set up
		openButton = ui.getDoTask1Button();
		openButton.setText("打开文件...");
		openButton.addActionListener(
			new ActionListener() {
				public void actionPerformed(ActionEvent e) {
					openFile();
				}
			}
		);
		//inquireButton set up
		inquireButton = ui.getDoTask2Button();
		inquireButton.setText("查询");
		inquireButton.setEnabled(false);
		inquireButton.addActionListener(
			new ActionListener() {
				public void actionPerformed(ActionEvent e) {
					searchBook();
				}
			}
		);
		//window set up
		addWindowListener(
			new WindowAdapter() {
				public void windowClosing(WindowEvent e) {
					System.exit(0);
				}
			}
		);
		
		setSize(400, 150);
		setVisible(true);
	} //end CreateLibrary constructor
	
	//user choose filename
	private void openFile() {
		//file dialog
		JFileChooser fc = new JFileChooser();
		fc.setFileSelectionMode(JFileChooser.FILES_ONLY);
		
		int result = fc.showSaveDialog(this);
		//cancel
		if(result == JFileChooser.CANCEL_OPTION)
			return;
		//get filename
		fn = fc.getSelectedFile();
		
		//deal with invalid filename
		if(fn == null || fn.getName().equals("")) {
			JOptionPane.showMessageDialog(this, "无效的文件名", "无效的文件名", JOptionPane.ERROR_MESSAGE);
			return;
		}

		inquireButton.setEnabled(true);
		
	}//end of openFile()
	
	public void searchBook() {
		String tit, auth;
		double prc_low, prc_high;
		
		String fieldValues[] = ui.getFieldValues();
		try {
			tit = fieldValues[GUI_Inquiry.TITLE];
			auth = fieldValues[GUI_Inquiry.AUTHOR];
			prc_low = fieldValues[GUI_Inquiry.PRICE_LOW].equals("")?
					0 : Double.parseDouble(fieldValues[GUI_Inquiry.PRICE_LOW]);
			prc_high = fieldValues[GUI_Inquiry.PRICE_HIGH].equals("")?
					0 : Double.parseDouble(fieldValues[GUI_Inquiry.PRICE_HIGH]);			
			//call GetResult
			new GetResult(tit, auth, prc_low, prc_high, fn);
		}
		//handle format exceptions
		catch(NumberFormatException fmE) {
			JOptionPane.showMessageDialog(this, "错误的数据类型", "错误", JOptionPane.ERROR_MESSAGE);
		}
	} //end addRecord
	
	//execute app;
	public static void main(String[] args) {
		new Inquiry();
	}	
}