jreplacedialog.java

本程序不仅实现了记事本基本的功能

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package jnotepad;

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

/**
 *
 * @author Administrator
 */
class JReplaceDialog extends JDialog implements ActionListener {

    public JReplaceDialog(Frame owner, JTextArea area) {
        super(owner, "查找", false);
        this.area = area;
        //this.setLayout(new FlowLayout());
        setLayout(null); //将Layout设为null
        label.setBounds(10, 10, 80, 25);
        txtfld.setBounds(90, 10, 250, 25);
        findbn.setBounds(345, 10, 120, 25);
        rlabel.setBounds(10, 40, 80, 25);
        rtxtfld.setBounds(90, 40, 250, 25);
        upper_lower.setBounds(10, 80, 150, 25);
        replaceone.setBounds(345, 40, 120, 25);
        replaceall.setBounds(345, 70, 120, 25);
        cancelbn.setBounds(345, 100, 120, 25);

        this.add(label);
        this.add(txtfld);
        this.add(findbn);
        this.add(rlabel);
        this.add(rtxtfld);
        this.add(replaceone);
        this.add(upper_lower);
        this.add(cancelbn);
        this.add(replaceall);
        this.addWindowListener(new WindowAdapter() {

            public void windowClosing(WindowEvent e) {
                JReplaceDialog.this.dispose();//!!!!!!!!
            }
        });
        
         txtfld.addKeyListener(new KeyAdapter() {

            public void keyReleased(KeyEvent e) {
                String str = txtfld.getText();
                if(!str.equals(""))
                {
                    findbn.setEnabled(true);
                    replaceone.setEnabled(true);
                    replaceall.setEnabled(true);
                }
                else
                {
                    findbn.setEnabled(false);
                    replaceone.setEnabled(false);
                    replaceall.setEnabled(false);
                }
            }
        });
        findbn.addActionListener(this);
        findbn.setEnabled(false);
        replaceone.addActionListener(this);
        replaceone.setEnabled(false);       
        replaceall.addActionListener(this);
        replaceall.setEnabled(false);
        cancelbn.addActionListener(this);
        upper_lower.addActionListener(this);
        this.setResizable(false);
        this.setBounds(500, 300, 500, 170);
        this.setVisible(true);
    }

    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == findbn) {
            findNext();
        }
        if (e.getSource() == cancelbn) {
            JReplaceDialog.this.dispose();
        }
        if (e.getSource() == upper_lower) {
            if (teller) {
                teller = false;
            } else {
                teller = true;
            }
        }
        if (e.getSource() == replaceone) {
            replaceNext();
        }
        if (e.getSource() == replaceall) {
            replaceAll();
        }
    }

    private void findNext() {
        String obj = txtfld.getText();
        String all = area.getText();
        int len = obj.length();
        int end = all.length();
        int start = area.getSelectionEnd();//从光标位置开始查找字符串

        start = (start == end) ? 0 : start;
        for (; start <= end - len; start++) {
            if (teller) {
                if (all.substring(start, start + len).equals(obj)) {//若找到查找字符串
                    area.setSelectionStart(start); //选中并显示字符串
                    area.setSelectionEnd(start + len);
                    return; //退出方法
                }
            } else if (all.substring(start, start + len).toLowerCase().equals(obj.toLowerCase())) {//若找到查找字符串
                area.setSelectionStart(start); //选中并显示字符串
                area.setSelectionEnd(start + len);
                return; //退出方法
            }
        }
        JOptionPane.showMessageDialog(this, "          找不到“" + obj +
                "”", "记事本", JOptionPane.INFORMATION_MESSAGE);
    }

    private void replaceNext() {
        String oldstr = txtfld.getText();
        String newstr = rtxtfld.getText();
        String selectedstr = area.getSelectedText();
        if(selectedstr!=null && selectedstr.equals(oldstr))
        {
            area.replaceRange(newstr, area.getSelectionStart(), area.getSelectionEnd());
            findNext();
        }
        else
            findNext();
    }

    private void replaceAll() {
        String oldstr = txtfld.getText();
        String newstr = rtxtfld.getText();
        String all = area.getText();
        int oldlen = oldstr.length();
        int newlen = newstr.length();
        int dlen = newlen - oldlen;
        int end = all.length();
        int start = 0;

        try{
        for (; start <= end - oldlen;end += dlen, start += newlen) {
            all = area.getText();
            if (teller) {
                if (all.substring(start, start + oldlen).equals(oldstr)) {//若找到查找字符串
                    area.replaceRange(newstr, start, start+oldlen);
                }
            } else if (all.substring(start, start + oldlen).toLowerCase().equals(oldstr.toLowerCase())) {//若找到查找字符串
                area.replaceRange(newstr, start, start+oldlen);
            }
        }
        }catch(Exception ex){}
    }
    private JLabel label = new JLabel("查找内容(N):");
    private JTextField txtfld = new JTextField(24);
    private JLabel rlabel = new JLabel("替  换  为(P):");
    private JTextField rtxtfld = new JTextField(24);
    private JButton findbn = new JButton("查找下一个(F)");
    private JButton replaceone = new JButton("替      换(R)");
    private JButton replaceall = new JButton("全部替换(A)");
    private JButton cancelbn = new JButton("取   消");
    private JCheckBox upper_lower = new JCheckBox("是否区分大小写(C)");
    JTextArea area = new JTextArea();
    boolean teller = false;
}