本文實例講述了java實現變更文件查詢的方法。分享給大家供大家參考。具體如下：
自己經常發布包時需要查找那些文件時上次發包後更新的數據文件，所以寫了這個發布包，
拷貝輸出的命令，dos窗口下執行，
為啥不直接複製文件，因為java拷貝文件會修改文件最後修改日期，所以採用dos下的拷貝。
/* * * 更改所生成文件模板為* 窗口> 首選項> Java > 代碼生成> 代碼和註釋*/package com.cn.wangk.tools;import java.awt.BorderLayout;import java.awt.Color;import java.awt.Component;import java.awt.Container;import java.awt.FlowLayout;import java.awt.GridLayout;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.util. Calendar;import java.util.GregorianCalendar;import javax.swing.BorderFactory;import javax.swing.JButton;import javax.swing.JComboBox;import javax.swing.JFrame;import javax.swing.JPanel;/** *// ** * Bean to display a month calendar in a JPanel. Only works for the Western * calendar. * * @author Ian F. Darwin, http://www.darwinsys.com/ * @version $Id: Cal.java, v 1.5 2004/02/09 03:33:45 ian Exp $ */public class Cal extends JPanel{ /** *//** The currently-interesting year (not modulo 1900!) */ protected int yy; /* * *//** Currently-interesting month and day */ protected int mm, dd; /** *//** The buttons to be displayed */ protected JButton labs[][]; /** *//* * The number of day squares to leave blank at the start of this month */ protected int leadGap = 0; /** *//** A Calendar object used throughout */ Calendar calendar = new GregorianCalendar(); /** * //** Today's year */ protected final int thisYear = calendar.get(Calendar.YEAR); /** *//** Today's month */ protected final int thisMonth = calendar.get(Calendar.MONTH); /* * *//** One of the buttons. We just keep its reference for getBackground(). */ private JButton b0; /** *//** The month choice */ private JComboBox monthChoice; /** *// ** The year choice */ private JComboBox yearChoice; /** *//** * Construct a Cal, starting with today. */ Cal(){ super(); setYYMMDD(calendar.get(Calendar.YEAR), calendar .get(Calendar.MONTH), calendar.get(Calendar.DAY_OF_MONTH)); buildGUI(); recompute(); } /** *//** * Construct a Cal, given the leading days and the total days * * @exception IllegalArgumentException * If year out of range */ Cal(int year, int month, int today){ super(); setYYMMDD(year, month, today); buildGUI(); recompute(); } private void setYYMMDD(int year, int month, int today){ yy = year; mm = month; dd = today; } String[] months ={ "January", "February", "March", "April", "May", "June ", "July", "August", "September", "October", "November", "December" }; /** *//** Build the GUI. Assumes that setYYMMDD has been called. */ private void buildGUI(){ getAccessibleContext().setAccessibleDescription( "Calendar not accessible yet. Sorry!"); setBorder(BorderFactory.createEtchedBorder()); setLayout(new BorderLayout()); JPanel tp = new JPanel(); tp.add( monthChoice = new JComboBox()); for (int i = 0; i < months.length; i++) monthChoice.addItem(months[i]); monthChoice.setSelectedItem(months[mm]); monthChoice.addActionListener(new ActionListener( ){ public void actionPerformed(ActionEvent ae){ int i = monthChoice.getSelectedIndex(); if (i >= 0){ mm = i; // System.out.println("Month=" + mm); recompute() ; } } }); monthChoice.getAccessibleContext().setAccessibleName("Months"); monthChoice.getAccessibleContext().setAccessibleDescription( "Choose a month of the year"); tp.add(yearChoice = new JComboBox()); yearChoice .setEditable(true); for (int i = yy - 5; i < yy + 5; i++) yearChoice.addItem(Integer.toString(i)); yearChoice.setSelectedItem(Integer.toString(yy)); yearChoice.addActionListener (new ActionListener(){ public void actionPerformed(ActionEvent ae){ int i = yearChoice.getSelectedIndex(); if (i >= 0){ yy = Integer.parseInt(yearChoice.getSelectedItem() .toString()); // System.out.println("Year=" + yy); recompute(); } } }); add(BorderLayout.CENTER, tp); JPanel bp = new JPanel(); bp.setLayout(new GridLayout(7, 7 )); labs = new JButton[6][7]; // first row is days bp.add(b0 = new JButton("S")); bp.add(new JButton("M")); bp. add(new JButton("T")); bp.add(new JButton("W")); bp.add(new JButton("R")); bp.add(new JButton("F")); bp.add(new JButton("S")); ActionListener dateSetter = new ActionListener(){ public void actionPerformed(ActionEvent e){ String num = e.getActionCommand(); if (!num.equals("")){ // set the current day highlighted setDayActive(Integer.parseInt(num)); // When this becomes a Bean, you can // fire some kind of DateChanged event here. // Also, build a similar daySetter for day-of- week btns. } } }; // Construct all the buttons, and add them. for (int i = 0; i < 6; i++) for (int j = 0; j < 7; j++){ bp.add(labs [i][j] = new JButton("")); labs[i][j].addActionListener(dateSetter); } add(BorderLayout.SOUTH, bp); } public final static int dom[] ={ 31, 28, 31, 30, /**//* jan feb mar apr */ 31, 30, 31, 31, /**//* may jun jul aug */ 30, 31, 30, 31 /**// * sep oct nov dec */ }; /** *//** Compute which days to put where, in the Cal panel */ protected void recompute(){ // System.out.println("Cal::recompute: " + yy + ":" + mm + ":" + dd); if (mm < 0 || mm > 11) throw new IllegalArgumentException("Month " + mm + " bad, must be 0-11"); clearDayActive (); calendar = new GregorianCalendar(yy, mm, dd); // Compute how much to leave before the first. // getDay() returns 0 for Sunday, which is just right. leadGap = new GregorianCalendar(yy, mm, 1).get(Calendar.DAY_OF_WEEK) - 1; // System.out.println("leadGap = " + leadGap); int daysInMonth = dom[mm]; if (isLeap(calendar.get(Calendar.YEAR)) && mm > 1) ++daysInMonth; // Blank out the labels before 1st day of month for (int i = 0; i < leadGap; i++){ labs[0][i].setText(""); } // Fill in numbers for the day of month. for (int i = 1; i <= daysInMonth; i++){ JButton b = labs[(leadGap + i - 1) / 7][(leadGap + i - 1) % 7] ; b.setText(Integer.toString(i)); } // 7 days/week * up to 6 rows for (int i = leadGap + 1 + daysInMonth; i < 6 * 7; i++){ labs[(i) / 7][(i) % 7].setText(""); } // Shade current day, only if current month if (thisYear == yy && mm == thisMonth) setDayActive(dd); // shade the box for today // Say we need to be drawn on the screen repaint(); } /** *//** * isLeap() returns true if the given year is a Leap Year. * * "a year is a leap year if it is divisible by 4 but not by 100, except * that years divisible by 400 *are* leap years." -- Kernighan & Ritchie, * _The C Programming Language_, p 37. */ public boolean isLeap(int year){ if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0) return true; return false; } /** *//** Set the year, month, and day */ public void setDate(int yy, int mm, int dd){ // System.out.println("Cal::setDate"); this.yy = yy; this.mm = mm; // starts at 0, like Date this .dd = dd; recompute(); } /** *//** Unset any previously highlighted day */ private void clearDayActive(){ JButton b; // First un-shade the previously-selected square, if any if ( activeDay > 0){ b = labs[(leadGap + activeDay - 1) / 7][(leadGap + activeDay - 1) % 7]; b.setBackground(b0.getBackground()); b.repaint(); activeDay = -1; } } private int activeDay = -1; /** *//** Set just the day, on the current month */ public void setDayActive(int newDay){ clearDayActive(); // Set the new one if (newDay <= 0) dd = new GregorianCalendar().get(Calendar.DAY_OF_MONTH); else dd = newDay; // Now shade the correct square Component square = labs[(leadGap + newDay - 1) / 7][(leadGap + newDay - 1) % 7]; square.setBackground(Color.red); square.repaint(); activeDay = newDay; } /** *//** For testing, a main program */ public static void main( String[] av){ JFrame f = new JFrame("Cal"); Container c = f.getContentPane(); c.setLayout(new FlowLayout()); // for this test driver, hardcode 1995/02/10. c.add(new Cal(1995, 2 - 1, 10)); // and beside it, the current month. c.add(new Cal()); f.pack(); f.setVisible(true); }}希望本文所述對大家的java程序設計有所幫助。