java 日期操作辅助类

FormatDate.java

package com.ucit.ca.webApp.tool;

import java.util.*;
import java.text.*;

public class FormatDate {

	public FormatDate() {
	}

	// 格式化日期为字符串 "yyyy-MM-dd   hh:mm"
	public String formatDateTime(Date basicDate, String strFormat) {
		SimpleDateFormat df = new SimpleDateFormat(strFormat);
		return df.format(basicDate);
	}

	// 格式化日期为字符串 "yyyy-MM-dd   hh:mm"
	public String formatDateTime(String basicDate, String strFormat) {
		SimpleDateFormat df = new SimpleDateFormat(strFormat);
		Date tmpDate = null;
		try {
			tmpDate = df.parse(basicDate);
		} catch (Exception e) {
			// 日期型字符串格式错误
		}
		return df.format(tmpDate);
	}

	// 当前日期加减n天后的日期，返回String (yyyy-mm-dd)
	public String nDaysAftertoday(int n) {
		SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd");
		Calendar rightNow = Calendar.getInstance();
		// rightNow.add(Calendar.DAY_OF_MONTH,-1);
		rightNow.add(Calendar.DAY_OF_MONTH, +n);
		return df.format(rightNow.getTime());
	}

	// 当前日期加减n天后的日期，返回String (yyyy-mm-dd)
	public Date nDaysAfterNowDate(int n) {
		Calendar rightNow = Calendar.getInstance();
		// rightNow.add(Calendar.DAY_OF_MONTH,-1);
		rightNow.add(Calendar.DAY_OF_MONTH, +n);
		return rightNow.getTime();
	}

	// 给定一个日期型字符串，返回加减n天后的日期型字符串
	public String nDaysAfterOneDateString(String basicDate, int n) {
		SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd");
		Date tmpDate = null;
		try {
			tmpDate = df.parse(basicDate);
		} catch (Exception e) {
			// 日期型字符串格式错误
		}
		long nDay = (tmpDate.getTime() / (24 * 60 * 60 * 1000) + 1 + n)
				* (24 * 60 * 60 * 1000);
		tmpDate.setTime(nDay);

		return df.format(tmpDate);
	}

	// 给定一个日期，返回加减n天后的日期
	public Date nDaysAfterOneDate(Date basicDate, int n) {
		long nDay = (basicDate.getTime() / (24 * 60 * 60 * 1000) + 1 + n)
				* (24 * 60 * 60 * 1000);
		basicDate.setTime(nDay);

		return basicDate;
	}

	// 计算两个日期相隔的天数
	public int nDaysBetweenTwoDate(Date firstDate, Date secondDate) {
		int nDay = (int) ((secondDate.getTime() - firstDate.getTime()) / (24 * 60 * 60 * 1000));
		return nDay;
	}

	// 计算两个日期相隔的天数
	public int nDaysBetweenTwoDate(String firstString, String secondString) {
		SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd");
		Date firstDate = null;
		Date secondDate = null;
		try {
			firstDate = df.parse(firstString);
			secondDate = df.parse(secondString);
		} catch (Exception e) {
			// 日期型字符串格式错误
		}

		int nDay = (int) ((secondDate.getTime() - firstDate.getTime()) / (24 * 60 * 60 * 1000));
		return nDay;
	}

}

源码下载地址：

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