dateutils.java

J2EE项目开发Excel数据导入导出操作组件源代码（附带说明文档）

package com.javayjm.excel.util;

import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

/*＊
 * 公　司：
 * 文件名：DateUtils.java
 * 作　者：YJM
 * 版本号：1.0
 * 时　间：2007-11-3下午04:53:42
 */

public class DateUtils {
	private static String defaultPattern = "yyyy-MM-dd";
	/**
	 * 根据pattern判断字符串是否为合法日期
	 * 
	 * @param dateStr
	 * @param pattern
	 * @return 
	 */
	public static boolean isValidDate(String dateStr, String pattern) {
		boolean isValid = false;
		String patterns = "yyyy-MM-dd,MM/dd/yyyy";
		
		
		if (pattern == null || pattern.length() < 1) {
			pattern = "yyyy-MM-dd";
		}
		try {
			SimpleDateFormat sdf = new SimpleDateFormat(pattern);
			//sdf.setLenient(false);
			String date = sdf.format(sdf.parse(dateStr));
			if (date.equalsIgnoreCase(dateStr)) {
				isValid = true;
			}
		} catch (Exception e) {
			isValid = false;
		}
		//如果目标格式不正确，判断是否是其它格式的日期
		if(!isValid){
			isValid = isValidDatePatterns(dateStr,"");
		}
		return isValid;
	}
	public static boolean isValidDatePatterns(String dateStr,String patterns){
		if(patterns==null||patterns.length()<1){
			patterns = "yyyy-MM-dd;dd/MM/yyyy;yyyy/MM/dd;yyyy/M/d h:mm";
		}
		boolean isValid = false;
		String[] patternArr = patterns.split(";");
		for(int i=0;i<patternArr.length;i++){
			try {
				SimpleDateFormat sdf = new SimpleDateFormat(patternArr[i]);
				//sdf.setLenient(false);
				String date = sdf.format(sdf.parse(dateStr));
				if (date.equalsIgnoreCase(dateStr)) {
					isValid = true;
					DateUtils.defaultPattern = patternArr[i];
					break;
				}
			} catch (Exception e) {
				isValid = false;
			}
		}
		return isValid;
	}
	public static String getFormatDate(String dateStr, String pattern){
		if (pattern == null || pattern.length() < 1) {
			pattern = "yyyy-MM-dd";
		}
		try {
			SimpleDateFormat sdf = new SimpleDateFormat(DateUtils.defaultPattern);
			SimpleDateFormat format = new SimpleDateFormat(pattern);
			String date = format.format(sdf.parse(dateStr));
			return date;
		} catch (Exception e) {
			System.out.println("日期格转换失败！");
		}
		return null;
	}
	
	public static String getFormatDate(Date date,String pattern){
		if (pattern == null || pattern.length() < 1) {
			pattern = "yyyy-MM-dd";
		}
		try{
			SimpleDateFormat sdf = new SimpleDateFormat(pattern);
			String strDate = sdf.format(date);
			return strDate;
		}catch (Exception e) {
			System.out.println("日期格转换失败！");
		}
		return null;
	}
	public static void main(String[] args) {
		
//		boolean isd = DateUtils.isValidDate("08/09/2007", "yyyy-MM-dd");
//		if(isd){
//			String date = DateUtils.getFormatDate("08/09/2007", "yyyy-MM-dd");
//			System.out.println(date);
//		}
		//System.out.println(date);
		
		DateFormat df = DateFormat.getDateInstance();
		try {
			Date myDate = df.parse("2007-7-9");
			System.out.println(myDate.toString());
		} catch (ParseException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
	}
}