Javaはある年のある月の初日を取得します

/**
 * @Title:FisrtDayOfMonth.java
 * @Package:com.you.freemarker.model
 * @Description:          
 * @author:Youhaidong(   )
 * @date:2014-5-29   11:21:31
 * @version V1.0
 */
package com.you.freemarker.model;

import java.text.SimpleDateFormat;
import java.util.Calendar;

/**
 *      
 *          
 *     
 * <p>Title:FisrtDayOfMonth.java</p>
 * <p>Description:       </p>
 * <p>Copyright:Copyright(c)2013</p>
 * @author:   
 * @date:2014-5-29   11:21:31
 * @version V1.0
 */
public class FisrtDayOfMonth 
{

	/**
	 *           
	 * @Title:getFisrtDayOfMonth
	 * @Description:
	 * @param:@param year
	 * @param:@param month
	 * @param:@return
	 * @return:String
	 * @throws
	 */
	public static String getFisrtDayOfMonth(int year,int month)
	{
		Calendar cal = Calendar.getInstance();
		//    
		cal.set(Calendar.YEAR,year);
		//    
		cal.set(Calendar.MONTH, month-1);
		//        
		int firstDay = cal.getActualMinimum(Calendar.DAY_OF_MONTH);
		//            
		cal.set(Calendar.DAY_OF_MONTH, firstDay);
		//     
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
		String firstDayOfMonth = sdf.format(cal.getTime());
		
		return firstDayOfMonth;
	}

	/**
	 * @Title:main
	 * @Description:
	 * @param:@param args
	 * @return: void
	 * @throws
	 */
	public static void main(String[] args) 
	{
        String firstDay = getFisrtDayOfMonth(2014,5);
        System.out.println("          ：" + firstDay);
	}

}

          ：2014-05-01