Java 获取月未日期的步骤和對比

Java 获取月未日期的方法和對比

 

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

public class Test {
	public static void main(String[] args) throws Throwable {
		Test test = new Test();
		System.out.println(test.getStartDay());
		System.out.println(test.getDefaultDay());
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
		System.out.println(sdf.format(test.getStartDay()));
		System.out.println(sdf.format(test.getDefaultDay()));
		System.out.println(test.getStartDay().before(test.getDefaultDay()));
		System.out.println(test.getStartDay().after(test.getDefaultDay()));
	}

	public Date getStartDay() throws Throwable {
		String str = "2011-12-2";
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
		Calendar lastDate = Calendar.getInstance();
		lastDate.setTime(sdf.parse(str));
		return sdf.parse(str);
	}

	public Date getDefaultDay() throws Throwable {
		String str = "2011-12-2";
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
		Calendar lastDate = Calendar.getInstance();
		lastDate.setTime(sdf.parse(str));
		lastDate.set(Calendar.DATE, 1);// 设为当前月的1 号
		lastDate.add(Calendar.MONTH, 1);// 加一个月，变为下月的1 号
		lastDate.add(Calendar.DATE, -1);// 减去一天，变为当月最后一天
		return lastDate.getTime();
	}
}

 結果：

 

Fri Dec 02 00:00:00 CST 2011
Sat Dec 31 00:00:00 CST 2011
2011-12-02
2011-12-31
true
false