JAVA获取月第一天、最后一天

SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");	//获取前一个月的第一天	Calendar cal_1=Calendar.getInstance();//获取当前日期 	cal_1.add(Calendar.MONTH, -1);	cal_1.set(Calendar.DAY_OF_MONTH,1);//设置为1号,当前日期既为本月第一天 	String firstDay = format.format(cal_1.getTime());	System.out.PRintln("firstDay:"+firstDay); 	//获取前一个月的最后一天	Calendar cale = Calendar.getInstance(); 	cale.set(Calendar.DAY_OF_MONTH,0);//设置为1号,当前日期既为本月第一天 	String lastDay = format.format(cale.getTime());	System.out.println("lastDay:"+lastDay);	//获取当前月第一天：	Calendar c = Calendar.getInstance(); 	c.add(Calendar.MONTH, 0); 	c.set(Calendar.DAY_OF_MONTH,1);//设置为1号,当前日期既为本月第一天 	String first = format.format(c.getTime()); 	System.out.println("first:"+first); 	//获取当前月最后一天 	Calendar ca = Calendar.getInstance(); 	ca.set(Calendar.DAY_OF_MONTH, 	ca.getActualMaximum(Calendar.DAY_OF_MONTH));	String last = format.format(ca.getTime()); 	System.out.println("last:"+last);