[Java练习]数据类型互相转换

package com.neusoft;

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

public class Main {

//整形，小数，字符串，时间相互转换

public static void main(String[] args) throws ParseException
{
// write your code here
//数字和字符串相互转换
Integer i= 100;
String str = i.toString();
System.out.println(str);

int j = 200;
str = String.valueOf(j);
System.out.println(str);

String strNum = "789";
Integer n = Integer.parseInt(strNum);
n++;
System.out.println(n);

int t = (int) n;
System.out.println(t);

//时间和字符串相互转换
Date d = new Date();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd:HH:mm:ss");
String strDate = sdf.format(d);
System.out.println(strDate);

String strDate2 = "2005-06-5";
SimpleDateFormat sdf2 = new SimpleDateFormat("yyyy-MM-dd");
Date date = sdf2.parse(strDate2);
System.out.println(date);

//日期的加减，使用日历对象Calendar
Calendar cal = Calendar.getInstance();
cal.setTime(date);
cal.add(Calendar.MONTH,2);
cal.add(Calendar.DATE,5);
cal.add(Calendar.DATE,-2);

Date date2 = cal.getTime();
SimpleDateFormat sdf3 = new SimpleDateFormat("yyyy-MM-dd");
String strdate2 = sdf3.format(date2);
System.out.println(strdate2);

//2016-11-02
}
}