基本类型的转换如：int,double,long,string,Date,Calendar之间的转换

1、int转换成String
   int i = 123;
   String str = String.valueOf(i);

2、String转换成int
   String str = "123";
   int i = Integer.valueOf(str);或者Integer.parseInt(str);

3、double转换成String
   double d = 123.0d;
   String str = String.valueOf(d);

4、String转换成double
   String str = "123";
   double d = Double.valueOf(str);

3、long转换成String
   long l = 123.0l;
   String str = String.valueOf(l);

4、String转换成double
   String str = "123";
   long l = Double.valueOf(str);

5.Calendar 转化 String
Calendar calendat = Calendar.getInstance();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
String dateStr = sdf.format(calendar.getTime());

6.String 转化Calendar
String str="2013-07-31";
SimpleDateFormat sdf= new SimpleDateFormat("yyyy-MM-dd");
Date date =sdf.parse(str);
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);

7.Date 转化String
SimpleDateFormat sdf= new SimpleDateFormat("yyyy-MM-dd");
String dateStr=sdf.format(new Date());

8.String 转化Date
String str="2013-07-31";
SimpleDateFormat sdf= new SimpleDateFormat("yyyy-MM-dd");
Date date= sdf.parse(str);

9.Date 转化Calendar
Calendar calendar = Calendar.getInstance();
calendar.setTime(new java.util.Date());

10.Calendar转化Date
Calendar calendar = Calendar.getInstance();
java.util.Date date =calendar.getTime();