import java.text.DateFormat;
import java.text.SimpleDateFormat;
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DateFormat df = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
Date d = new Date(12436432737L);
String s = df.format(d); //将时间对象转换成字符串,按照("yyyy-MM-dd hh:mm:ss")格式
System.out.println(s);
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String s2 = "1994-8-29";
DateFormat df2 = new SimpleDateFormat("yyyy-MM-dd");
try {
Date d2 = df2.parse(s2); //将字符串转换成时间对象,字符串格式必须和("yyyy-MM-dd")相同,否则出现异常
System.out.println(d2);
} catch (ParseException e) {
e.printStackTrace();
}