java - 更改 YYYY/MM/DD -> MM/DD/YYYY java

Question

我希望将日期格式更改为 MM/DD/YYYY，目前为 YYYY/MM/DD。

我尝试对其进行研究，但讽刺的是，情况总是相反。现在，有人可能会说尝试向后尝试从那里开始工作，但它不起作用。

我的类用于调用所有的东西:

import java.util.*;
import java.text.*;

class Driver {   
   public static void main (String[] args) {    
       Kid kid;
       Node list = new Node(); 

       kid = createKid("Lexie", 2.6, "11/5/2009"); 
       insertEnd(list, kid);
       kid = createKid ("Sally", 2.3, "4/8/2009"); 
       insertEnd(list, kid);
       kid = createKid ("Joe", 2.7, "6/16/2009");
       insertEnd(list, kid);
       kid = createKid ("Bob", 2.2, "1/16/2009");
       insertEnd(list, kid);
       kid = createKid ("Tom", 3.1, "8/16/2009");
       insertEnd(list, kid);
       printList(list);
   } //end main method

   public static Kid createKid(String name, double height, String date) {
       return new Kid(name, height, date);
   }

} //end class     


import java.util.*; 
import java.text.SimpleDateFormat;
import java.io.*;
class Kid {  
    String name; 
    double height; 
    GregorianCalendar bDay; 

    ...
    /**
     * Second constructor for kid
     * Setting instances to equal the constructors of this
     * @param 1: Setting n (aka name,   but it was taken) to equal the instance var of name
     * @param 2: Setting h (aka height, but it was taken) to equal the instance var of height
     * @param 3: Setting date to equal the instance var of bDay with some modifications
     */
    public Kid (String n, double h, String date) {
        StringTokenizer st = new StringTokenizer(date, "/");
        this.name = n;
        this.height = h;
        this.bDay = new GregorianCalendar(Integer.parseInt(st.nextToken()), 
        Integer.parseInt(st.nextToken()), Integer.parseInt(st.nextToken()));
    }

    /**
     * public String toString() { 
     * Converting Java language to English language
     */
    public String toString() {

        return (this.name + ", Height: " + this.height + "ft., Born: "
        +       this.bDay.get(Calendar.DATE) + "/" + this.bDay.get(Calendar.MONTH) 
        + "/" + this.bDay.get(Calendar.YEAR));

    }
} //end class 

顺便说一句，简单日期格式类和日期格式类我不熟悉并且尝试实现它们没有成功。

Answer 1

只需使用 SimpleDateFormat将字符串转换为日期。无需为痛苦的 Calendar API 烦恼。

String dateString = "2012/06/05";
Date date = new SimpleDateFormat("yyyy/MM/dd").parse(dateString);

请在整个代码中使用此 Date 对象。每当您需要向人类呈现 Date 对象时，只需使用另一个 SimpleDateFormat:

String dateString = new SimpleDateFormat("MM/dd/yyyy").format(date);