Java代码中如何将字符串转换为日期格式呢?

字符串转Date

字符串转日期对象的实现思路:
    jdk8及以后的版本可使用DateTimeFormatter
	   否则使用SimpleDateFormat更改字符串  

字符串转换为LocalDateTime
使用DateTimeFormatter更改日期格式

package com.java265;
 
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
 
public class DateFormatExample1 {
 
	// date format 1
    private static final DateTimeFormatter dateFormatter 
		= DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.S");
	
	// date format 2
    private static final DateTimeFormatter dateFormatterNew 
		= DateTimeFormatter.ofPattern("EEEE, MMM d, yyyy HH:mm:ss a");
 
    public static void main(String[] args) {
 
        String date = "2022-02-5 00:00:00.0";
 
		// string to LocalDateTime
        LocalDateTime ldateTime = LocalDateTime.parse(date, dateFormatter);
 
        System.out.println(dateFormatter.format(ldateTime));
 
        // change date format
        System.out.println(dateFormatterNew.format(ldateTime));
    }
}

SimpleDateFormat修改Date 将String转换为Date并使用SimpleDateFormat更改日期格式

package com.java265;
 
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
public class SimpleDateFormatExample {
    private static final SimpleDateFormat sdf = 
			new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.S");
 
    private static final SimpleDateFormat sdfNew = 
			new SimpleDateFormat("EEEE, MMM d, yyyy HH:mm:ss a");
 
    public static void main(String[] args) {
        String dateString = "2022-02-05 00:00:00.0";
        try {
			// string to date
            Date date = sdf.parse(dateString);
            System.out.println(sdf.format(date));
            System.out.println(sdfNew.format(date));
        } catch (ParseException e) {
            e.printStackTrace();
        }
    }
}