java 將yyyyMMddHHmmss轉化爲yyyy-MM-dd HH:mm:ss格式的字符串

思路很簡單：先轉化爲yyyyMMddHHmmss格式的Date類型，再格式化爲yyyy-MM-dd HH:mm:ss格式的字符串類型

import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;

public class ConsoleTest {	
	public static void main(String args[]) {		
		String str = "20200402150221";		
		DateFormat df1 = new SimpleDateFormat("yyyyMMddHHmmss");
		DateFormat df2 = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
		try {
			Date time1 = df1.parse(str);
			String time2 = df2.format(time1);
			System.out.println(time2);
		} catch (Exception e) {
			System.out.println(e.getMessage());
		}		
	}
}

轉化後結果2020-04-02 15:02:21