java 时间与字符串之间的转换

1. long字符串转换成yyyy-MM-dd HH:mm:ss格式输出

import java.text.SimpleDateFormat;
import java.util.Date;
//将long字符串转换成格式时间输出
public class LongToString {
public static void main(String argsp[]){
    String time="1256006105375";

    Date date=new Date(Long.parseLong(time));
    SimpleDateFormat formatter=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    time=formatter.format(date);
    System.out.println(time);
}
}

2. 字符串转换成时间

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

import ognl.ParseException;

public class StringToDate {
public static void main(String argsp[]) throws Exception{
    String time="2010-11-20 11:10:10";

    Date date=null;
    SimpleDateFormat formatter=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    date=formatter.parse(time);
    System.out.println(date);
}
}

3. 取得当前系统时间，返回yyyy-MM-dd HH:mm:ss字符串

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

public class StringToDate {
public static void main(String argsp[]) throws Exception{
    
    Date date=new Date();
    SimpleDateFormat formatter=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    String time=formatter.format(date);
    System.out.println(time);
}
}

4. 取得当前系统时间，返回 HH:mm:ss字符串

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

public class StringToDate {
public static void main(String argsp[]) throws Exception{
    
    Date date=new Date();
    SimpleDateFormat formatter=new SimpleDateFormat("HH:mm:ss");
    String time=formatter.format(date);
    System.out.println(time);
}
}

5.将20101125102503转换成2010-11-25 10:25:03输出

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

public class StringToDate {
public static void main(String argsp[]) throws Exception{
    
    String time="20101125102503";
    SimpleDateFormat formatter1=new SimpleDateFormat("yyyy-HH-dd HH:mm:ss");
    SimpleDateFormat formatter2=new SimpleDateFormat("yyyyHHddHHmmss");
    time=formatter1.format(formatter2.parse(time));
    System.out.println(time);
}
}