浅谈JAVA时间日期处理函数

青旅半醒 2022-09-19 12:04 113阅读 0赞

本次测试的代码如下:

![None.gif][] package  date;  
![None.gif][]  
![None.gif][] import  java.text.DateFormat;  
![None.gif][] import  java.text.ParseException;  
![None.gif][] import  java.text.SimpleDateFormat;  
![None.gif][] import  java.util.Calendar;  
![None.gif][] import  java.util.Date;  
![None.gif][]  
![None.gif][] public   class  Date\_EA  
![ExpandedBlockStart.gif][]![ContractedBlock.gif][] ... \{  
![InBlock.gif][]  
![ExpandedSubBlockStart.gif][]![ContractedSubBlock.gif][]    /\*\* \*//\*\*  
![InBlock.gif][]     \* @param args  
![InBlock.gif][]     \* @throws Exception   
![ExpandedSubBlockEnd.gif][]     \*/  
![InBlock.gif][]    public static void main(String\[\] args) throws Exception  
![ExpandedSubBlockStart.gif][]![ContractedSubBlock.gif][]    ...\{  
![InBlock.gif][]          
![InBlock.gif][]        //获取当前时间  
![InBlock.gif][]        Date date = new Date();  
![InBlock.gif][]        System.out.println(date);  
![InBlock.gif][]        System.out.println(date.toString());  
![InBlock.gif][]          
![InBlock.gif][]        //获取当前时间的具体情况,如年,月,日,week,date,分,秒等  
![InBlock.gif][]        Calendar calendat = Calendar.getInstance();  
![InBlock.gif][]        System.out.println(calendat.get(Calendar.DAY\_OF\_MONTH));  
![InBlock.gif][]          
![InBlock.gif][]          
![InBlock.gif][]          
![InBlock.gif][]        //Calendar与java.util.Date的转换  
![InBlock.gif][]        Date date\_2 = calendat.getTime();  
![InBlock.gif][]        System.out.println(date\_2);  
![InBlock.gif][]          
![InBlock.gif][]        //java.util.Date 与 Calendar的转换  
![InBlock.gif][]        Calendar calender\_2 = Calendar.getInstance();  
![InBlock.gif][]        calender\_2.setTime(date\_2);  
![InBlock.gif][]        System.out.println(calender\_2.get(Calendar.MINUTE));  
![InBlock.gif][]          
![InBlock.gif][]          
![InBlock.gif][]          
![InBlock.gif][]        //时间的格式化  
![InBlock.gif][]        DateFormat dateFormate = SimpleDateFormat.getInstance();  
![InBlock.gif][]        System.out.println(dateFormate.format(date\_2));  
![InBlock.gif][]          
![InBlock.gif][]          
![InBlock.gif][]          
![InBlock.gif][]        //时间的格式化,SimpleDateFormate格式化时间的输出形式,转化为字符串形式  
![InBlock.gif][]        SimpleDateFormat simpleDateFormate = new SimpleDateFormat("yyyy-MM-dd");  
![InBlock.gif][]        System.out.println(simpleDateFormate.format(date\_2));  
![InBlock.gif][]          
![InBlock.gif][]        SimpleDateFormat simpleDateFormate\_2 = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");  
![InBlock.gif][]        System.out.println(simpleDateFormate\_2.format(date\_2));  
![InBlock.gif][]          
![InBlock.gif][]        //字符串转换为Date对象 必须与SimpleDateFormate对象形式相同  
![InBlock.gif][]        System.out.println("字符串转换为Date对象");  
![InBlock.gif][]        Date date\_4 = simpleDateFormate.parse("2007-1-1");  
![InBlock.gif][]        System.out.println(date\_4);  
![InBlock.gif][]        Date date\_3 = simpleDateFormate\_2.parse("2007-08-21 3:3:2");  
![InBlock.gif][]        System.out.println(date\_3);  
![InBlock.gif][]          
![InBlock.gif][]          
![InBlock.gif][]          
![InBlock.gif][]        //java.util.Date 与 java.sql.Date的转换  
![InBlock.gif][]        java.sql.Date sqlDate = new java.sql.Date(date.getTime());  
![InBlock.gif][]        System.out.println(sqlDate);  
![InBlock.gif][]        System.out.println(sqlDate.toString());  
![InBlock.gif][]          
![InBlock.gif][]          
![InBlock.gif][]        //valueOf(s) s - 表示 "yyyy-mm-dd" 形式的日期的 String 对象   
![InBlock.gif][]        java.sql.Date sqlDate\_2 = java.sql.Date.valueOf("2007-5-5");  
![InBlock.gif][]        System.out.println(sqlDate\_2);  
![InBlock.gif][]          
![InBlock.gif][]        //报错  
![ExpandedSubBlockStart.gif][]![ContractedSubBlock.gif][]        /\*\*//\*java.sql.Date sqlDate\_3 = java.sql.Date.valueOf("2007-5-5 00:00:00");  
![ExpandedSubBlockEnd.gif][]        System.out.println(sqlDate\_3);\*/  
![ExpandedSubBlockEnd.gif][]    \}  
![InBlock.gif][]  
![ExpandedBlockEnd.gif][]\}   
![None.gif][]

JAVA时间日期处理主要有如下几个类:

java.util.Date

java.sql.Date

java.text.DateFormat

java.text.SimpleDateFormat

java.util.Calendar

具体使用上面的代码有简单的介绍.格式化输出形式主要用SimpleDateFormat,获取具体的年或月或日或分或秒用Calendar,Date与String 的转换主要用SimpleDateFormat.

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