Java：String和Date、Timestamp之间的转换

package Test;

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

public class Test1 {
    public static void main(String[] args) {
        Test1 t1=new Test1();
        t1.action1();
        t1.action2();
        t1.action3();
        t1.action4();
        t1.action5();
        t1.action6();
        
    }
    
    // String -> Date
    public void action1(){
        String dateStr = "2010/05/04 12:34:23";
        Date date = new Date();
        //注意format的格式要与日期String的格式相匹配
        DateFormat sdf = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
        try {
            date = sdf.parse(dateStr);
            System.out.println(date.toString());
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    //  Date -> String 日期向字符串转换，可以设置任意的转换格式format
        public void action2(){
            String dateStr = "";
            Date date = new Date();
            //format的格式可以任意
            DateFormat sdf = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
            DateFormat sdf2 = new SimpleDateFormat("yyyy-MM-dd HH/mm/ss");
            try {
                dateStr = sdf.format(date);
                System.out.println(dateStr);
                dateStr = sdf2.format(date);
                System.out.println(dateStr);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        
    //  String ->Timestamp  注：String的类型必须形如： yyyy-mm-dd hh:mm:ss[.f...] 这样的格式，中括号表示可选，否则报错！！！
            public void action3(){
                Timestamp ts = new Timestamp(System.currentTimeMillis());
                String tsStr = "2011-05-09 11:49:45";
                try {
                    ts = Timestamp.valueOf(tsStr);
                    System.out.println(ts);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
            
        //  Timestamp -> String 使用Timestamp的toString()方法或者借用DateFormat
                    public void action4(){
                        Timestamp ts = new Timestamp(System.currentTimeMillis());
                        String tsStr = "";
                        DateFormat sdf = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
                        try {
                            //方法一
                            tsStr = sdf.format(ts);
                            System.out.println(tsStr);
                            //方法二
                            tsStr = ts.toString();
                            System.out.println(tsStr);
                        } catch (Exception e) {
                            e.printStackTrace();
                        }
                    }
                //  Timestamp -> Date
                    public void action5(){
                        Timestamp ts = new Timestamp(System.currentTimeMillis());
                        Date date = new Date();
                        try {
                            date = ts;
                            System.out.println(date);
                        } catch (Exception e) {
                            e.printStackTrace();
                        }
                    }
                //  Date -> Timestamp
                    public void action6(){
                        Date time = new Date();
                        Timestamp dateTime = new Timestamp(time.getTime());
                        System.out.println(dateTime);
                    }
}