@JsonFormat(pattern="yyyy/MM/dd")
private Date createData;

    public String getCreateDate() {
        if (createDate == null) {
            return "";
        }
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy/MM/dd");
        return simpleDateFormat.format(createDate);
    }

    public void setAgreeDate(Date createDate) {
        this.createDate= createDate;
    }

package datetest;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.logging.Level;
import java.util.logging.Logger;

public class DataTest {

 
    public static void main(String[] args) {
      
        //将Date类型转成String类
       
        Date now=new Date();
        SimpleDateFormat dateFormat = new SimpleDateFormat("yyyyMMddHHmmss");
        String data=dateFormat.format(now);
       
        //将String类型转成Date类型
        String  mydate="2014/2/2 17:02:12";
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
        try {
            Date date=sdf.parse(mydate);
       
        } catch (ParseException ex) {
            Logger.getLogger(DataTest.class.getName()).log(Level.SEVERE, null, ex);
        }
    }
}