java字符串类型和时间类型的转换

类型转换

 //reqeust.getParameter获取字符串直接赋值
 1  public static Date date(String date_str) {
 2         try {
 3              Calendar zcal = Calendar.getInstance();//日期类
 4             Timestamp timestampnow = new Timestamp(zcal.getTimeInMillis());//转换成正常的日期格式
 5             SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");//改为需要的东西
 6              ParsePosition pos = new ParsePosition(0);
 7             java.util.Date current = formatter.parse(date_str, pos);
 8              timestampnow = new Timestamp(current.getTime());
 9            return timestampnow;
10          }
11          catch (NullPointerException e) {
12              return null;
13         }
14    }

 1 //Date类型转换成String类型
 2  public static String toJson(Object obj){
 3        String reuqest=null;
 4         //对象映射
 5          ObjectMapper mapper=new ObjectMapper();
 6           //设置时间格式
 7          SimpleDateFormat dateFormat=new SimpleDateFormat("yyyy年MM月dd日");
 8           mapper.setDateFormat(dateFormat);
 9              try {
10                  reuqest=mapper.writeValueAsString(obj);
11              } catch (JsonProcessingException e) {
12                  // TODO Auto-generated catch block
13                 e.printStackTrace();
14             }
15         return reuqest;
16      }

//String类型转换成Date类型

 1 public static Date date(String date_str) {

 2         try {
 3             Calendar zcal = Calendar.getInstance();//日期类
 4             Timestamp timestampnow = new Timestamp(zcal.getTimeInMillis());//转换成正常的日期格式
 5             SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");//改为需要的东西
 6             ParsePosition pos = new ParsePosition(0);
 7             java.util.Date current = formatter.parse(date_str, pos);
 8             timestampnow = new Timestamp(current.getTime());
 9             return timestampnow;
10         }
11         catch (NullPointerException e) {
12             return null;
13         }
14     }