java - 日期验证android java

Question

我的项目中有两个日期时间选择器，分别是开始日期和结束日期，
但是问题是说，如果我选择18/10/2014作为开始日期，结束日期是1/11/2014，则结束日期无效，因为第1天的日期无效，因为它小于第18天。为此

//start date
    TableRow r8 = new TableRow(this);
    TextView tvStartDate = new TextView(this);
    tvStartDate.setText("Start Date: ");
    final EditText etStartDate = new EditText(this);
    etStartDate.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            Calendar dateNow = Calendar.getInstance();
            int year = dateNow.get(Calendar.YEAR);
            int month = dateNow.get(Calendar.MONTH);
            int day = dateNow.get(Calendar.DAY_OF_MONTH);

            DatePickerDialog dp;
            dp = new DatePickerDialog(AddPetActivity.this, new OnDateSetListener() {
                public void onDateSet(DatePicker datepicker, int selectedyear, int selectedmonth, int selectedday) {
                    // TODO Auto-generated method stub
                    selectedmonth = selectedmonth + 1;
                    etStartDate.setText("" + selectedday + "/" + selectedmonth + "/" + selectedyear);
                }
            }, year, month, day);
            dp.setTitle("Select Date");
            dp.show();
        }
    });
    r8.addView(tvStartDate);
    r8.addView(etStartDate);
    tb.addView(r8);

    //end date
    TableRow r9 = new TableRow(this);
    TextView tvEndDate = new TextView(this);
    tvEndDate.setText("End Date: ");
    final EditText etEndDate = new EditText(this);
    etEndDate.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            Calendar dateNow = Calendar.getInstance();
            int year = dateNow.get(Calendar.YEAR);
            int month = dateNow.get(Calendar.MONTH);
            int day = dateNow.get(Calendar.DAY_OF_MONTH);

            DatePickerDialog dp;
            dp = new DatePickerDialog(AddPetActivity.this, new OnDateSetListener() {
                public void onDateSet(DatePicker datepicker, int selectedyear, int selectedmonth, int selectedday) {
                    // TODO Auto-generated method stub
                    selectedmonth = selectedmonth + 1;

                    etEndDate.setText("" + selectedday + "/" + selectedmonth + "/" + selectedyear);
                }
            }, year, month, day);
            dp.setTitle("Select Date");
            dp.show();
        }
    });
    r9.addView(tvEndDate);
    r9.addView(etEndDate);
    tb.addView(r9);

=========================================================================================

对于验证部分的开始日期和结束日期

else if (CheckDate(today, etStartDate.getText().toString()) == false)
                Toast.makeText(getApplicationContext(), "Invalid Start Date!", Toast.LENGTH_SHORT).show();

            else{
                if (!etEndDate.getText().toString().matches("")) {
                    if (CheckDate( etStartDate.getText().toString(), etEndDate.getText().toString()) == false)
                        Toast.makeText(getApplicationContext(), "Invalid End Date!", Toast.LENGTH_SHORT).show();


=========================================================================================

最后部分

private boolean CheckDate(String fromDate, String toDate)
{   
        SimpleDateFormat sdf = new SimpleDateFormat("dd/mm/yyyy");
        Date dateFrom = null;
        Date dateTo = null;
        try {
            dateFrom = sdf.parse(fromDate);
            dateTo = sdf.parse(toDate);
        } catch (ParseException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }   

    if (dateTo.after(dateFrom) == true) 
        return true; 
    else 
        return false;
}

Answer 1

要比较日期，请使用方法：：
这是一个简单的示例，您可以将其用作返回结果的方法

try{

            SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy"); //edit here
            Date date1 = sdf.parse("2009-12-31");
            Date date2 = sdf.parse("2010-01-31");

            System.out.println(sdf.format(date1));
            System.out.println(sdf.format(date2));

            if(date1.compareTo(date2)>0){
                System.out.println("Date1 is after Date2");
            }else if(date1.compareTo(date2)<0){
                System.out.println("Date1 is before Date2");
            }else if(date1.compareTo(date2)==0){
                System.out.println("Date1 is equal to Date2");
            }else{
                System.out.println("How to get here?");
            }

        }catch(ParseException ex){
            ex.printStackTrace();
        }

对于您的情况：

    private boolean CheckDate(String fromDate, String toDate)
   { 
   boolean result=false;
   try{

            SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy"); //edit here
            Date dateStart = sdf.parse(fromDate);
            Date dateEnd = sdf.parse(toDate);

            if(dateStart .compareTo(dateEnd)>0){
                System.out.println("dateStart is after dateEnd ");
                 result=false;
            }else if(dateStart .compareTo(dateEnd)<0){
                 System.out.println("dateStart is before dateEnd ");
                 result=true;
            }else if(dateStart .compareTo(dateEnd)==0){
                System.out.println("dateStart is equal to dateEnd ");
                result=true;
            }else{
                System.out.println("How to get here?");
            }

        }catch(ParseException ex){
            ex.printStackTrace();
        }
  return result;

  }