日期验证不起作用

Question

在我的 android 应用程序中有 2 个编辑文本字段，它们取自日期和最后一个日期，我正在尝试检查日期是否有效我尝试使用此代码但它不起作用.. 错误在哪里我找不到请帮我更正代码

String fromdate,todate;
    private Matcher matcher;
    private static final String DATE_PATTERN =
            "(0?[1-9]|1[012]) [/.-] (0?[1-9]|[12][0-9]|3[01]) [/.-] ((19|20)\\d\\d)";

搜索按钮 Onclick 代码

advsearch.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                fromdate=fromed.getText().toString();
                todate=toed.getText().toString();

                matcher = Pattern.compile(DATE_PATTERN).matcher(fromdate);
                matcher = Pattern.compile(DATE_PATTERN).matcher(todate);


      if (!matcher.matches()) {
                    Toast.makeText(getApplicationContext(), "Invalid Date!", Toast.LENGTH_LONG).show();
                }
            }
        });

    }

布尔类

 public boolean validate(String date){

        matcher = pattern.matcher(date);

        if(matcher.matches()){

            matcher.reset();

            if(matcher.find()){

                String day = matcher.group(1);
                String month = matcher.group(2);
                int year = Integer.parseInt(matcher.group(3));

                if (day.equals("31") &&
                        (month.equals("4") || month .equals("6") || month.equals("9") ||
                                month.equals("11") || month.equals("04") || month .equals("06") ||
                                month.equals("09"))) {
                    return false; // only 1,3,5,7,8,10,12 has 31 days
                } else if (month.equals("2") || month.equals("02")) {
                    //leap year
                    if(year % 4==0){
                        if(day.equals("30") || day.equals("31")){
                            return false;
                        }else{
                            return true;
                        }
                    }else{
                        if(day.equals("29")||day.equals("30")||day.equals("31")){
                            return false;
                        }else{
                            return true;
                        }
                    }
                }else{
                    return true;
                }
            }else{
                return false;
            }
        }else{
            return false;
        }
    }
}
}

Answer 1

为数据验证创建单独的类，如下所示..

public class DateValidator {

private Pattern pattern;
private Matcher matcher;

private static final String DATE_PATTERN =
        "(0?[1-9]|[12][0-9]|3[01])/(0?[1-9]|1[012])/((19|20)\\d\\d)";

public DateValidator() {
    pattern = Pattern.compile(DATE_PATTERN);
}

/**
 * Validate date format with regular expression
 *
 * @param date date address for validation
 * @return true valid date fromat, false invalid date format
 */
public boolean validate(final String date) {

    matcher = pattern.matcher(date);

    if (matcher.matches()) {

        matcher.reset();

        if (matcher.find()) {

            String day = matcher.group(1);
            String month = matcher.group(2);
            int year = Integer.parseInt(matcher.group(3));

            if (day.equals("31") &&
                    (month.equals("4") || month.equals("6") || month.equals("9") ||
                            month.equals("11") || month.equals("04") || month.equals("06") ||
                            month.equals("09"))) {
                return false; // only 1,3,5,7,8,10,12 has 31 days
            } else if (month.equals("2") || month.equals("02")) {
                //leap year
                if (year % 4 == 0) {
                    if (day.equals("30") || day.equals("31")) {
                        return false;
                    } else {
                        return true;
                    }
                } else {
                    if (day.equals("29") || day.equals("30") || day.equals("31")) {
                        return false;
                    } else {
                        return true;
                    }
                }
            } else {
                return true;
            }
        } else {
            return false;
        }
    } else {
        return false;
    }
}

}

然后点击按钮后把它放在下面的代码..

 fromdate = et.getText().toString();
            todate = et2.getText().toString();
            DateValidator dateValidator=new DateValidator();
            if (dateValidator.validate(fromdate)){
                Toast.makeText(getApplicationContext(),"Valid",Toast.LENGTH_SHORT).show();
            }
            else{
                Toast.makeText(getApplicationContext(),"InValid",Toast.LENGTH_SHORT).show();

            }

和edittext输入数据格式如dd/mm/yyyy。

有关格式的更多信息，请参阅此链接 http://www.mkyong.com/regular-expressions/how-to-validate-date-with-regular-expression/