java - 如何在 Java Android Studio 中验证日月和年，

Question

我有这个代码，但是 runValidations 没有检查月份和年份是否真的正确。编译器没有显示任何错误或任何内容。我一遍又一遍地阅读代码，但不知道如何解决此验证问题，非常感谢您的帮助。
我已经尝试了我能想到的所有可能的事情，但我还没有到任何地方。

 {

    ActivityMainBinding binding;
    boolean isPasswordHidden = true;

    public static final String USER_EXTRA = "USER_EXTRA";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        binding = ActivityMainBinding.inflate(getLayoutInflater());
        setContentView(binding.getRoot());
        binding.button.setOnClickListener(this::runValidations);
        binding.ivHidden.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                isPasswordHidden = !isPasswordHidden;
                if (isPasswordHidden) {
                    binding.ivHidden.setImageResource(R.drawable.ic_baseline_visibility_off_24);
                    binding.etPassword.setTransformationMethod(new PasswordTransformationMethod());
                } else {
                    binding.ivHidden.setImageResource(R.drawable.ic_baseline_visibility_24);
                    binding.etPassword.setTransformationMethod(null);
                }
                binding.etPassword.setSelection(binding.etPassword.getText().length());
            }
        });
        binding.cbTerms.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                binding.button.setEnabled(isChecked);
            }
        });
    }


    public void runValidations(View view) {

        boolean isEverythingOk = verifyForEmptyField(binding.etName)
                && verifyForEmptyField(binding.etLastName)
                && verifyForEmptyField(binding.etMail)
                && verifyForEmptyField(binding.etPassword)
                && verifyForEmptyField(binding.etDays)
                && verifyForEmptyField(binding.etMonths)
                && verifyForEmptyField(binding.etYears)
                && validateEmailAddressField()
                && validatePasswordLength()
                && validateDay()
                && validateMonth()
                && validateYear();

        if (isEverythingOk) {
            Intent intent = new Intent(this, SuccessActivity.class);
            User user = new User(
                    getTrimmedText(binding.etName),
                    getTrimmedText(binding.etLastName),
                    getTrimmedText(binding.etMail),
                    getTrimmedText(binding.etPassword),
                    "", ""
            );
            intent.putExtra(USER_EXTRA, user);
            startActivity(intent);
            finish();
        }
    }


    private boolean verifyForEmptyField(EditText editText) {
        String fieldContent = getTrimmedText(editText);
        boolean isValid = !fieldContent.isEmpty();
        if (!isValid) {
            editText.setError(getString(R.string.error_empty_field));
        }
        return isValid;
    }

    private String getTrimmedText(EditText editText) {
        return editText.getText().toString().trim();
    }

    private boolean validateEmailAddressField() {
        boolean isValid = Patterns.EMAIL_ADDRESS.matcher(getTrimmedText(binding.etMail)).matches();
        if (!isValid) {
            binding.etMail.setError(getString(R.string.error_invalid_email));
        }
        return isValid;
    }

    private boolean validatePasswordLength() {
        String password = getTrimmedText(binding.etPassword);
        boolean isValid = password.length() >= 10;
        if (!isValid) {
            binding.etPassword.setError(getString(R.string.error_password_lenght));
        }
        return isValid;
    }

    private int parseETtoInt(EditText editText) {
        try {
            String content =getTrimmedText(editText);
            return Integer.parseInt(content);
        } catch (NumberFormatException e) {
            return -1;
        }
    }

    public boolean validateDay() {
        int valueD= parseETtoInt(binding.etDays);
        boolean isValid = (valueD <= 31 && valueD > 0);
        if (!isValid){
            binding.etDays.setError(getString(R.string.error_invalid_day));
        }
        return isValid;
    }

    public boolean validateMonth() {
        int valueM= parseETtoInt(binding.etMonths);
        boolean isValid = (valueM >=1 && valueM <= 12);
        if (!isValid){
            binding.etMonths.setError(getString(R.string.error_invalid_month));
        }
        return isValid;
    }

    public boolean validateYear() {
        int valueY= parseETtoInt(binding.etYears);
        boolean isValid = (valueY < 2021 && valueY > 1900);
        if (!isValid){
            binding.etYears.setError(getString(R.string.error_invalid_year));
        }
        return isValid;
    }

}

它运行对姓名、姓氏、邮件、密码的验证。除了日期之外的所有内容，运行 avd 我可以在日期上输入任何值，并且当我引入错误值时不会显示错误。

Answer 1

分别验证年、月和日不仅复杂而且容易出错。我建议您验证可以通过组合来自 binding.etYears 的值来形成的完整日期字符串。 , binding.etMonths , 和 binding.etDays .
演示:

import java.time.DateTimeException;
import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
import java.time.format.ResolverStyle;
import java.util.Locale;

class Main {
    // Simulating year, month and day
    static String etYears = "2020";
    static String etMonths = "2";
    static String etDays = "23";

    public static void main(String[] args) {
        // Tests

        System.out.println(isValidDate());

        etDays = "30";
        System.out.println(isValidDate());

        etMonths = "13";
        etDays = "23";
        System.out.println(isValidDate());

        etYears = "1855";
        etMonths = "2";
        System.out.println(isValidDate());
    }

    static boolean isValidDate() {
        DateTimeFormatter dtf = DateTimeFormatter.ofPattern("uuuu-M-d", Locale.ENGLISH)
                                            .withResolverStyle(ResolverStyle.STRICT);

        String strDate = etYears + "-" + etMonths + "-" + etDays;
        System.out.println(strDate);

        try {
            LocalDate date = LocalDate.parse(strDate, dtf);
            int year = date.getYear();
            return year < 2021 && year > 1900;
        } catch (DateTimeException e) {
            return false;
        }
    }
}

输出:

2020-2-23
true
2020-2-30
false
2020-13-23
false
1855-2-23
false

从 了解有关现代日期时间 API 的更多信息Trail: Date Time .
注: java.util日期时间 API 及其格式 API， SimpleDateFormat过时且容易出错。建议完全停止使用它们并切换到 modern date-time API .

无论出于何种原因，如果您必须坚持使用 Java 6 或 Java 7，您可以使用 ThreeTen-Backport将大部分 java.time 功能向后移植到 Java 6 和 7。

如果您正在为 Android 项目工作并且您的 Android API 级别仍然不符合 Java-8，请查看 Java 8+ APIs available through desugaring和 How to use ThreeTenABP in Android Project .