参数的输入和验证问题是开发时经常遇到的,一般的验证方法如下:
public bool Register(string name, int age) { if (string.IsNullOrEmpty(name)) { throw new ArgumentException("name should not be empty", "name"); } if (age < 10 || age > 70) { throw new ArgumentException("the age must between 10 and 70","age"); } //... }
这样做当需求变动的时候,要改动的代码相应的也比较多,这样比较麻烦,最近接触到了Java和C#下2种方便的参数验证方法,简单的介绍下。
Java参数验证:
采用google的guava下的一个辅助类:
import com.google.common.base.Preconditions;
示例代码:
public static void checkPersonInfo(int age, String name){ Preconditions.checkNotNull(name, "name为null"); Preconditions.checkArgument(name.length() > 0, "name的长度要大于0"); Preconditions.checkArgument(age > 0, "age必须大于0"); System.out.println("a person age: " + age + ", name: " + name); } public static void getPostCode(String code){ Preconditions.checkArgument(checkPostCode(code),"邮政编码不符合要求"); System.out.println(code); } public static void main(String[] args) { try { checkPersonInfo(10,"fdsfsd"); checkPersonInfo(10,null); checkPersonInfo(-10,"fdsfsd"); getPostCode("012234"); } catch (Exception e) { e.printStackTrace(); } }
当参数不满足要求的时候,抛出异常信息,异常中携带的信息为后面自定义的字符串,这样写就方便多了。
C#参数验证:
采用FluentValidation这个类库,参考地址在下面。
使用方法:
一个简单的Person类:
public class Person { public string Name { set; get; } public int Age { set; get; } public Person(string name, int age) { Name = name; Age = age; } }
Person的验证类:
public class PersonValidator : AbstractValidator<Person> { public PersonValidator() { RuleFor(x => x.Name).NotEmpty().WithMessage("姓名不能为空"); RuleFor(x => x.Name).Length(1,50).WithMessage("姓名字符不能超过50"); RuleFor(x => x.Age).GreaterThan(0).WithMessage("年龄必须要大于0"); } private bool ValidName(string name) { // custom name validating logic goes here return true; } }
使用:
class Program { static void Main(string[] args) { Person customer = new Person(null,-10); PersonValidator validator = new PersonValidator(); ValidationResult results = validator.Validate(customer); bool validationSucceeded = results.IsValid; IList<ValidationFailure> failures = results.Errors; foreach (var failure in failures) { Console.WriteLine(failure.ErrorMessage); } Console.ReadKey(); } }
FluentValidation的使用文档:http://fluentvalidation.codeplex.com/documentation
以上就是小编为大家带来的Java和C#下的参数验证方法的全部内容了,希望对大家有所帮助,多多支持呐喊教程~