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Java和C#下的参数验证

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

 

参考资料:

http://fluentvalidation.codeplex.com/

https://github.com/JeremySkinner/FluentValidation

 

Java和C#下的参数验证