Parameter validation under Java and C #

The input and validation of parameters is often encountered during development, and the general verification method is as follows:

 Public BOOLRegister (stringNameintAge ) {    if(string. IsNullOrEmpty (name)) {Throw NewArgumentException ("name should not being empty","name"); }    if(Age <Ten|| Age > -)    {        Throw NewArgumentException ("The age must between"," Age"); }    //...}

In doing so when the demand changes, the code to change the corresponding more, this is more troublesome, recently exposed to Java and C # 2 kinds of convenient parameter verification method, simple introduction.

Java Parameter Validation:

Use an auxiliary class under Google's guava:

import com.google.common.base.Preconditions;

Example code:

 Public Static voidCheckpersoninfo (intAge , String name) {preconditions.checknotnull (name,"Name is null"); Preconditions.checkargument (Name.length ()> 0, "name is longer than 0"); Preconditions.checkargument ( Age> 0, "Age must be greater than 0"); System.out.println (' A person Age: ' + age + ', Name: ' +name); }         Public Static voidGetpostcode (String code) {preconditions.checkargument (Checkpostcode (code),"ZIP code does not meet the requirements");    SYSTEM.OUT.PRINTLN (code); }     Public Static voidMain (string[] args) {Try{checkpersoninfo (Ten, "FDSFSD"); Checkpersoninfo (10,NULL); Checkpersoninfo (-10, "FDSFSD"); Getpostcode ("012234"); } Catch(Exception e) {e.printstacktrace (); }    }

When the parameter does not satisfy the request, throws the exception information, the exception carries the information to be later the custom string, this writes is more convenient.

C # Parameter Validation:

Use fluentvalidation this class library, the reference address is below.

How to use:

A simple Person class:

    Publicclass  person    {        publicstringsetget ; }          Public int Set Get ; }          Public Person (stringint age )        {            = name;             = Age ;        }    }

Validation class for Person:

     Public classPersonvalidator:abstractvalidator<person>    {         PublicPersonvalidator () {rulefor (x= X.name). Notempty (). Withmessage ("the name cannot be empty"); Rulefor (x= X.name). Length (1, -). Withmessage ("Last name character cannot exceed"); Rulefor (x= X.age). GreaterThan (0). Withmessage ("age must be greater than 0"); }        Private BOOLValidname (stringname) {            //Custom name validating logic goes here            return true; }    }

Use:

    classProgram {Static voidMain (string[] args) {Person Customer=NewPerson (NULL,-Ten); Personvalidator Validator=NewPersonvalidator (); Validationresult Results=Validator.            Validate (customer); BOOLvalidationsucceeded =results.            IsValid; IList<ValidationFailure> failures =results.            Errors; foreach(varFailureinchfailures) {Console.WriteLine (failure).            ErrorMessage);        } console.readkey (); }    }

Fluentvalidation documentation for use: http://fluentvalidation.codeplex.com/documentation

Resources:

http://fluentvalidation.codeplex.com/

Https://github.com/JeremySkinner/FluentValidation

Parameter validation under Java and C #