How to chain checks in java

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难免孤独 2021-01-06 08:11

Consider a class like the following

public class MyClass {

    private Integer myField;
    private Result result;
    // more global variables

    public


      
      
        
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                   盖世英雄少女心
                                             
                
                
                (楼主)
            
              
              
                2021-01-06 08:41
              

            
            
                        
You could use Hibernate Validator (or another implementation of the JSR 303/349/380 Bean Validation standards).

Example user class that throws an exception when being instantiated with invalid arguments. You can check all the built in constraints in the docs

    public final class User {

      @NotNull
      private final String username;

      @NotNull
      private final String firstName;

      @NotNull
      private final String lastName;

      public User(String username, String firstName, String lastName) {
        this.username = username;
        this.firstName = firstName;
        this.lastName = lastName;

        MyValidator.validate(this);
      }
      // public getters omitted
    }


And the validator class:

import java.security.InvalidParameterException;
import java.util.Set;

import javax.validation.ConstraintViolation;
import javax.validation.Validation;
import javax.validation.Validator;
import javax.validation.ValidatorFactory;

public final class MyValidator {

    public static void validate(Object object) {

      ValidatorFactory factory = Validation.buildDefaultValidatorFactory();
      Validator validator = factory.getValidator();

      Set> constraintViolations = validator.validate( object );

      if (!constraintViolations.isEmpty()) {
          ConstraintViolation