[JAVA] Spring validation and error code

Data binding annotation

Annotation used in the domain class.

Annotation	Description	Example
@NumberFormat	Converts a string in the specified format to a numeric type.	＠NumberFormat(pattern="#,###")
＠DateTimeFormat	Converts a string in the specified format to a date type.	@DateTimeFormat(pattern＝"yyyy/MM/dd")

`Form.java`


import org.springframework.format.annotation.DateTimeFormat;

public class SignupForm {

  @DateTimeFormat(pattern="yyyy/MM/dd")
  private Date birthday;
}

Data binding error message

Create messages.properties in the resouces directory and write as follows. There is no need for ** double quotation marks ** after the equal.

pattern	Description method	Description example
１	typeMismatch..=	typeMismatch.signupForm.age=Please enter a number
２	typeMismatch.=	typeMismatch.age=Please enter a number
３	typeMismatch.=	typeMismatch.int=Please enter a number

List of validation annotations

Annotation used in the domain class.

Classification	Annotation	Description
Bean Validation	@NotNull	Check that it is not null
	@NotEmpty	Check that the string or Collection is not null or empty
	@NutBlank	Check that the string is not only null, empty string, whitespace
	@Max	Check if it is less than or equal to the specified value
	@Min	Check if it is more than the specified value
	@Size	Check if the length of the string and the size of the Collection are within the specified range
	@AssertTrue	Check if true
	@AssertFale	Check if false
	@Pattern	Check if it matches the specified regular expression
	@Email	Check if the string is in the form of an email address
Hibernate Validator	@Range	Check if the value is within the specified range
	@Length	Check if the length of the string is within the specified range
	@CreditCardNumber	Check if the string is in credit card number format
	@URL	Check if the string is in URL format

Differences between NotNull NotEmpty Not Blank

An error will occur at ** NG **.

Annotation	null	Empty string	Blank
@NotNull	NG	OK	OK
@NotEmpty	NG	NG	OK
@NotBlank	NG	NG	NG

`Form.java`


//When the classification is Bean Validation
// javax.validation.Import from constraints
import javax.validation.constraints.NotBlank;
import javax.validation.constraints.Email;
import javax.validation.constraints.Pattern;

//Classification is Hibernate Validator
//　org.hibernate.validator.Import from constraints
import org.hibernate.validator.constraints.Length;

public class SignupForm {
  
  //Required input, email address format
  @NotBlank
  @Email
  private String userId;

  @Length(min=4, max=8)
  @Pattern(regexp="^[a-zA-Z0-9]+$")
  private String password;
}

Validation error message

Add to the same messages.properties as the data binding error message

pattern	Description method	Description example
１	..=	NotBlank.signupForm.userId=Please enter your user ID
２	.=	NotBlank.uerId=Please enter your user ID
３	.=	NotBlank.java.lang.Sting ≒ required input
４	=	NotBlank=Required input
５	=	require_check=Required