JSR303 back-end verification

  • What is JSR303?
  • Import the jar package
  • Validation rules
  • Add annotations to properties
  • Add the @valid annotation

What is JSR303?

JSR 303-Bean Validation provides support for back-end data Validation, which is important because if a one-click F12 modification of the front end code successfully bypassed the front end Validation, illegal data will be stored. Should be front-end + back-end + database check constraints can not be less, fully ensure the safety of data specifications.

Import the jar package

Importing dependencies in POM.xml without understanding Maven canClick here.

<! Hibernate </groupId> <artifactId> Hibernate -validator</artifactId> <version>5.1. 0.Final</version> </dependency> <! -- Tomcat7 if the following version of the EL expression is not compatible, <dependency> <groupId>javax.el</groupId> <artifactId>javax.el </artifactId> <version>3.0. 0</version>
    </dependency>
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Validation rules

Constraint The detailed information
@Null The annotated element must be NULL
@NotNull The annotated element must not be NULL
@AssertTrue The annotated element must be true
@AssertFalse The annotated element must be false
@Min(value) The annotated element must be a number whose value must be greater than or equal to the specified minimum
@Max(value) The annotated element must be a number whose value must be less than or equal to the specified maximum
@DecimalMin(value) The annotated element must be a number whose value must be greater than or equal to the specified minimum
@DecimalMax(value) The annotated element must be a number whose value must be less than or equal to the specified maximum
@Size(max, min) The size of the annotated element must be within the specified range
@Digits (integer, fraction) The annotated element must be a number and its value must be within an acceptable range
@Past The annotated element must be a past date
@Future The annotated element must be a future date
@Pattern(value) The annotated element must conform to the specified regular expression
@Email The annotated element must be an E-mail address
@Length The size of the annotated string must be within the specified range
@NotEmpty The value of the annotated string must be non-empty
@Range The annotated element must be in the appropriate scope

The above is all the verification rules provided by the official website. The @pattern is commonly used and you can customize the rules.

Add annotations to properties

Annotate JavaaBean properties where message sets the error message, optionally leaving the default.

public class User {
	@notnull (message="×: account cannot be empty ")
    private Integer uid;

	@NotNull
	@length (min=6, Max =20,message="×: password Length must be 6-20")
    private String password;
    
    @ the Pattern (regexp = "(^ [a - zA - Z0 - _ - 9] 3 dec} {$) | (^ [\ u2E80 - \ u9FFF] {2, 5})", the message = "x: user called 2-5 3-16 English or Chinese digital combination")
    private String name;

    / / @ the Pattern (regexp = "^ ([a - zA - Z0-9 _ \ \. -] +) @ ([\ \. \ \ da - z -] +) \ \. ([a-z \ \] {2, 6}) $"
    //,message="×: mailbox format error ")
    @Email
    private String email;
	
	@Past
	private Date birthday;
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Add the @valid annotation

Add the @VALID annotation to the Controller method argument, and the error message will be placed in the object argument of BindingResult.

	@PostMapping("/user")
	@ResponseBody
	public Msg saveUser(@Valid User user,BindingResult result){
		if (result.hasErrors()){
	            Map<String,Object> map = new HashMap<>();
	            // Verification failed, should return failure, in the modal box display verification failed error message
	            List<FieldError> errors = result.getFieldErrors();
	            for (FieldError fieldError:errors){
	                System.out.println("Error field name:"+fieldError.getField());
	                System.out.println(Error message:+fieldError.getDefaultMessage());
	                map.put(fieldError.getField(),fieldError.getDefaultMessage());
	            }
	            return Msg.fail().add("errorFields",map);
	        }else {
	        	userService.saveUser(user);
	    		returnMsg.success(); }}Copy the code

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