Develop Reference

Spring invalid target for Validator

I am trying to validate the string email to check if it already appears within my MYSQL database, when I execute with an email thats already used I get the following error:
java.lang.IllegalStateException: Invalid target for Validator [co2103.hw2.controller.TestResultsValidator#62b41c6]: org.springframework.validation.BeanPropertyBindingResult: 1 errors
Field error in object 'testResults' on field 'email': rejected value [abc#le.ac.uk]; codes [email.testResults.email,email.email,email.java.lang.String,email]; arguments []; default message [is already provided by a different user! Please user another one!]
Here is the validator code
public class TestResultsValidator implements Validator{
private TestResultsRepository TrRepo;
private HomeTestRepository HTRepo;
public TestResultsValidator (TestResultsRepository TrRepo, HomeTestRepository HTRepo) {
this.TrRepo = TrRepo;
this.HTRepo = HTRepo;
}
#Override
public boolean supports(Class<?> clazz) {
return TestResults.class.equals(clazz);
}
#Override
public void validate(Object target, Errors errors) {
TestResults tr = (TestResults) target;
for(TestResults t : TrRepo.findAll()) {
//SAME EMAIL
if (tr.getEmail().equals(t.getEmail())) {
errors.rejectValue("email", "email", "is already provided by a different user! Please user another one!");
System.out.println("Email is already taken by a different user, please try another username");
break;
}
The controller code
//Add new results
#RequestMapping(value = "/addResults",method = {RequestMethod.POST , RequestMethod.GET})
public String newHotel(#Valid #ModelAttribute TestResults results, BindingResult result, Model model) {
if (result.hasErrors()) {
model.addAttribute("errors", result);
return "start";
}
else {
trRepo.save(results);
return "Submitted";
}}

You need to register you validator to spring.
First ad Component Annotation to your validtor.
#Component
public class TestResultsValidator implements Validator{
.....
}
Register it in the controller.
#Controller
class TestResultController {
#Autowired
TestResultsValidator testResultsValidator ;
#InitBinder("testResultsValidator")
protected void initMessageBinder(WebDataBinder binder) {
binder.addValidators(testResultsValidator );
}
}

Java Validating a extended Pojo

I am building project on spring boot and want to add validation that are easy to integrate.
I have Pojo for my project as below:
public class Employee{
#JsonProperty("employeeInfo")
private EmployeeInfo employeeInfo;
}
EmployeeInfo class is as below:
public class EmployeeInfo extends Info {
#JsonProperty("empName")
private String employeeName;
}
Info class is as below:
#JsonIgnoreProperties(ignoreUnknown = true)
public class Info {
#JsonProperty("requestId")
protected String requestId;
}
How to I validate if request Id is not blank with javax.validation
My controller class is as below:
#RequestMapping(value = "/employee/getinfo", method = RequestMethod.GET, consumes = MediaType.APPLICATION_JSON_VALUE, produces = MediaType.APPLICATION_JSON_VALUE)
public ResponseEntity<> getEmployee(#RequestBody Employee employee) {
//need to validate input request here
//for e.g to check if requestId is not blank
}
Request :
{
"employeeInfo": {
"requestId": "",
}
}

Considering you are making use of validation-api:
Please try using below to validate if your String is not null or not containing any whitespace
#NotBlank

In order to validate request parameters in controller methods, you can either use builtin validators or custom one(where you can add any type of validations with custom messages.)
Details on how to use custom validations in spring controller, Check how to validate request parameters with validator like given below:
#Component
public class YourValidator implements Validator {
#Override
public boolean supports(Class<?> clazz) {
return clazz.isAssignableFrom(Employee.class);
}
#Override
public void validate(Object target, Errors errors) {
if (target instanceof Employee) {
Employee req = (Employee) target;
ValidationUtils.rejectIfEmptyOrWhitespace(errors, "employeeInfo.requestId", "YourCustomErrorCode", "yourCustomErrorMessage");
//Or above validation can also be done as
if(req.getEmployeeInfo().getRequestId == null){
errors.rejectValue("employeeInfo.requestId", "YourCustomErrorCode", "YourCustomErrorMessage");
}
}
}
}

How to check argument value formatting before controller method?

In my controller I have a method such as bellow:
public QueryResult<TrsAccount> listExclude(String codeAccount, String searchFilter, String order, int pageNumber,
int pageSize){}
But before executing this method I have to chech if:
Assert.TRUE(codeAccount.matches("^[0-9]{1,20}$"));
Because this is very frequent in my application and it is not only this case, I want a general approach to check the argument format. The way I'm using now is the use of AOP, in which:
#Aspect
public class HijackBeforeMethod {
#Pointcut("within(#org.springframework.stereotype.Controller *)")
public void controllerBean() {
}
#Pointcut("execution(* *(..))")
public void methodPointcut() {
}
#Before(value = "controllerBean() && methodPointcut()", argNames = "joinPoint")
public void before(JoinPoint joinPoint) {
MethodSignature signature = (MethodSignature) joinPoint.getSignature();
Object[] args = joinPoint.getArgs();
String[] paramNames = signature.getParameterNames();
for (int count = 0; count < paramNames.length; count++) {
String tempParam = paramNames[count];
Object tempValue = args[count];
if (tempParam.toLowerCase().equalsIgnoreCase("codeAccount") && Assert.isNotNull(tempValue)
&& Assert.isNotEmpty((String) tempValue)) {
Assert.TRUE(((String) tempValue).matches("^[0-9]{1,20}$"));
}
}
}
}
As you can see, this is very rudimentary and error prone code snippet. Is there any better solutions??

Using AOP in Controllers is not really recommended. A better approach would be to use JSR 303 / JSR 349 Bean Validation, but that would probably require wrapping the string in a value object, which is then annotated accordingly.
If you insist on solving this with AOP, you'll probably need a ControllerAdvice

Just like #Sean Patrick Floyd said, using Bean Validation is more advisable.
Firstly, define a class which extends from org.springframework.validation.Validator like:
#Component
public class CodeAccountValidator implements Validator {
#Override
public boolean supports(Class<?> clazz) {
return String.class.equals(clazz);
}
#Override
public void validate(Object target, Errors errors) {
if (Assert.isNotNull(target) && Assert.isNotEmpty((String) target)) {
Assert.TRUE(((String) target).matches("^[0-9]{1,20}$"));
}
}
}
Then add #Validated annotation to your controller like:
public QueryResult<TrsAccount> listExclude(
#Validated(CodeAccountValidator.class)String codeAccount,
String searchFilter,
String order, int pageNumber,
int pageSize) {
... ...
}

Trying to solve this with AOP is something you shouldn't do. Instead use an object to bind your properties and validate that object.
public class QueryCriteria {
private String codeAccount;
private String searchFilter;
private int pageNumber;
private int pageSize;
private String order;
// Getters / Setters.
}
Then modify your controller method
public QueryResult<TrsAccount> listExclude(#Valid QueryCriteria criteria, BIndingResult result) { ... }
Then either use a Spring Validator which validates what you need .
public QueryCriteriaValidator implements Validator {
private final Pattern ACCOUNT_EXPR = Pattern.compile("^[0-9]{1,20}$");
public boolean supports(Class<?> clazz) {
return QueryCriteria.isAssignable(clazz);
}
public void validate(Object target, Errors errors) {
final QueryCriteria criteria = (QueryCriteria) target;
if (!ACCOUNT_EXPR.matcher(criteria.getCodeAccount()).matches()) {
errors.rejectValue("codeAccount", "invalid.format");
}
}
}
In an #InitBinder in your controller method register this validator
#InitBinder
public void initBinder(WebDataBinder binder) {
binder.setValidator(new QueryCriteriaValidator());
}
When using JSR-303 you don't need this and you could simply annotate the codeAccount field with the #Pattern annotation.
#Pattern(regexp="^[0-9]{1,20}$")
private String codeAccount;
The validation works nicely together with Spring MVC and error reporting using I18N. So instead of trying to hack around it with exceptions work with the framework.
I suggest a read of the validation section and binding section of the Spring Reference guide.

Getting annotation value of generic interface in java

I am trying to get the annotation values. This is my scenario as follows:
This is the annotation I declared.
#Retention(RetentionPolicy.RUNTIME)
public #interface PluginMessage {
String name();
String version();
}
This is the class the uses the annotation for some values
#PluginMessage(name = "RandomName", version = "1")
public class Response{
private Date Time;
}
This is a generic interface which will be used in the next code snippet.
public interface ResponseListener<E> {
void onReceive(E response);
}
I Invoke this by calling the following code:
addListener(new ResponseListener<Response>() {
#Override
public void onReceive(Response response) {
System.out.println();
}
});
This is the implementation of the addListener method:
public <E> void addListener(ResponseListener<E> responseListener) {
Annotation[] annotations = responseListener.getClass().getAnnotations();
}
The annotations are always empty, any idea of what I am doing wrong? I am trying to get the value of them here.

You may get annotations here:
.addListener(new ResponseListener<Response>() {
public void onReceive(Response response) {
final Annotation[] annotations = response.getClass().getAnnotations();
for (Annotation annotation : annotations) {
System.out.println("annotation.toString() = " + annotation.toString());
}
}
});
Your .addListener implementation makes no sense. Instead of getting annotations from ResponseListener(which has no annotations) instance, you have to add listener to listeners pool. Then you have to call listener.onReceive(...) for each listener when you will receive the response. I believe something like that should be implemented there.

How to validate Integer or long in spring mvc

class employee{
...
private long phone;
...
}
I want to validate phone number using spring jsr303 validator, In my Controller I am using #valid. I am successfully validating entered value is number or string by using generic typeMismatch placing in error message property file.
But I want to validate entered number format is correct or not.(#pattern for string only)
How to achieve this one,please suggest me.

Normally phone numbers are String and you can validate by using #Pattern, but if you want to validate any fields you can do like this.
Custom annotation Javax validator
#javax.validation.Constraint(validatedBy = { PhoneNumberConstraintValidator.class })
#Target({ METHOD, FIELD, ANNOTATION_TYPE, CONSTRUCTOR, PARAMETER })
#Retention(RUNTIME)
public #interface ValidPhoneNumber {
}
public class PhoneNumberConstraintValidator implements ConstraintValidator<ValidPhoneNumber, Long> {
#Override
public void initialize(final ValidPhoneNumber constraintAnnotation) {
// nop
}
#Override
public boolean isValid(final Long value, final ConstraintValidatorContext context) {
//your custom validation logic
}
}
class employee{
...
private long phone;
#ValidPhoneNumber
public Long getPhone() { return phone; }
...
}
OR simpler if you have hibernate validator, you can just add this method in your entity class.
#org.hibernate.validator.AssertTrue
public boolean validatePhoneNumber() { }