CODEWITHSUNDEEP
javamysqlspring-bootspring-data-jpa
Vignesh R
Vignesh R

Reputation: 211

Spring Data JPA query returns null

My project based on spring boot,Thymeleaf,mysql,html and Jquery.

i wrote a query for checking user name and password is valid or not,if valid means return TRUE otherwise false..This is my scenario..but it passing null...so it becomes nullpointer exception.. Here is my code

public interface RepoUserSignup extends JpaRepository<EntUserSignup, Integer> 
{

    @Query("SELECT pk FROM EntUserSignup pk WHERE pk.username=:uname AND pk.password=:pwd")
    Boolean checkUsername(@Param("uname") String username,@Param("pwd") String password);


}

Please help me..Thanks in advance

Upvotes: 4

Views: 20283

Answers (3)

Cepr0
Cepr0

Reputation: 30279

Replace your method with this:

Optional<EntUserSignup> findByUsernameAndPassword(String username, String password);

Then in your business layer you can do something like this:

EntUserSignup user = findByUsernameAndPassword(username, password)
                     .orElseThrow(() -> new UsernameNotFoundException("User not found!"));

And of cause don't forget about password in plain text...

A good tutorial how to implement security in Spring Boot application...

Upvotes: 3

Vignesh R
Vignesh R

Reputation: 211

i just change my return type

@Query("SELECT pk FROM EntUserSignup pk WHERE pk.username=:uname AND pk.password=:pwd")
    EntUserSignup checkUsername(@Param("uname") String username,@Param("pwd") String password);

So when passing username and password matches menans it will return the entity value otherwise null.so we can decide there is no matched username and password.then we can write the logic as

@Service

public Boolean doCheckUserLogin(EntUserSignup user) {
        Boolean result = false;
        try {
            EntUserSignup entResult = repoSignup.checkUsername(user.getUsername(),user.getPassword());
            if(entResult!=null)
            {
                result = true;
            }
            else
            {
                result = false;
            }
        } catch (Exception e) {
            // TODO: handle exception
            e.printStackTrace();
            result = false;
        }
        return result;
    }

This logics works perfectly...

Upvotes: 1

Youcef LAIDANI
Youcef LAIDANI

Reputation: 59950

Your query return an Object and not a boolean so you have two ways :

  • Your method should return EntUserSignup checkUsername(@Param("uname") String username,@Param("pwd") String password); instead then check if there are a result or not
  • Another way is to check the number of result @Query("SELECT COUNT(pk) > 0 FROM EntUserSignup pk WHERE pk.username=:uname AND pk.password=:pwd") so if there are some results COUNT(pk) > 0 will return true else it will return false

Upvotes: 2

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