Basic Put (Update) on Spring Boot

Question

I want something very basic.

I just want to update the User. Front end sends a json for the user. I wanted to avoid set every value of currentUser (it has like 50 fields)

@PutMapping("user/{id}")
public boolean updateUser(@PathVariable id, @RequestBody User user) {
   User currentUser = userRepo.findOne(id);
   // What now??

}

Answer 1

you need to do something like that. Please keep in mind that this approach is helpful for partial object update. That means if your object(in RequestBody) doesn't contains some fields(field==null) then this field will remain unchanged.

@PutMapping("user/{id}")
public boolean updateUser(@PathVariable id, @RequestBody User user) {
   User currentUser = userRepo.findOne(id);
   user = (User) PersistenceUtils.partialUpdate(currentUser, user);
   return userRepo.save(user);

}

public class PersistenceUtils {

    public static Object partialUpdate(Object dbObject, Object partialUpdateObject){
        String[] ignoredProperties = getNullPropertyNames(partialUpdateObject);
        BeanUtils.copyProperties(partialUpdateObject, dbObject, ignoredProperties);
        return dbObject;
    }

    private static String[] getNullPropertyNames(Object object) {
        final BeanWrapper wrappedSource = new BeanWrapperImpl(object);
        return Stream.of(wrappedSource.getPropertyDescriptors())
                .map(FeatureDescriptor::getName)
                .filter(propertyName -> wrappedSource.getPropertyValue(propertyName) == null)
                .toArray(String[]::new);
    }


}

Answer 2

First Approach:

• If User type it sent from the front-end you don't need to set everything again, you can use the object itself to update the values.

So, you can take these steps:

1. remove {id} from url mapping as id already included in User class
2. check if id has a value, otherwise throw an execption that updating not possible
3. if id is available just execute userRepository.save(user) for updating

4. return body back to front

   @PutMapping("/user")
   public ResponseEntity < User > updateUser(@RequestBody User user) throws 
   URISyntaxException {
       log.debug("REST request to update User : {}", user);
       if (user.getId() == null) {
           throw new ResourceNotFoundException("User id should not be null ")
       }
       User result = userRepository.save(user);
       return ResponseEntity.ok().body(result);
   }
   

And here is the custom Exception definition when id is null:

@ResponseStatus(HttpStatus.NOT_FOUND)
public class ResourceNotFoundException extends RuntimeException {
    public ResourceNotFoundException(String message) {
        super(message);
    }

    public ResourceNotFoundException(String message, Throwable cause) {
        super(message, cause);
    }
}

---

Second Approach:

• If you are still insisting to set huge amount of properties you can use org.springframework.beans.BeanUtils copyProperties as BeanUtils.copyProperties(sourceItem, targetItem)

@PutMapping("/{id}")
public ResponseEntity<User> update(@PathVariable("id") id,  @RequestBody User user) {
    User currentUser = userRepo.findOne(id);
    BeanUtils.copyProperties(user, currentUser);
    return ResponseEntity.ok(repo.save(targetItem));
}