Spring @Valid @Validated实现验证

public class Book {

  @NotBlank(message = "bookID is mandatory, can not be blank")
  public String bookID;
  
  @Size(min=5, max=20)
  @NotBlank(message = "bookName is mandatory, can not be blank")
  public String bookName;
  public String author;
  
  @Valid
  public List<ChapterInfo> chapterList;
  
  public Book(String id, String name, String auth) {
    bookName = name;
    author = auth;
    bookID = id;
  }
}

public class ChapterInfo {
  @Min(0)
  public Long chapterID;
  
  @NotBlank
  @Size(min=5, max=50)
  public String chapterName;
  
  @Size(min=5, max=20)
  public String contentID;
}

@RestController
@RequestMapping("/bookcontroller")
public class BookController {

  private List<Book> bookList = new ArrayList();
  
  @ResponseBody
  @RequestMapping("/addBookToList")
  public boolean addBookToList(@Valid @RequestBody Book b) {
    System.out.println(b.bookName);
    
    bookList.add(b);
    
    return true;
  }
  
  @InitBinder
  private void activateDirectFieldAccess(DataBinder dataBinder) {
    dataBinder.initDirectFieldAccess();
  }
  
}

public class User {
  
  @NotBlank
  public String name;
  
  @NotBlank
  public String address;
  
  @Min(1)
  public int age;

  public boolean isMan;
  
  @NotBlank(groups = {Update.class})
  @Null(groups = {Add.class})
  public String usrID;
  
  public interface Add{}
  
  public interface Update{}
  
  
  public User(String name, String addr, int age, boolean isMan) {
    this.name = name;
    this.address = addr;
    this.age = age;
    this.isMan = isMan;
  }

}

@RestController
@RequestMapping("/registcontroller")
public class RegistController {

  List<User> usrList = new ArrayList();
  
  
  @PostMapping(path="/adduser")
  @ResponseBody
  public User addUser(@RequestBody @Validated({User.Add.class}) User usr, BindingResult result) {
    
    if (result.hasErrors()) {
      List<ObjectError> list = result.getAllErrors();
      FieldError error = (FieldError)list.get(0);
      System.out.println(error.getObjectName() + "," + error.getField() + "," + error.getDefaultMessage());
      return null;
    }
    User user = new User(usr.name, usr.address, usr.age, usr.isMan);
    String usrID = usrList.size() + "";
    
    user.usrID = usrID;
    
    return user;
  }
}