通过吸气剂访问BigDecimal字段时获取java.lang.NoSuchMethodError

Question

我有一个类User，其中有一个BigDecimal字段，它是私有的，我正试图通过getter访问它。

但是当我尝试访问余额时出现NoSuchMethodError

@Service
public class PaymentProcessor {

    @Autowired
    UserDaoService userDao;

    public void withdrawFunds(String payerId, double amount){
        User payer = userDao.getByUserName(payerId);
        if ( payer.getBalance().doubleValue()   // I get Error here
                < amount){
            throw new RuntimeException("Insufficient Funds");
        }
        else {
            payer.updateBalance(BigDecimal.valueOf(amount * (-1)));
            userDao.saveUser(payer);
        }
    }

}

已添加编辑用户类别

@Entity
@Table(name = "users")
public class User {

    @Id
    private String username;
    private String email;
    private String name;
    private String password;
    private BigDecimal balance;
    private String personalInfo;
    private int rating;
    @ManyToMany(cascade = {
            CascadeType.PERSIST,
            CascadeType.MERGE,
    }, fetch = FetchType.EAGER)
    @JoinTable(name = "user_role",
            joinColumns = @JoinColumn(name = "username"),
            inverseJoinColumns = @JoinColumn(name = "role_id")
    )
    private Set<UserRole> userRoles = new HashSet<>();

    public User() {
        userRoles.add(new UserRole("default"));
        this.rating = 0;
        this.balance = BigDecimal.valueOf(0);
    }

    public void updateBalance(BigDecimal balance) {
        this.balance = this.balance.add(balance);
    }

    public BigDecimal getBalance() {
        return balance;
    }

Answer 1

将您的私有变量更改为：private BigDecimal balance = BigDecimal.ZERO;

发生错误，因为在此行User payer = userDao.getByUserName(payerId);中，您没有从User调用默认构造函数