Question

dto object：

public class DTOUser implements UserDetails {
/**
 * 
 */
private static final long serialVersionUID = -769714837633005963L;
private Long id;
private String account;
private String password;
private String statusStr;
private UserStatus status;
private int systemAdmin;
private long operator;
private String operateTime;
private String name;
private String company;
private String email;
private String telephone;
private List<DTOAuthority> dtoAuthorities = new ArrayList<DTOAuthority>();
private List<DTOAgreement> dtoAgreements = new ArrayList<DTOAgreement>();}

实体：

@Entity
@Table(name="adt_user")
public class User {
private long id;
private String account;
private String password;
private String statusStr;
private UserStatus status;
private int systemAdmin;
private long operator;
private String operateTime;
private String name;
private String company;
private String email;
private String telephone;
private Set<Authority> authorities = new HashSet<Authority>();
private Set<Agreement> agreements = new HashSet<Agreement>();}

我使用bellow方法将值复制到实体，但有一个例外：

java.lang.IllegalArgumentException: Cannot invoke com.hna.adt.orm.User.setAuthorities - argument type mismatch

它出了什么问题？

BeanUtils.copyProperties(entity, value);

Answer 1

如果检查权限和协议的类型，则它们与其他类定义不匹配。为了使beanutils正常工作，请确保属性类型匹配。

Answer 2

你有

private List<DTOAuthority> dtoAuthorities = new ArrayList<DTOAuthority>();

VS

private Set<Authority> authorities = new HashSet<Authority>();

如果BeanUtils.copyProperties只考虑元素的setter和getter，并且不够智能，无法确定Set和List都是集合并迭代并逐个复制元素 - 仍然要求Authority与DTOAuthority兼容 - 然后它会抛出此反射错误，然后Set无法从List分配，即不兼容。

如果您尝试在编译时执行相同的操作

entity.setAuthorities(value.getDtoAuthorities());

然后你会得到与编译错误相同的语句。

您应该将dtoAuthorities更改为Set或将authorities更改为List。

参数类型不匹配使用BeanUtils.copyProperties

2 个答案: