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Java 使用推土机进行集合映射时的无限循环

java collections mapping

Java 使用推土机进行集合映射时的无限循环,java,collections,mapping,infinite-loop,dozer,Java,Collections,Mapping,Infinite Loop,Dozer,我正在开发一个项目，它在前端使用BackboneJS，在后端使用Java-Spring内核。我在将实体（域）对象映射到DTO对象时遇到问题。我收到这样的错误消息： org.apache.cxf.interceptor.Fault:无限递归（StackOverflowerError）（通过引用链：com.countdown.dto.CategoryDTO[“countdownList”]->java.util.ArrayList[0]->com.countdown.dto.CountdownDTO

我正在开发一个项目，它在前端使用BackboneJS，在后端使用Java-Spring内核。我在将实体（域）对象映射到DTO对象时遇到问题。我收到这样的错误消息：

org.apache.cxf.interceptor.Fault:无限递归（StackOverflowerError）（通过引用链：com.countdown.dto.CategoryDTO[“countdownList”]->java.util.ArrayList[0]->com.countdown.dto.CountdownDTO[“category”]->

User.java

@Entity
@Table(name = "Users")
public class User implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "USER_ID", nullable = false)
    private int id;

    @Column(name = "EMAIL", nullable = false, unique = true)
    private String email;

    @Column(name = "NAME_SURNAME", nullable = false)
    private String nameSurname;

    @Column(name = "PASSWORD", nullable = false)
    private String password;

    @Column(name = "USERNAME", nullable = false, unique = true)
    private String username;

    @Column(name = "REGISTER_DATE", nullable = false)
    private Date registerDate;

    @ManyToOne
    @JoinColumn(name = "ROLE_ID")
    private Role role;

    @OneToMany(mappedBy = "createUser")
    private List<Countdown> createCountdownList = new ArrayList<Countdown>();

    @OneToMany(mappedBy = "updateUser")
    private List<Countdown> updateCountdownList = new ArrayList<Countdown>();

    @ManyToMany
    @JoinTable(name = "FOLLOWINGS",
            joinColumns = @JoinColumn(name = "USER_ID"),
            inverseJoinColumns = @JoinColumn(name = "COUNTDOWN_ID"))
    private List<Countdown> followings = new ArrayList<Countdown>();

    //Getters and setters..

}

@Entity
public class Role implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "ROLE_ID")
    private int id;

    @Column(name = "ROLE_NAME", nullable = false)
    private String roleName;

    @OneToMany(mappedBy = "role",fetch = FetchType.LAZY)
    List<User> userList = new ArrayList<User>();
 }

@Entity
@Table(name = "COUNTDOWN")
public class Countdown implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "COUNTDOWN_ID")
    private int id;

    @Column(name = "COUNTDOWN_NAME", nullable = false)
    private String countdownName;

    @Column(name = "COUNTDOWN_DATE", nullable = false)
    private Date countdownDate;

    @Column(columnDefinition = "varchar(5000)")
    private String countdownDescription;

    @JoinColumn(name = "CATEGORY_ID", nullable = false)
    @ManyToOne
    private Category category;

    @JoinColumn(name = "CREATE_USER", nullable = false)
    @ManyToOne
    private User createUser;

    @Column(name = "CREATE_DATE", nullable = false)
    private Date createDate;

    @JoinColumn(name = "UPDATE_USER", nullable = false)
    @ManyToOne
    private User updateUser;

    @Column(name = "UPDATE_DATE", nullable = false)
    private Date updateDate;

    @Column(name = "CREATE_USER_IP", nullable = false)
    private int createIP;

    @ManyToMany
    private List<User> followers = new ArrayList<User>();

}

@Entity
@Table(name="CATEGORY")
public class Category implements Serializable{

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name="CATEGORY_ID")
    private int id;

    @Column(name = "CATEGORY_NAME" , nullable = false)
    private String categoryName;

    @OneToMany(mappedBy = "category")
    private List<Countdown> countdownList = new ArrayList<Countdown>();

}

@实体
@表（name=“Users”）
公共类用户实现可序列化{
@身份证
@GeneratedValue（策略=GenerationType.AUTO）
@列（name=“USER\u ID”，null=false）
私有int-id；
@列（name=“EMAIL”，nullable=false，unique=true）
私人字符串电子邮件；
@列（name=“name\u姓氏”，null=false）
私有字符串名称；
@列（name=“PASSWORD”，null=false）
私有字符串密码；
@列（name=“USERNAME”，nullable=false，unique=true）
私有字符串用户名；
@列（name=“REGISTER\u DATE”，null=false）
私人日期登记日期；
@许多酮
@JoinColumn（name=“ROLE\u ID”）
私人角色；
@OneToMany（mappedBy=“createUser”）
私有列表createCountdownList=新的ArrayList（）；
@OneToMany（mappedBy=“updateUser”）
私有列表updateCountdownList=新的ArrayList（）；
@许多
@JoinTable（name=“followers”，
joinColumns=@JoinColumn（name=“USER\u ID”），
inverseJoinColumns=@JoinColumn（name=“COUNTDOWN\u ID”））
以下私有列表=新的ArrayList（）；
//能手和二传手。。
}
Role.java

@Entity
@Table(name = "Users")
public class User implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "USER_ID", nullable = false)
    private int id;

    @Column(name = "EMAIL", nullable = false, unique = true)
    private String email;

    @Column(name = "NAME_SURNAME", nullable = false)
    private String nameSurname;

    @Column(name = "PASSWORD", nullable = false)
    private String password;

    @Column(name = "USERNAME", nullable = false, unique = true)
    private String username;

    @Column(name = "REGISTER_DATE", nullable = false)
    private Date registerDate;

    @ManyToOne
    @JoinColumn(name = "ROLE_ID")
    private Role role;

    @OneToMany(mappedBy = "createUser")
    private List<Countdown> createCountdownList = new ArrayList<Countdown>();

    @OneToMany(mappedBy = "updateUser")
    private List<Countdown> updateCountdownList = new ArrayList<Countdown>();

    @ManyToMany
    @JoinTable(name = "FOLLOWINGS",
            joinColumns = @JoinColumn(name = "USER_ID"),
            inverseJoinColumns = @JoinColumn(name = "COUNTDOWN_ID"))
    private List<Countdown> followings = new ArrayList<Countdown>();

    //Getters and setters..

}

@Entity
public class Role implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "ROLE_ID")
    private int id;

    @Column(name = "ROLE_NAME", nullable = false)
    private String roleName;

    @OneToMany(mappedBy = "role",fetch = FetchType.LAZY)
    List<User> userList = new ArrayList<User>();
 }

@Entity
@Table(name = "COUNTDOWN")
public class Countdown implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "COUNTDOWN_ID")
    private int id;

    @Column(name = "COUNTDOWN_NAME", nullable = false)
    private String countdownName;

    @Column(name = "COUNTDOWN_DATE", nullable = false)
    private Date countdownDate;

    @Column(columnDefinition = "varchar(5000)")
    private String countdownDescription;

    @JoinColumn(name = "CATEGORY_ID", nullable = false)
    @ManyToOne
    private Category category;

    @JoinColumn(name = "CREATE_USER", nullable = false)
    @ManyToOne
    private User createUser;

    @Column(name = "CREATE_DATE", nullable = false)
    private Date createDate;

    @JoinColumn(name = "UPDATE_USER", nullable = false)
    @ManyToOne
    private User updateUser;

    @Column(name = "UPDATE_DATE", nullable = false)
    private Date updateDate;

    @Column(name = "CREATE_USER_IP", nullable = false)
    private int createIP;

    @ManyToMany
    private List<User> followers = new ArrayList<User>();

}

@Entity
@Table(name="CATEGORY")
public class Category implements Serializable{

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name="CATEGORY_ID")
    private int id;

    @Column(name = "CATEGORY_NAME" , nullable = false)
    private String categoryName;

    @OneToMany(mappedBy = "category")
    private List<Countdown> countdownList = new ArrayList<Countdown>();

}

@实体
公共类角色实现可序列化{
@身份证
@GeneratedValue（策略=GenerationType.AUTO）
@列（name=“ROLE\u ID”）
私有int-id；
@列（name=“ROLE\u name”，nullable=false）
私有字符串roleName；
@OneToMany（mappedBy=“role”，fetch=FetchType.LAZY）
List userList=new ArrayList（）；
}
Countdown.java

@Entity
@Table(name = "Users")
public class User implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "USER_ID", nullable = false)
    private int id;

    @Column(name = "EMAIL", nullable = false, unique = true)
    private String email;

    @Column(name = "NAME_SURNAME", nullable = false)
    private String nameSurname;

    @Column(name = "PASSWORD", nullable = false)
    private String password;

    @Column(name = "USERNAME", nullable = false, unique = true)
    private String username;

    @Column(name = "REGISTER_DATE", nullable = false)
    private Date registerDate;

    @ManyToOne
    @JoinColumn(name = "ROLE_ID")
    private Role role;

    @OneToMany(mappedBy = "createUser")
    private List<Countdown> createCountdownList = new ArrayList<Countdown>();

    @OneToMany(mappedBy = "updateUser")
    private List<Countdown> updateCountdownList = new ArrayList<Countdown>();

    @ManyToMany
    @JoinTable(name = "FOLLOWINGS",
            joinColumns = @JoinColumn(name = "USER_ID"),
            inverseJoinColumns = @JoinColumn(name = "COUNTDOWN_ID"))
    private List<Countdown> followings = new ArrayList<Countdown>();

    //Getters and setters..

}

@Entity
public class Role implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "ROLE_ID")
    private int id;

    @Column(name = "ROLE_NAME", nullable = false)
    private String roleName;

    @OneToMany(mappedBy = "role",fetch = FetchType.LAZY)
    List<User> userList = new ArrayList<User>();
 }

@Entity
@Table(name = "COUNTDOWN")
public class Countdown implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "COUNTDOWN_ID")
    private int id;

    @Column(name = "COUNTDOWN_NAME", nullable = false)
    private String countdownName;

    @Column(name = "COUNTDOWN_DATE", nullable = false)
    private Date countdownDate;

    @Column(columnDefinition = "varchar(5000)")
    private String countdownDescription;

    @JoinColumn(name = "CATEGORY_ID", nullable = false)
    @ManyToOne
    private Category category;

    @JoinColumn(name = "CREATE_USER", nullable = false)
    @ManyToOne
    private User createUser;

    @Column(name = "CREATE_DATE", nullable = false)
    private Date createDate;

    @JoinColumn(name = "UPDATE_USER", nullable = false)
    @ManyToOne
    private User updateUser;

    @Column(name = "UPDATE_DATE", nullable = false)
    private Date updateDate;

    @Column(name = "CREATE_USER_IP", nullable = false)
    private int createIP;

    @ManyToMany
    private List<User> followers = new ArrayList<User>();

}

@Entity
@Table(name="CATEGORY")
public class Category implements Serializable{

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name="CATEGORY_ID")
    private int id;

    @Column(name = "CATEGORY_NAME" , nullable = false)
    private String categoryName;

    @OneToMany(mappedBy = "category")
    private List<Countdown> countdownList = new ArrayList<Countdown>();

}

@实体
@表（name=“倒计时”）
公共类倒计时实现可序列化{
@身份证
@GeneratedValue（策略=GenerationType.AUTO）
@列（name=“倒计时\u ID”）
私有int-id；
@列（name=“COUNTDOWN\u name”，null=false）
私有字符串倒计时名称；
@列（name=“COUNTDOWN\u DATE”，null=false）
私人日期倒计时；
@列（columnDefinition=“varchar（5000）”）
私有字符串倒计时描述；
@JoinColumn（name=“CATEGORY\u ID”，nullable=false）
@许多酮
私人类别；
@JoinColumn（name=“CREATE\u USER”，nullable=false）
@许多酮
私有用户；
@列（name=“CREATE_DATE”，null=false）
私人日期；
@JoinColumn（name=“UPDATE\u USER”，nullable=false）
@许多酮
私有用户更新器；
@列（name=“UPDATE\u DATE”，null=false）
私人日期更新日期；
@列（name=“CREATE\u USER\u IP”，null=false）
私有IP；
@许多
private List followers=new ArrayList（）；
}
Category.java

@Entity
@Table(name = "Users")
public class User implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "USER_ID", nullable = false)
    private int id;

    @Column(name = "EMAIL", nullable = false, unique = true)
    private String email;

    @Column(name = "NAME_SURNAME", nullable = false)
    private String nameSurname;

    @Column(name = "PASSWORD", nullable = false)
    private String password;

    @Column(name = "USERNAME", nullable = false, unique = true)
    private String username;

    @Column(name = "REGISTER_DATE", nullable = false)
    private Date registerDate;

    @ManyToOne
    @JoinColumn(name = "ROLE_ID")
    private Role role;

    @OneToMany(mappedBy = "createUser")
    private List<Countdown> createCountdownList = new ArrayList<Countdown>();

    @OneToMany(mappedBy = "updateUser")
    private List<Countdown> updateCountdownList = new ArrayList<Countdown>();

    @ManyToMany
    @JoinTable(name = "FOLLOWINGS",
            joinColumns = @JoinColumn(name = "USER_ID"),
            inverseJoinColumns = @JoinColumn(name = "COUNTDOWN_ID"))
    private List<Countdown> followings = new ArrayList<Countdown>();

    //Getters and setters..

}

@Entity
public class Role implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "ROLE_ID")
    private int id;

    @Column(name = "ROLE_NAME", nullable = false)
    private String roleName;

    @OneToMany(mappedBy = "role",fetch = FetchType.LAZY)
    List<User> userList = new ArrayList<User>();
 }

@Entity
@Table(name = "COUNTDOWN")
public class Countdown implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "COUNTDOWN_ID")
    private int id;

    @Column(name = "COUNTDOWN_NAME", nullable = false)
    private String countdownName;

    @Column(name = "COUNTDOWN_DATE", nullable = false)
    private Date countdownDate;

    @Column(columnDefinition = "varchar(5000)")
    private String countdownDescription;

    @JoinColumn(name = "CATEGORY_ID", nullable = false)
    @ManyToOne
    private Category category;

    @JoinColumn(name = "CREATE_USER", nullable = false)
    @ManyToOne
    private User createUser;

    @Column(name = "CREATE_DATE", nullable = false)
    private Date createDate;

    @JoinColumn(name = "UPDATE_USER", nullable = false)
    @ManyToOne
    private User updateUser;

    @Column(name = "UPDATE_DATE", nullable = false)
    private Date updateDate;

    @Column(name = "CREATE_USER_IP", nullable = false)
    private int createIP;

    @ManyToMany
    private List<User> followers = new ArrayList<User>();

}

@Entity
@Table(name="CATEGORY")
public class Category implements Serializable{

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name="CATEGORY_ID")
    private int id;

    @Column(name = "CATEGORY_NAME" , nullable = false)
    private String categoryName;

    @OneToMany(mappedBy = "category")
    private List<Countdown> countdownList = new ArrayList<Countdown>();

}

@实体
@表（name=“CATEGORY”）
公共类类别实现可序列化{
@身份证
@GeneratedValue（策略=GenerationType.AUTO）
@列（name=“CATEGORY\u ID”）
私有int-id；
@列（name=“CATEGORY\u name”，nullable=false）
私有字符串categoryName；
@OneToMany（mappedBy=“类别”）
private List countdownList=new ArrayList（）；
}
业务逻辑：CategoryServiceImpl.java 我在forEach循环中遇到错误

@Transactional(readOnly = true)
public List<CategoryDTO> getAllCategories() {
    List<Category> categoryList;
    List<CategoryDTO> categoryDTOList = new ArrayList<CategoryDTO>();

    logger.debug("getAllCategories called");

    try {
        categoryList = categoryDAO.findAll();
        for(Category category : categoryList){
            categoryDTOList.add(mapper.map(category,CategoryDTO.class));
        }
    }catch (NoResultException e){
        logger.error("getAllCategories method : No Category wasn't found");
        logger.warn(e,e);
    }catch (Exception e){
        logger.error("getAllCategories method : Categories wasn't found");
        logger.warn(e,e);
    }
    return categoryDTOList;
}

@Transactional（readOnly=true）
公共列表getAllCategories（）{
列表分类列表；
List CategoryToList=新建ArrayList（）；
debug（“调用getAllCategories”）；
试一试{
categoryList=categoryDAO.findAll（）；
用于（类别：类别列表）{
添加（mapper.map（category，CategoryDTO.class））；
}
}捕获（noresulte异常）{
错误（“getAllCategories方法：未找到任何类别”）；
记录器警告（e，e）；
}捕获（例外e）{
错误（“getAllCategories方法：未找到类别”）；
记录器警告（e，e）；
}
返回分类列表；
}
我还必须在表示层中使用DTO对象吗？我可以在表示层中使用实体对象而不是DTO对象吗

我如何解决这个问题？对不起，我的英语不好。谢谢！

请尝试：

    @Transactional(readOnly = true)
    public List<CategoryDTO> getAllCategories() {
        List<Category> categoryList;
        List<CategoryDTO> categoryDTOList = new ArrayList<CategoryDTO>();

        logger.debug("getAllCategories called");

        try {
            categoryList = categoryDAO.findAll();

            for(Category category : categoryList){
                  if(category.getCountdownList() != null && !category.getCountdownList().isEmpty()){
                      for(Countdown countdown : category.getCountdownList()){
                          countdown.setCategory(null);
                      }
                   }
                categoryDTOList.add(mapper.map(category,CategoryDTO.class));
            }
        }catch (NoResultException e){
            logger.error("getAllCategories method : Hata: No Category wasn't found");
            logger.warn(e,e);
        }catch (Exception e){
            logger.error("getAllCategories method : Hata: Categories wasn't found");
            logger.warn(e,e);
        }
        return categoryDTOList;
    }

@Transactional（readOnly=true）
公共列表getAllCategories（）{
列表分类列表；
List CategoryToList=新建ArrayList（）；
debug（“调用getAllCategories”）；
试一试{
categoryList=categoryDAO.findAll（）；
用于（类别：类别列表）{
if（category.getCountdownList（）！=null&&！category.getCountdownList（）.isEmpty（））{
for（倒计时：category.getCountdownList（））{
倒计时。设置类别（空）；
}
}
添加（mapper.map（category，CategoryDTO.class））；
}
}捕获（noresulte异常）{
错误（“getAllCategories方法：Hata:未找到任何类别”）；
记录器警告（e，e）；
}捕获（例外e）{
错误（“getAllCategories方法：Hata:未找到类别”）；
记录器警告（e，e）；
}
返回分类列表；
}
适用于那些在推土机中挣扎于无限递归问题的人

我使用
mapId
定义一个叶对象并停止递归

假设我们有两个实体
课程
和
教师
，它们包含一个多对多关系，我们希望将