Java 通过父实体更新删除添加子实体列表
是否有更好的方法根据新传递的子实体列表添加、更新、删除子实体(列表) 我的更新功能Java 通过父实体更新删除添加子实体列表,java,spring-data-jpa,hibernate-mapping,Java,Spring Data Jpa,Hibernate Mapping,是否有更好的方法根据新传递的子实体列表添加、更新、删除子实体(列表) 我的更新功能 Parent parent = findById(id); //make changes to parent attributes //parent.setXyz(dto.getXyz()); //convert newly passed sons to hashmap Map<String, Son> newSons = toHashMap(dto.getSons()); List<So
Parent parent = findById(id);
//make changes to parent attributes
//parent.setXyz(dto.getXyz());
//convert newly passed sons to hashmap
Map<String, Son> newSons = toHashMap(dto.getSons());
List<Son> finalSons = new ArrayList<>();
for (Son oldSon : parent.getSons()) {
if (newSons.containsKey(oldSon.getUniqueString())) {
finalSons.add(oldSon);
newSons.remove(oldSon.getUniqueString());
} else {
//Delete the son thats not in new list
sonRepository.delete(oldSon);
}
}
//add remaining sons
for (Son son : newSons) {
finalSons.add(son);
}
//existing.getSons().clear();
//existing.getSons().addAll(finalSons);
existing.getSons().clear();
parentRepository.save(parent);
当你使用JPA的
孤儿删除
功能时,你可以让你的更新过程更轻松一些,但是要小心,因为这会导致你不自觉地删除东西:
Parent.java
@Entity(name=“parents”)
公共类父类{
@身份证
@GeneratedValue(策略=GenerationType.IDENTITY)
私有整数id;
私有字符串标题;
@OneToMany(mappedBy=“parent”,cascade=CascadeType.ALL,fetch=FetchType.EAGER,orphan=true)
私人名单;
}
服务
Parent=findById(id);
Map addedSons=toHashMap(dto.getSons());
//删除不属于更新的现有子系统
parent.getSons().removeIf(existingSon->!addedSons.containsKey(existingSon.getUniqueString());
//增加新儿子
addedSons.forEach(parent.getSons()::add);
//保存父项并触发添加子项的创建/删除已删除的现有子项
parentRepository.save(父级);
这在很大程度上取决于父对象中的映射
-当您使用级联类型
和孤立删除
时,您根本不需要添加/保存/删除任何子对象,您只需确保对象设置正确,然后保存父对象,然后休眠即可完成其余操作(如果更改,请保存现有的子项,添加新的子项,删除新的孤立子项)。也就是说,请添加父项
和子项
的代码,否则这只是猜测。@Smutje用实体更新了问题
@Entity(name = "parents")
public class Parent {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
private String title;
@OneToMany(mappedBy = "parent", cascade = CascadeType.ALL, fetch = FetchType.EAGER)
private List<Son> sons;
}
@Entity(name = "sons")
public class Son {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private String name;
@ManyToOne
@JoinColumn(name = "parentId")
private Parent parent;
}
@Entity(name = "parents")
public class Parent {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
private String title;
@OneToMany(mappedBy = "parent", cascade = CascadeType.ALL, fetch = FetchType.EAGER, orphanRemoval = true)
private List<Son> sons;
}
Parent parent = findById(id);
Map<String, Son> addedSons = toHashMap(dto.getSons());
// Remove existing sons that are not part of the update
parent.getSons().removeIf(existingSon -> !addedSons.containsKey(existingSon.getUniqueString()));
// Add new sons
addedSons.forEach(parent.getSons()::add);
// Save parent and trigger creating of added sons/deletion of removed existing sons
parentRepository.save(parent);