在Morphia中，我如何更新ArrayList中的一个嵌入对象
使用Mongodb和Morphia一起真的很新，并看到许多高级答案如何做到这一点。
如果有可能我想简单地做这个@Embedded对象
包含Files对象的fileObjects 。
我无法更新Files的字段。
我想只更新一个字段f.ex String fileHash 。
@Entity public class BatchData { @Id private ObjectId id; @Embedded public ArrayList fileObjects = new ArrayList(); }
更新..在Morphia阅读维基更新不要“真的”说如何只在数组包含这样的Integer时才这样做：
@Embedded List roomNumbers = new ArrayList();
以下是我到目前为止的尝试：
mongo.createUpdateOperations(BatchData.class).add("fileObjects", Files, false);
此代码插入的Files已在mongo中。 false不会检测到并将其插入数组的末尾。 我可以在Files添加唯一ID，以便检测到数据中是否存在要插入的Files ，然后只更新它？
@Embedded public class Files { public Files() { } public int position; public String fileName = ""; public String fileHash = ""; public Files(int pos, String fileName, String fileHash) { this.position = pos; this.fileName = fileName; this.fileHash = fileHash; } }
阅读其他答案，如morphia-mongodb-access，但他已经拥有了
@Entity BlogEntry（参见链接）在mongo之外的POJO中。 也许我必须这样做？
拉出来，改变它并保存回来？
为任何人的喜悦回答我自己的问题。
我想我解决了它不确定。
当fileObjects有很多Files时，看起来它正在测试。
正确更新了正确的fileHash 。
UpdateOperationsupdateOperations=mongo.createUpdateOperations (BatchData.class) .disableValidation().set("fileObjects.$.fileHash",hash).enableVali..; mongo.update(mongo.createQuery(BatchData.class) .filter("uuid",theBatch.uuid) .filter("fileObjects.fileName","theFileName"),updateOperations);
在我的情况下，我能够使用removeAll方法：
UpdateOperations ops = ds.createUpdateOperations( MyType.class).removeAll("myEmbeddedList", "thevalue"); ds.update(ds.find(MyType.class).get(), ops);
假设MyType具有List myEmbeddedList字段; 并且有一个vlue“thevalue”要从列表中删除。
我只是（是的，现在）用这种方式解决了这个问题：我用查询得到了根类
List fileList = mDatastore.createQuery(File.class).field("_id").equal(new ObjectId(ID)).asList();
然后，我在这个根类中实现了CRUD操作（我将发布我的根类）：
@Entity public class Applications extends BaseEntity{ private String name; private String owner; private String version; @Embedded List resources = new ArrayList<>(); @Embedded List activities = new ArrayList<>(); @Embedded List components = new ArrayList<>(); public Applications() { } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getOwner() { return owner; } public void setOwner(String owner) { this.owner = owner; } public String getVersion() { return version; } public Applications setVersion(String version) { this.version = version; return this; } public List getResources() { return resources; } public Applications setResources(List resources) { this.resources = resources; return this; } public Resources getResourcesByName(String name) { for(Resources resource : this.resources){ if (resource.getName().equals(name)) return resource; } return null; } public boolean containsResourceByName(String name) { for(Resources resource : this.resources){ if (resource.getName().equals(name)) return true; } return false; } public Applications addResource(Resources newResource) { if (!containsResourceByName(newResource.getName())) { this.resources.add(newResource); } return this; } public Applications removeResource(Resources newResource) { if (containsResourceByName(newResource.getName())) { this.resources.remove(getResourcesByName(newResource.getName())); } return this; } public Applications removeResourceByName(String name) { if (containsResourceByName(name)) { this.resources.remove(getResourcesByName(name)); } return this; } public List getActivities() { return activities; } public Applications setActivities(List activities) { this.activities = activities; return this; } public Activities getActivityByName(String name) { for(Activities activity : this.activities){ if (activity.getName().equals(name)) return activity; } return null; } public boolean containsActivityByName(String name) { for(Activities activity : this.activities){ if (activity.getName().equals(name)) return true; } return false; } public Applications addActivity(Activities newActivity) { if (!containsActivityByName(newActivity.getName())) { this.activities.add(newActivity); } return this; } public Applications removeActivity(Activities newActivity) { if (containsActivityByName(newActivity.getName())) { this.activities.remove(getActivityByName(newActivity.getName())); } return this; } public Applications removeActivityByName(String name) { if (containsActivityByName(name)) { this.activities.remove(getActivityByName(name)); } return this; } public List getComponents() { return components; } public Applications setComponents(List components) { this.components = components; return this; } public Components getComponentByName(String name) { for(Components component : this.components){ if (component.getName().equals(name)) return component; } return null; } public boolean containsComponentByName(String name) { for(Components component : this.components){ if (component.getName().equals(name)) return true; } return false; } public Applications addComponent(Components newComponent) { if (!containsComponentByName(newComponent.getName())) { this.components.add(newComponent); } return this; } public Applications removeComponent(Components newComponent) { if (containsComponentByName(newComponent.getName())) { this.components.remove(getComponentByName(newComponent.getName())); } return this; } public Applications removeComponentByName(String name) { if (containsComponentByName(name)) { this.components.remove(getComponentByName(name)); } return this; } public Applications updateComponentByName(String name, String newName) { if (containsComponentByName(name)) { getComponentByName(name).setName(newName); } return this; } @Override public String toString() { try { JSONObject jsonObject = new JSONObject(); jsonObject.put(DatabaseModel.ApplicationsModel.FIELD_ID, id); jsonObject.put(DatabaseModel.ApplicationsModel.FIELD_NAME, name); jsonObject.put(DatabaseModel.ApplicationsModel.FIELD_OWNER, owner); jsonObject.put(DatabaseModel.ApplicationsModel.FIELD_VERSION, version); jsonObject.put(DatabaseModel.ActivitiesModel.DOCUMENT_NAME, activities); jsonObject.put(DatabaseModel.ResourcesModel.DOCUMENT_NAME, resources); jsonObject.put(DatabaseModel.ComponentsModel.DOCUMENT_NAME, components); return jsonObject.toString(); } catch (JSONException e) { // TODO Auto-generated catch block e.printStackTrace(); return "Something went wrong"; } }
有一次，我修改了我的应用程序数据，我只需将它保存到主程序中的mongodb：
mDatastore.save(mApplications);
希望这可以帮助你，再见！