java - 通过 Firestore 仅存储当前登录用户的数据

Question

当我使用用户 account1 登录并上传数据时，让我们说“你好”并获取它，我可以看到“你好”这个词(这就是我想要的)。但是当我注销并使用用户 account2 登录时，每当我单击获取时，它都会显示“你好”。但它不应该显示，因为这是用户 account1 输入的。所以它应该只显示登录用户输入的数据。

如何更改我的代码以允许数据仅由当前登录的用户存储和检索？

下面是代码:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    FirebaseApp.initializeApp(this);
    setContentView(R.layout.activity_ichild);

    String uid = FirebaseAuth.getInstance().getCurrentUser().getUid();
    FirebaseFirestore rootRef = FirebaseFirestore.getInstance();
    DocumentReference uidRef = rootRef.collection("RootCollection").document(uid);
    POJO pojo = new POJO();
    uidRef.set(pojo);


    fetch=findViewById(R.id.fetchDocument);


    firestore = FirebaseFirestore.getInstance();

    upload =findViewById(R.id.uploadText);

    upload.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {

            POJO pojo = new POJO();
            pojo.setValue("Hello World");

            //below code creates collection, creates a inner doc. and uploads the value (pojo)

            firestore.collection("RootCollection").document("MyDoc")
                    .set(pojo).addOnSuccessListener(new OnSuccessListener<Void>() {
                @Override
                public void onSuccess(Void aVoid) {


                    //gets called if upload is successful
                    Toast.makeText(ichild.this,"Upload is successful", Toast.LENGTH_SHORT).show();

                }
            }).addOnFailureListener(new OnFailureListener() {
                @Override
                public void onFailure(@NonNull Exception e) {
                    Toast.makeText(ichild.this,"Upload is not successful" + e.getMessage(), Toast.LENGTH_SHORT).show();
                }
            });

        }
    });

Answer 1

因为每次您都将数据加载到同一个文档中

firestore.collection("RootCollection").document("MyDoc")

相反，您可以使用在路径中引用 id 的文档，所以使用这个

uidRef.set(pojo).addOnSuccessListener(new OnSuccessListener<Void>() {

代替

firestore.collection("RootCollection").document("MyDoc")
                    .set(pojo).addOnSuccessListener(new OnSuccessListener<Void>() {

并删除它，只设置空对象

POJO pojo = new POJO();
uidRef.set(pojo);