安卓Java新手求助：将Firebase Storage图片存入指定用户Firestore

你已经实现了图片上传到Storage，接下来只需要在上传成功后获取图片的下载URL，然后将这个URL和用户信息一起写入Firestore即可完成关联。以下是具体步骤和修改后的代码：

步骤说明 #

• 确保用户已通过Firebase Auth登录，这样才能获取唯一的用户ID来关联数据
• 上传图片成功后，调用getDownloadUrl()获取图片的永久访问链接
• 在Firestore中创建集合（比如userTestResults），将用户ID、图片URL、上传时间等信息存入文档

修改后的完整代码 #

public class BloodTestActivity extends AppCompatActivity {

    ImageView imageSelected;
    Button btn_uploadImage, btn_sendImage;
    Uri uri;
    StorageReference storageReference;
    ProgressDialog progressDialog;
    // 添加Firestore引用
    FirebaseFirestore db;
    // 当前用户
    FirebaseUser currentUser;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_blood_test);

        imageSelected = findViewById(R.id.viewSelectedImage);
        btn_uploadImage = findViewById(R.id.btn_uploadImage);
        btn_sendImage = findViewById(R.id.btn_sendImage);

        // 初始化Firestore和当前用户
        db = FirebaseFirestore.getInstance();
        currentUser = FirebaseAuth.getInstance().getCurrentUser();

        btn_uploadImage.setOnClickListener(v -> UploadImage());
        btn_sendImage.setOnClickListener(v -> sendImage());
    }

    private void sendImage() {
        // 先检查用户是否登录
        if (currentUser == null) {
            Toast.makeText(this, "请先登录账号", Toast.LENGTH_SHORT).show();
            return;
        }

        progressDialog = new ProgressDialog(this);
        progressDialog.setTitle("Sending test result...");
        progressDialog.show();

        SimpleDateFormat format = new SimpleDateFormat("yyyy_MM_dd_HH_mm_ss", Locale.CANADA);
        Date now = new Date();
        String fileName = format.format(now);
        storageReference = FirebaseStorage.getInstance().getReference("images/" + fileName);

        storageReference.putFile(uri)
                .addOnSuccessListener(taskSnapshot -> {
                    // 上传成功后获取图片下载URL
                    storageReference.getDownloadUrl().addOnSuccessListener(downloadUri -> {
                        // 准备要存入Firestore的数据
                        Map<String, Object> testResult = new HashMap<>();
                        testResult.put("userId", currentUser.getUid());
                        testResult.put("imageUrl", downloadUri.toString());
                        testResult.put("uploadTime", new Timestamp(now));
                        testResult.put("fileName", fileName);

                        // 写入Firestore，这里可以用用户ID作为文档ID，或者自动生成
                        db.collection("userTestResults")
                                .add(testResult)
                                .addOnSuccessListener(documentReference -> {
                                    imageSelected.setImageURI(null);
                                    Toast.makeText(BloodTestActivity.this, "上传并关联成功!", Toast.LENGTH_SHORT).show();
                                    if (progressDialog.isShowing())
                                        progressDialog.dismiss();
                                })
                                .addOnFailureListener(e -> {
                                    Toast.makeText(BloodTestActivity.this, "关联数据库失败: " + e.getMessage(), Toast.LENGTH_SHORT).show();
                                    if (progressDialog.isShowing())
                                        progressDialog.dismiss();
                                });
                    }).addOnFailureListener(e -> {
                        Toast.makeText(BloodTestActivity.this, "获取图片链接失败: " + e.getMessage(), Toast.LENGTH_SHORT).show();
                        if (progressDialog.isShowing())
                            progressDialog.dismiss();
                    });
                })
                .addOnFailureListener(e -> {
                    if (progressDialog.isShowing())
                        progressDialog.dismiss();
                    Toast.makeText(BloodTestActivity.this, "上传图片失败!", Toast.LENGTH_SHORT).show();
                });
    }

    private void UploadImage() {
        Dexter.withContext(this)
                .withPermission(Manifest.permission.READ_EXTERNAL_STORAGE)
                .withListener(new PermissionListener() {
                    @Override
                    public void onPermissionGranted(PermissionGrantedResponse permissionGrantedResponse) {
                        Intent intent = new Intent();
                        intent.setType("image/*");
                        intent.setAction(Intent.ACTION_GET_CONTENT);
                        startActivityForResult(intent, 101);
                    }

                    @Override
                    public void onPermissionDenied(PermissionDeniedResponse permissionDeniedResponse) {
                        Toast.makeText(BloodTestActivity.this, "Permission Denied", Toast.LENGTH_SHORT).show();
                    }

                    @Override
                    public void onPermissionRationaleShouldBeShown(PermissionRequest permissionRequest, PermissionToken permissionToken) {
                        permissionToken.cancelPermissionRequest();
                    }
                }).check();
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == 101 && resultCode == RESULT_OK){
            uri = data.getData();
            imageSelected.setImageURI(uri);
        }
    }
}

关键修改点 #

1. 添加Firestore和Auth引用：初始化FirebaseFirestore和FirebaseUser，用于获取用户ID和操作数据库
2. 用户登录校验：在上传前检查用户是否登录，避免无用户ID的情况
3. 获取下载URL：图片上传成功后调用getDownloadUrl()获取可访问的图片链接
4. 写入Firestore：将用户ID、图片URL、上传时间等数据存入集合，完成图片与用户的关联

注意事项 #

• 确保你的项目已经添加了Firestore依赖，在build.gradle中检查是否有：

  implementation 'com.google.firebase:firebase-firestore:24.11.0'
  implementation 'com.google.firebase:firebase-auth:22.3.1'
  

• 可以根据需求调整Firestore的集合名称和存储的字段，比如添加检测类型、备注等信息
• 处理好各种失败回调，给用户明确的错误提示

内容的提问来源于stack exchange，提问作者Fonel1