如何编辑＆＃34; user_mobile＆＃34;值

Question

我想编辑＆＃34; user_mobile＆＃34;和＆＃34; user_blood＆＃34;。

我试过这段代码。

 mAuth = FirebaseAuth.getInstance();
        String online_user_id = mAuth.getCurrentUser().getUid();
        getUserDataReference = FirebaseDatabase.getInstance().getReference().child("Users").child(online_user_id);

getUserDataReference.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {
                //dataSnapshot.get

                String name = dataSnapshot.child("user_name").getValue().toString();
                String status = dataSnapshot.child("user_status").getValue().toString();
                String image = dataSnapshot.child("user_image").getValue().toString();
                mobile = dataSnapshot.child("user_mobile").getValue().toString();
                String thumb_image = dataSnapshot.child("user_thumb_image").getValue().toString();

                settingDisplayName.setText(name);
                settingDisplayStatus.setText(status);

                if (!image.equals("default_profile"))
                {
                    Picasso.with(SettingActivity.this).load(image).placeholder(R.drawable.default_profile).into(settingsDisplayImage);
                }

            }

            @Override
            public void onCancelled(DatabaseError databaseError) {

            }
        });

以下是错误。

FATAL EXCEPTION: main
                                                                      Process: com.logictex.bloodbank, PID: 2486
                                                                      java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String java.lang.Object.toString()' on a null object reference
                                                                          at com.logictex.bloodbank.SettingActivity$1.onDataChange(SettingActivity.java:77)
                                                                          at com.google.android.gms.internal.zzbmz.zza(Unknown Source)
                                                                          at com.google.android.gms.internal.zzbnz.zzYj(Unknown Source)
                                                                          at com.google.android.gms.internal.zzboc$1.run(Unknown Source)
                                                                          at android.os.Handler.handleCallback(Handler.java:739)
                                                                          at android.os.Handler.dispatchMessage(Handler.java:95)
                                                                          at android.os.Looper.loop(Looper.java:135)
                                                                          at android.app.ActivityThread.main(ActivityThread.java:5254)
                                                                          at java.lang.reflect.Method.invoke(Native Method)
                                                                          at java.lang.reflect.Method.invoke(Method.java:372)
                                                                          at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
                                                                          at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)

Answer 1

DatabaseReference xyz= 
FirebaseDatabase.getInstance().getReference().child("Users").child(online_user_id).child("user_mobile");
xyz.setValue("set_desired vaule");

对use_blood做同样的事情

Answer 2

可能是您的路径document.getElementById("demo1").innerHTML = parseInt(xhttp.getResponseHeader("Content-Length")); 不存在。

FirebaseDatabase.getInstance().getReference().child("Users").child(online_user_id);

Answer 3

要解决此问题，您需要使用以下代码：

DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();

DatabaseReference user_mobileRef = rootRef.child("Users").child(user_blood).child(online_user_id).child("user_mobile");
user_mobileRef.setValue("YourNewValue");

DatabaseReference user_bloodRef = rootRef.child("Users").child(user_blood).child(online_user_id).child("user_blood");
user_bloodRef.setValue("YourNewValue");