问题描述
我是FIrebase的新手，我有两个问题可能会被连接。第一个是保存事件列表。
//创建事件
TVEvent tvEvent = new TVEvent（etTitle。 。的getText（）的toString（））;
User host = ResourceManager.getUser（）;
String date = etDate.getText（）。toString（）;
String location = etLocation.getText（）。toString（）;
TVSet tvset = ResourceManager.getUser（）。getTvSets（）。get（0）;
Event ev = new Event（tvEvent，host，date，location，tvset）;
ResourceManager.addEvent（ev）;
mDatabase.child（events）。child（host.getId（））。setValue（ResourceManager.getEvents（））; // getEvents（）返回事件列表
这就是我在控制台
问题是tvevent和tv集比这些属性有更多的属性。当我调试了解为什么tvevent是创建的所有属性有点奇怪。但现在，我不知道这是否是一个问题，因为我无法从数据库中检索tvset和tvevent。当我做下面的事情时，我得到了空。
mDatabase.child（events）。addListenerForSingleValueEvent（
new ValueEventListener（）{
@Override
public void onDataChange（DataSnapshot dataSnapshot）{
System.out.println（Cheering for events）;
// GenericTypeIndicator< List< （DataSnapshot messageSnapshot：dataSnapshot（））;事件>> t = new GenericTypeIndicator< List< Event>>（）{};
// List< Event> e = dataSnapshot.getValue（t）;
（））{
GenericTypeIndicator< List< Event>> t = new GenericTypeIndicator< List< Event>>（）{};
List< Event> list = messageSnapshot.getValue ;
if（list！= null）{
for（Event ev：list）{
System.out.println（Event found）;
ResourceManager.addEvent EV）;
@Override
public void onCancelled（DatabaseError databaseError）{
}
}）;
我不知道为什么这些值为空，因为我可以看到它们不在firebase中安慰。那么是什么问题？
pre $ @ $ c $ @ $ @ $ $ $ $ $ $ $ $ $
私人TVEvent tvEvent;
私人用户主机;
私人日期日期;
私人字符串位置;
private TVSet tvSet;
私人列表<使用者>主治;
$ b public Event（）{
}
$ b $ public Event（TVEvent tvEvent，User host，String date，String location，TVSet tvset）{
this .tvSet = tvset;
this.tvEvent = tvEvent;
this.host = host;
try {
this.date = new SimpleDateFormat（dd / MM / yyyy）。parse（date）;
} catch（ParseException e）{
e.printStackTrace（）;
}
this.location = location;
attending = new ArrayList<>（）;
}
public User getHost（）{
return host;
}
public String getLocation（）{
return location;
}
public TVSet getTVSet（）{
return tvSet;
}
public Date getDate（）{
return date;
}
public TVEvent getTVEvent（）{
return tvEvent;
}
public void addAttending（User user）{
attending.add（user）;
}
public List< User> getAttending（）{
返回参加;
$因为TVSet和TVEvent都没有得到正确的反序列化将只发布其中的一个：
@IgnoreExtraProperties
public class TVSet {
private字符串标题;
private String imageFile;
//私人位图图片;
public TVSet（）{
}
public TVSet（String title）{
this.title = title;
}
public TVSet（位图图片）{
imageFile = compressImage（picture）;
}
public void setTitle（String title）{
this.title = title;
}
public String getTitle（）{
return title;
private String compressImage（Bitmap image）{
ByteArrayOutputStream bYtE = new ByteArrayOutputStream（）;
image.compress（Bitmap.CompressFormat.PNG，100，bYtE）;
//image.recycle（）;
byte [] byteArray = bYtE.toByteArray（）;
String imageFile = Base64.encodeToString（byteArray，Base64.DEFAULT）;
返回imageFile;
$ b @Exclude
public Bitmap getImage（）{
byte [] encodedString = Base64.decode（imageFile，Base64.DEFAULT）;
位图位图= BitmapFactory.decodeByteArray（decodedString，0，decodedString.length）;
返回位图;
public String getImageFile（）{
return imageFile;
抱歉格式不正确。任何帮助表示赞赏。
尝试使用
Map< String，String> data =（HashMap< String，String>）dataSnapshot.getValue（）;
而不是
GenericTypeIndicator< List< Event>> t = new GenericTypeIndicator< List< Event>>（）{};
列表< Event> list = messageSnapshot.getValue（t）;
I am new to FIrebase and I have 2 problems with it that might be connected. First one is when saving my list of events.
//creating event
TVEvent tvEvent = new TVEvent(etTitle.getText().toString());
User host = ResourceManager.getUser();
String date = etDate.getText().toString();
String location = etLocation.getText().toString();
TVSet tvset = ResourceManager.getUser().getTvSets().get(0);
Event ev = new Event(tvEvent, host, date, location, tvset);
ResourceManager.addEvent(ev);
mDatabase.child("events").child(host.getId()).setValue(ResourceManager.getEvents()); //getEvents() returns a list of events
this is what I get in the console
The problem is that tvevent and tv set have more attributes than these ones. When I debugged to find out why is that tvevent was created with all of its attributes which was a little strange. For now, however I don't know whether this is a problem as I cannot retrieve the tvset and tvevent from the database. When i do the following I get the to be null.
mDatabase.child("events").addListenerForSingleValueEvent(
new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
System.out.println("Cheking for events");
//GenericTypeIndicator<List<Event>> t = new GenericTypeIndicator<List<Event>>() {};
//List<Event> e = dataSnapshot.getValue(t);
for (DataSnapshot messageSnapshot: dataSnapshot.getChildren()) {
GenericTypeIndicator<List<Event>> t = new GenericTypeIndicator<List<Event>>() {};
List<Event> list = messageSnapshot.getValue(t);
if (list != null) {
for (Event ev : list) {
System.out.println("Event found");
ResourceManager.addEvent(ev);
}
}
}
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
I don't know why these values are null as I can see that they are not in the firebase console. So what is the problem?
@IgnoreExtraProperties
public class Event {
private TVEvent tvEvent;
private User host;
private Date date;
private String location;
private TVSet tvSet;
private List<User> attending;
public Event(){
}
public Event(TVEvent tvEvent, User host, String date, String location, TVSet tvset){
this.tvSet = tvset;
this.tvEvent = tvEvent;
this.host = host;
try {
this.date = new SimpleDateFormat("dd/MM/yyyy").parse(date);
} catch (ParseException e) {
e.printStackTrace();
}
this.location = location;
attending = new ArrayList<>();
}
public User getHost() {
return host;
}
public String getLocation() {
return location;
}
public TVSet getTVSet() {
return tvSet;
}
public Date getDate() {
return date;
}
public TVEvent getTVEvent() {
return tvEvent;
}
public void addAttending(User user){
attending.add(user);
}
public List<User> getAttending(){
return attending;
}
}
As both TVSet and TVEvent does not get deserialised properly I will post only one of them:
@IgnoreExtraProperties
public class TVSet {
private String title;
private String imageFile;
//private Bitmap picture;
public TVSet(){
}
public TVSet(String title){
this.title = title;
}
public TVSet(Bitmap picture){
imageFile = compressImage(picture);
}
public void setTitle(String title){
this.title = title;
}
public String getTitle() {
return title;
}
private String compressImage(Bitmap image){
ByteArrayOutputStream bYtE = new ByteArrayOutputStream();
image.compress(Bitmap.CompressFormat.PNG, 100, bYtE);
//image.recycle();
byte[] byteArray = bYtE.toByteArray();
String imageFile = Base64.encodeToString(byteArray, Base64.DEFAULT);
return imageFile;
}
@Exclude
public Bitmap getImage() {
byte[] decodedString = Base64.decode(imageFile, Base64.DEFAULT);
Bitmap bitmap = BitmapFactory.decodeByteArray(decodedString, 0, decodedString.length);
return bitmap;
}
public String getImageFile(){
return imageFile;
}
}
Sorry for the bad formatting. Any help is appreciated.
try to use
Map<String, String> data= (HashMap<String, String>)dataSnapshot.getValue();
instead of
GenericTypeIndicator<List<Event>> t = new GenericTypeIndicator<List<Event>>() {}; List<Event> list = messageSnapshot.getValue(t);
这篇关于Google Firebase序列化/反序列化的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！