Java arrayList仅在onCompletelistener内部更新,不在其外部更新
我试图读取云firestore中的数据,并将其放入一个名为“urlList”的数组中。arrayList在onComplete中,如果我将数组记录在那里,它就会工作(它填充了它假定拥有的数据)。每当我在onComplete之外记录arrayList时,数组都是空的。问题似乎出在onCompletelistener上,但我找不到哪里出了问题/如何避免问题。我添加了数字5和6的日志来检查问题所在,onCreate中的日志确实看到了5,但没有看到6Java arrayList仅在onCompletelistener内部更新,不在其外部更新,java,android,arraylist,scope,Java,Android,Arraylist,Scope,我试图读取云firestore中的数据,并将其放入一个名为“urlList”的数组中。arrayList在onComplete中,如果我将数组记录在那里,它就会工作(它填充了它假定拥有的数据)。每当我在onComplete之外记录arrayList时,数组都是空的。问题似乎出在onCompletelistener上,但我找不到哪里出了问题/如何避免问题。我添加了数字5和6的日志来检查问题所在,onCreate中的日志确实看到了5,但没有看到6 public static ArrayList&l
public static ArrayList<String> urlList = new ArrayList<String>();
public static ArrayList<String> groupList = new ArrayList<String>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_middel_scherm);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
ConstraintLayout layout = (ConstraintLayout) findViewById(R.id.imageLayout);
setSupportActionBar(toolbar);
db = FirebaseFirestore.getInstance();
mAuth = FirebaseAuth.getInstance();
CurrentUser = FirebaseAuth.getInstance().getCurrentUser().getUid();
mAuthListener = new FirebaseAuth.AuthStateListener() {
@Override
public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) {
if (firebaseAuth.getCurrentUser() == null) {
startActivity(new Intent(MiddelScherm.this, LoginScherm.class));
}
}
};
ivImage = (ImageView) findViewById(R.id.ivImage);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
SelectImage();
}
});
databaseDownload();
Log.d(TAG, "egregergegre");
Log.d(TAG, String.valueOf(urlList));
Log.d(TAG, "egregergegre");
showEachImage(layout);
}
public void showEachImage(ConstraintLayout layout) {
for (String element: urlList) {
ImageView image = new ImageView(this);
image.setLayoutParams(new android.view.ViewGroup.LayoutParams(80,60));
image.setMaxHeight(20);
image.setMaxWidth(20);
Picasso.get().load(element).into(image);
layout.addView(image);
}
}
public void databaseDownload() {
urlList.add("5");
db.collection("user").document(CurrentUser).collection("meta-data")
.get()
.addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() {
@Override
public void onComplete(@NonNull Task<QuerySnapshot> task) {
if (task.isSuccessful()) {
urlList.add("6");
for (DocumentSnapshot document : task.getResult()) {
String imageValue = document.getString("URL");
urlList.add(imageValue);
Log.d(TAG, String.valueOf(urlList));
}
} else {
Log.w(TAG, "Error getting documents.", task.getException());
}
}
});
db.collection("user").document(CurrentUser).collection("Group")
.get()
.addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() {
@Override
public void onComplete(@NonNull Task<QuerySnapshot> task) {
if (task.isSuccessful()) {
for (DocumentSnapshot document : task.getResult()) {
String groupValue = document.getString("Group");
groupList.add(groupValue);
Log.d(TAG, String.valueOf(groupList));
}
} else {
Log.w(TAG, "Error getting documents.", task.getException());
}
}
});
}
publicstaticarraylisturlist=newarraylist();
public static ArrayList groupList=new ArrayList();
@凌驾
创建时受保护的void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_middel_scherm);
Toolbar Toolbar=(Toolbar)findViewById(R.id.Toolbar);
ConstraintLayout布局=(ConstraintLayout)findViewById(R.id.imageLayout);
设置支持操作栏(工具栏);
db=FirebaseFirestore.getInstance();
mAuth=FirebaseAuth.getInstance();
CurrentUser=FirebaseAuth.getInstance().getCurrentUser().getUid();
mAuthListener=new FirebaseAuth.AuthStateListener(){
@凌驾
AuthStateChanged上的公共void(@NonNull FirebaseAuth FirebaseAuth){
如果(firebaseAuth.getCurrentUser()==null){
startActivity(新意图(MiddelScherm.this,LoginScherm.class));
}
}
};
ivImage=(ImageView)findViewById(R.id.ivImage);
FloatingActionButton fab=(FloatingActionButton)findViewById(R.id.fab);
fab.setOnClickListener(新视图.OnClickListener(){
@凌驾
公共void onClick(视图){
选择image();
}
});
数据库下载();
Log.d(标签“egreergegre”);
Log.d(TAG,String.valueOf(urlist));
Log.d(标签“egreergegre”);
展示图片(布局);
}
公共空间显示图标(约束布局){
for(字符串元素:urlList){
ImageView图像=新的ImageView(此);
setLayoutParams(新的android.view.ViewGroup.LayoutParams(80,60));
图像。设置最大高度(20);
image.setMaxWidth(20);
毕加索.get().load(元素).into(图像);
布局。添加视图(图像);
}
}
公共void数据库下载(){
URL列表。添加(“5”);
数据库集合(“用户”).文档(当前用户).集合(“元数据”)
.get()
.addOnCompleteListener(新的OnCompleteListener(){
@凌驾
未完成的公共void(@NonNull任务){
if(task.issusccessful()){
URL列表。添加(“6”);
对于(DocumentSnapshot文档:task.getResult()){
String imageValue=document.getString(“URL”);
添加(imageValue);
Log.d(TAG,String.valueOf(urlist));
}
}否则{
Log.w(标记“获取文档时出错”,task.getException());
}
}
});
db.集合(“用户”).文档(当前用户).集合(“组”)
.get()
.addOnCompleteListener(新的OnCompleteListener(){
@凌驾
未完成的公共void(@NonNull任务){
if(task.issusccessful()){
对于(DocumentSnapshot文档:task.getResult()){
String groupValue=document.getString(“组”);
groupList.add(groupValue);
Log.d(TAG,String.valueOf(groupList));
}
}否则{
Log.w(标记“获取文档时出错”,task.getException());
}
}
});
}
我甚至尝试将公共void showEachImage(ConstraintLayout布局)放在onCompletelistener中,但它在:ImageView image=new ImageView(this)行的“this”处出现错误:因此我也放弃了这种结构
public void databaseDownload() {
urlList.add("5");
db.collection("user").document(CurrentUser).collection("meta-data")
.get()
.addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() {
@Override
public void onComplete(@NonNull Task<QuerySnapshot> task) {
if (task.isSuccessful()) {
urlList.add("6");
for (DocumentSnapshot document : task.getResult()) {
String imageValue = document.getString("URL");
ImageView image = new ImageView(this);
image.setLayoutParams(new
android.view.ViewGroup.LayoutParams(80,60));
image.setMaxHeight(20);
image.setMaxWidth(20);
Picasso.get().load(imageValue).into(image);
layout.addView(image);
Log.d(TAG, String.valueOf(urlList));
}
} else {
Log.w(TAG, "Error getting documents.", task.getException());
}
}
});
db.collection("user").document(CurrentUser).collection("Group")
.get()
.addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() {
@Override
public void onComplete(@NonNull Task<QuerySnapshot> task) {
if (task.isSuccessful()) {
for (DocumentSnapshot document : task.getResult()) {
String groupValue = document.getString("Group");
groupList.add(groupValue);
Log.d(TAG, String.valueOf(groupList));
}
} else {
Log.w(TAG, "Error getting documents.", task.getException());
}
}
});
publicsvoiddatabasedownload(){
URL列表。添加(“5”);
数据库集合(“用户”).文档(当前用户).集合(“元数据”)
.get()
.addOnCompleteListener(新的OnCompleteListener(){
@凌驾
未完成的公共void(@NonNull任务){
if(task.issusccessful()){
URL列表。添加(“6”);
对于(DocumentSnapshot文档:task.getResult()){
String imageValue=document.getString(“URL”);
ImageView图像=新的ImageView(此);
image.setLayoutParams(新
android.view.ViewGroup.LayoutParams(80,60));
图像。设置最大高度(20);
image.setMaxWidth(20);
Picasso.get().load(imageValue).into(image);
布局。添加视图(图像);
Log.d(TAG,String.valueOf(urlist));
}
}否则{
Log.w(标记“获取文档时出错”,task.getException());
}
}
});
db.集合(“用户”).文档(当前用户).集合(“组”)
.get()
.addOnCompleteListener(新的OnCompleteListener(){
@凌驾
未完成的公共void(@NonNull任务){
if(task.issusccessful()){
对于(DocumentSnapshot文档:task.getResult()){
String groupValue=document.getString(“组”);
groupList.add(groupValue);
Log.d(TAG,String.valueOf(groupList));
}
}否则{
Log.w(标记“获取文档时出错”,task.getException());