我需要遍历Firebase架构以获取每个workouts的数据并将其显示在RecyclerView中。
现在，我无法使用侦听器遍历Firebase中的Schema，也无法通过名为Program的POJO类获取它。
Firebase的JSON
{
"subscriptions" : {
"han@gmail,com" : {
"-KDnhRwHjssOejrqyenP" : {
"category" : "Strength",
"goal" : "This workout can be done while on the phone!",
"length" : 1,
"title" : "Hello Workouts",
"weeks" : {
"week1" : [ "High Knees", "Jumping Jacks", "Wall sit", "Pushups", "Sit-ups", "Step ups", "Squats", "Tricep dips on chair", "Plank", "High Knees running in place", "Lunges", "Pushup and rotation", "Side plank (alternate per round)", "Alternating Push-Up Plank", "Chest Expander", "Diamond Push-ups", "Dive Bomber Push-ups", "Butt Kickers", "Lying Triceps Lifts", "One Arm Side Push-up", "Overhead Arm Clap", "Overhead Press", "Power Circles", "Push-up and Rotation", "T Push-ups", "Reverse Plank", "Spiderman Push-up", "T Raise", "Tricep Dips", "Wall Push-ups", "Wide Arm Push-ups", "Burpees" ]
}
},
"-KDni3TN4NMyGXePyp92" : {
"category" : "Strength",
"goal" : "This workout can be done by a BABUJI",
"length" : 1,
"title" : "Indian Workouts",
"weeks" : {
"week1" : [ "Diamond Pushups", "Jackknives", "Plyo Lunges", "Plyo Squats", "Single leg plank (alternate per round)", "Plyo Lunges", "Pushup and rotation", "Weighted side plank (alternate per round)", "Alternating Push-Up Plank", "Chest Expander", "Diamond Push-ups", "Dive Bomber Push-ups", "One Arm Side Push-up", "Overhead Press", "Push-up and Rotation", "T Push-ups", "Spiderman Push-up", "Wide Arm Push-ups", "Burpee Pushups" ]
}
}
},
"obama@gmsil,com" : {
"-KDnfjROKeFAL9wccsxY" : {
"category" : "Mobility",
"goal" : "afternoon body weight workout",
"length" : 1,
"title" : "Afternoon HiiT",
"weeks" : {
"week1" : [ "High Knees", "Squats", "Lunges", "Diamond Push-ups", "Lying Triceps Lifts" ]
}
},
"-KDps90Dn6XtJc6Co00b" : {
"category" : "Strength",
"goal" : "goal",
"length" : 1,
"title" : "title",
"weeks" : {
"week1" : [ "Diamond Pushups", "Jackknives", "Plyo Lunges", "Plyo Squats", "Single leg plank (alternate per round)", "Plyo Lunges", "Pushup and rotation", "Weighted side plank (alternate per round)", "Alternating Push-Up Plank", "Chest Expander", "Diamond Push-ups", "Dive Bomber Push-ups", "One Arm Side Push-up", "Overhead Press", "Push-up and Rotation", "T Push-ups", "Spiderman Push-up", "Wide Arm Push-ups", "Burpee Pushups" ]
}
}
}
}
}
侦听器代码
public void FB(){
ref.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot snapshot) {
for (DataSnapshot postSnapshot: snapshot.getChildren()) {
System.out.println(postSnapshot.getValue());
//Program post = proSnapshot.getValue(Program.class);
}
}
@Override
public void onCancelled(FirebaseError firebaseError) {
System.out.println("The read failed: " + firebaseError.getMessage());
}
});
}
LOGCAT
03-28 08：52：53.966 23584-23584 / com.android.sam I / System.out：{-KDni3TN4NMyGXePyp92 = {weeks = {week1 = [Diamond Pushups，Jackknives，Plyo Lunges，Plyo Squats，单腿板（备用）每轮），Plyo刺针，俯卧撑和旋转，配重侧板（每轮备用），交替俯卧撑板，扩胸器，钻石俯卧撑，潜水轰炸俯卧撑，单臂俯卧撑，高架俯卧撑，俯卧撑和旋转，T俯卧撑，蜘蛛侠俯卧撑，宽臂俯卧撑，Burpee俯卧撑]}，标题=印度锻炼，类别=力量，长度= 1，目标=此锻炼可以由BABUJI完成}，-KDnhRwHjssOejrqyenP = {weeks = {week1 = [高膝盖，跳起的杰克，坐在墙壁上，俯卧撑，仰卧起坐，俯卧撑，下蹲，Tricep俯卧在椅子上，木板，高位膝盖就位，滑刺，俯卧撑和旋转，侧板（每轮交替），交替式俯卧撑板，扩胸器，菱形俯卧撑，潜水轰炸机俯卧撑，对接踢球，卧式三头肌举重，单臂侧俯卧撑，高架手臂拍打，高架俯卧撑，动力圈，猫h向上和旋转，T俯卧撑，反向木板，蜘蛛侠俯卧撑，T提升，三叉戟俯卧撑，墙壁俯卧撑，宽臂俯卧撑，Burbures]}，标题=你好锻炼，类别=力量，长度= 1，目标=此锻炼可以在电话中完成！}}
03-28 08：52：53.967 23584-23584 / com.android.sam I / System.out：{-KDnfjROKeFAL9wccsxY = {weeks = {week1 = [高膝盖，下蹲，肺，钻石俯卧撑，卧式三头肌训练器]] }，标题=下午HitT，类别=流动性，长度= 1，目标=下午体重锻炼}，-KDps90Dn6XtJc6Co00b = {weeks = {week1 = [Diamond Pushups，Jackknives，Plyo Lunges，Plyo Squats，单腿木板（每人备用）圆形），Plyo刺，俯卧撑和旋转，配重侧板（每轮备用），交替俯卧撑板，扩胸器，菱形俯卧撑，潜水轰炸俯卧撑，单臂俯卧撑，高架俯卧撑，俯卧撑向上和旋转，T俯卧撑，蜘蛛侠俯卧撑，宽臂俯卧撑，Burpee俯卧撑]}，标题=标题，类别=强度，长度= 1，目标=目标}}
程式库
public class Program {
private String title;
private String goal;
private String category;
private int length;
HashMap<String, ArrayList<String>> weeks;
/**
* Required public constructor
*/
public Program() {
}
public Program(String title, String goal, String category, int length, HashMap<String, ArrayList<String>> weeks) {
this.title = title;
this.goal = goal;
this.category = category;
this.length = length;
this.weeks = weeks;
}
public String getTitle() {
return title;
}
public String getGoal() {
return goal;
}
public String getCategory() {
return category;
}
public int getLength() {
return length;
}
public HashMap<String, ArrayList<String>> getweeks() {
return weeks;
}
}
最佳答案
正如@ReazMurshed所说的，您快到了。但是您无法在树中迭代一个级别。似乎ref指向JSON中的subscriptions节点。在此之下，您拥有用户，然后有了推送ID。因此，您需要执行一个双循环：
ref.addListenerForSingleValueEvent(new ValueEventListener) {
public void onDataChange(DataSnapshot snapshot) {
if (dataSnapshot.exists()) {
for (DataSnapshot userSnapshot : snapshot.getChildren()) {
for (DataSnapshot programSnapshot : userSnapshot.getChildren()) {
Program program = programSnapshot.getValue(Program.class);
}
}
}
public void onCancelled(FirebaseError firebaseError) {
}
});