com.google.firebase.database.DatabaseException:Can'；t将java.util.ArrayList类型的对象转换为

我收到一个Firebase DatabaseException“无法将java.util.ArrayList类型的对象转换为com.example.FirebasedEleme.Title类型” 当我单击该流程时，应用程序崩溃并显示错误。是否知道错误以及如何修复错误

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.ashina.hotelsclient, PID: 15925
    com.google.firebase.database.DatabaseException: Can't convert object of type java.util.ArrayList to type com.ashina.hotelsclient.Model.FoodModel
        at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.convertBean(CustomClassMapper.java:436)
        at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.deserializeToClass(CustomClassMapper.java:232)
        at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.convertToCustomClass(CustomClassMapper.java:80)
        at com.google.firebase.database.DataSnapshot.getValue(DataSnapshot.java:203)
        at com.ashina.hotelsclient.HomeActivity$4$1.onDataChange(HomeActivity.java:276)
        at com.google.firebase.database.Query$1.onDataChange(Query.java:179)
        at com.google.firebase.database.core.ValueEventRegistration.fireEvent(ValueEventRegistration.java:75)
        at com.google.firebase.database.core.view.DataEvent.fire(DataEvent.java:63)
        at com.google.firebase.database.core.view.EventRaiser$1.run(EventRaiser.java:55)
        at android.os.Handler.handleCallback(Handler.java:883)
        at android.os.Handler.dispatchMessage(Handler.java:100)
        at android.os.Looper.loop(Looper.java:237)
        at android.app.ActivityThread.main(ActivityThread.java:7948)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1075)

这是我的家庭活动.java

@Subscribe(sticky = true,threadMode = ThreadMode.MAIN)
public void onPopularItemClick(PopularCategoryClick event)
{
    if (event.getPopularCategoryModel() != null)
    {
        dialog.show();

        FirebaseDatabase.getInstance()
                .getReference("Category")
                .child(event.getPopularCategoryModel().getMenu_id())
                .addListenerForSingleValueEvent(new ValueEventListener() {
                    @Override
                    public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                        if (dataSnapshot.exists())
                        {
                            Common.categorySelected = dataSnapshot.getValue(CategoryModel.class);

                            //load food
                            FirebaseDatabase.getInstance()
                                    .getReference("Category")
                                    .child(event.getPopularCategoryModel().getMenu_id())
                                    .child("foods")
                                    .orderByChild("id")
                                    .equalTo(event.getPopularCategoryModel().getFood_id())
                                    .limitToLast(1)
                                    .addListenerForSingleValueEvent(new ValueEventListener() {
                                        @Override
                                        public void onDataChange(@NonNull DataSnapshot dataSnapshot1) {
                                            if (dataSnapshot.exists())
                                            {
                                                for (DataSnapshot itemSnapShot:dataSnapshot.getChildren())
                                                {
                                                    Common.selectedFood = itemSnapShot.getValue(FoodModel.class);
                                                }

                                                navController.navigate(R.id.nav_food_detail);
                                            }
                                            else
                                            {

                                                Toast.makeText(HomeActivity.this, "Item doesn't exists", Toast.LENGTH_SHORT).show();

                                            }
                                            dialog.dismiss();
                                        }

                                        @Override
                                        public void onCancelled(@NonNull DatabaseError databaseError) {
                                            dialog.dismiss();
                                            Toast.makeText(HomeActivity.this, ""+databaseError.getMessage(), Toast.LENGTH_SHORT).show();
                                        }
                                    });

                        }
                        else
                        {
                            dialog.dismiss();
                            Toast.makeText(HomeActivity.this, "Item doesn't exists!", Toast.LENGTH_SHORT).show();
                        }
                    }

public class Common {
    public static final String USER_REFERENCES = "Users";
    public static final String POPULAR_CATEGORY_REF = "MostPopular" ;
    public static final String BEST_DEALS_REF = "BestDeals";
    public static final int DEFAULT_COLUMN_COUNT = 0;
    public static final int FULL_WIDTH_COLUMN = 1;
    public static final String CATEGORY_REF = "Category";
    public static final String COMMENT_REF = "Comments";
    public static UserModel currentUser;
    public static CategoryModel categorySelected;
    public static  FoodModel selectedFood;

    public static String formatPrice(double price) {
        if (price != 0)
        {
            DecimalFormat df = new DecimalFormat("#,##0.00");
            df.setRoundingMode(RoundingMode.UP);
            String finalPrice = new StringBuilder(df.format(price)).toString();
            return finalPrice.replace(".",",");
        }
        else
            return "0,00";
    }

    public static Double calculateExtraPrice(SizeModel userSelectedSize, List<AddonModel> userSelectedAddon) {
        Double result = 0.0;
        if (userSelectedSize == null && userSelectedAddon == null)
            return 0.0;
        else if (userSelectedSize == null)
        {
            //if user selected addon != null we need sum price
            for(AddonModel addonModel : userSelectedAddon)
                result+=addonModel.getPrice();
            return result;
        }
        else if (userSelectedAddon == null)
        {
            return userSelectedSize.getPrice()*1.0;
        }
        else
        {
            //if both size and addon is selected
            result = userSelectedSize.getPrice()*1.0;
            for(AddonModel addonModel : userSelectedAddon)
                result+=addonModel.getPrice();
            return result;
        }

    }

    public static void setSpanString(String welcome, String name, TextView textView) {
        SpannableStringBuilder builder = new SpannableStringBuilder();
        builder.append(welcome);
        SpannableString spannableString = new SpannableString(name);
        StyleSpan boldSpan = new StyleSpan(Typeface.BOLD);
        spannableString.setSpan(boldSpan,0,name.length(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
        builder.append(spannableString);
        textView.setText(builder,TextView.BufferType.SPANNABLE);
    }
}

public class FoodModel {
    private String key;
    private String name,image,id,description;
    private Long price;
    private List<AddonModel> addon;
    private List<SizeModel> size;
    private Double ratingValue;
    private Long ratingCount;

    //for cart
    private List<AddonModel> userSelectedAddon;
    private SizeModel userSelectedSize;

    public FoodModel() {
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getImage() {
        return image;
    }

    public void setImage(String image) {
        this.image = image;
    }

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public Long getPrice() {
        return price;
    }

    public void setPrice(Long price) {
        this.price = price;
    }

    public List<AddonModel> getAddon() {
        return addon;
    }

    public void setAddon(List<AddonModel> addon) {
        this.addon = addon;
    }

    public List<SizeModel> getSize() {
        return size;
    }

    public void setSize(List<SizeModel> size) {
        this.size = size;
    }

    public String getKey() {
        return key;
    }

    public void setKey(String key) {
        this.key = key;
    }

    public Double getRatingValue() {
        return ratingValue;
    }

    public void setRatingValue(Double ratingValue) {
        this.ratingValue = ratingValue;
    }

    public Long getRatingCount() {
        return ratingCount;
    }

    public void setRatingCount(Long ratingCount) {
        this.ratingCount = ratingCount;
    }

    public List<AddonModel> getUserSelectedAddon() {
        return userSelectedAddon;
    }

    public void setUserSelectedAddon(List<AddonModel> userSelectedAddon) {
        this.userSelectedAddon = userSelectedAddon;
    }

    public SizeModel getUserSelectedSize() {
        return userSelectedSize;
    }

    public void setUserSelectedSize(SizeModel userSelectedSize) {
        this.userSelectedSize = userSelectedSize;
    }
}

common.java

@Subscribe(sticky = true,threadMode = ThreadMode.MAIN)
public void onPopularItemClick(PopularCategoryClick event)
{
    if (event.getPopularCategoryModel() != null)
    {
        dialog.show();

        FirebaseDatabase.getInstance()
                .getReference("Category")
                .child(event.getPopularCategoryModel().getMenu_id())
                .addListenerForSingleValueEvent(new ValueEventListener() {
                    @Override
                    public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                        if (dataSnapshot.exists())
                        {
                            Common.categorySelected = dataSnapshot.getValue(CategoryModel.class);

                            //load food
                            FirebaseDatabase.getInstance()
                                    .getReference("Category")
                                    .child(event.getPopularCategoryModel().getMenu_id())
                                    .child("foods")
                                    .orderByChild("id")
                                    .equalTo(event.getPopularCategoryModel().getFood_id())
                                    .limitToLast(1)
                                    .addListenerForSingleValueEvent(new ValueEventListener() {
                                        @Override
                                        public void onDataChange(@NonNull DataSnapshot dataSnapshot1) {
                                            if (dataSnapshot.exists())
                                            {
                                                for (DataSnapshot itemSnapShot:dataSnapshot.getChildren())
                                                {
                                                    Common.selectedFood = itemSnapShot.getValue(FoodModel.class);
                                                }

                                                navController.navigate(R.id.nav_food_detail);
                                            }
                                            else
                                            {

                                                Toast.makeText(HomeActivity.this, "Item doesn't exists", Toast.LENGTH_SHORT).show();

                                            }
                                            dialog.dismiss();
                                        }

                                        @Override
                                        public void onCancelled(@NonNull DatabaseError databaseError) {
                                            dialog.dismiss();
                                            Toast.makeText(HomeActivity.this, ""+databaseError.getMessage(), Toast.LENGTH_SHORT).show();
                                        }
                                    });

                        }
                        else
                        {
                            dialog.dismiss();
                            Toast.makeText(HomeActivity.this, "Item doesn't exists!", Toast.LENGTH_SHORT).show();
                        }
                    }

public class Common {
    public static final String USER_REFERENCES = "Users";
    public static final String POPULAR_CATEGORY_REF = "MostPopular" ;
    public static final String BEST_DEALS_REF = "BestDeals";
    public static final int DEFAULT_COLUMN_COUNT = 0;
    public static final int FULL_WIDTH_COLUMN = 1;
    public static final String CATEGORY_REF = "Category";
    public static final String COMMENT_REF = "Comments";
    public static UserModel currentUser;
    public static CategoryModel categorySelected;
    public static  FoodModel selectedFood;

    public static String formatPrice(double price) {
        if (price != 0)
        {
            DecimalFormat df = new DecimalFormat("#,##0.00");
            df.setRoundingMode(RoundingMode.UP);
            String finalPrice = new StringBuilder(df.format(price)).toString();
            return finalPrice.replace(".",",");
        }
        else
            return "0,00";
    }

    public static Double calculateExtraPrice(SizeModel userSelectedSize, List<AddonModel> userSelectedAddon) {
        Double result = 0.0;
        if (userSelectedSize == null && userSelectedAddon == null)
            return 0.0;
        else if (userSelectedSize == null)
        {
            //if user selected addon != null we need sum price
            for(AddonModel addonModel : userSelectedAddon)
                result+=addonModel.getPrice();
            return result;
        }
        else if (userSelectedAddon == null)
        {
            return userSelectedSize.getPrice()*1.0;
        }
        else
        {
            //if both size and addon is selected
            result = userSelectedSize.getPrice()*1.0;
            for(AddonModel addonModel : userSelectedAddon)
                result+=addonModel.getPrice();
            return result;
        }

    }

    public static void setSpanString(String welcome, String name, TextView textView) {
        SpannableStringBuilder builder = new SpannableStringBuilder();
        builder.append(welcome);
        SpannableString spannableString = new SpannableString(name);
        StyleSpan boldSpan = new StyleSpan(Typeface.BOLD);
        spannableString.setSpan(boldSpan,0,name.length(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
        builder.append(spannableString);
        textView.setText(builder,TextView.BufferType.SPANNABLE);
    }
}

public class FoodModel {
    private String key;
    private String name,image,id,description;
    private Long price;
    private List<AddonModel> addon;
    private List<SizeModel> size;
    private Double ratingValue;
    private Long ratingCount;

    //for cart
    private List<AddonModel> userSelectedAddon;
    private SizeModel userSelectedSize;

    public FoodModel() {
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getImage() {
        return image;
    }

    public void setImage(String image) {
        this.image = image;
    }

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public Long getPrice() {
        return price;
    }

    public void setPrice(Long price) {
        this.price = price;
    }

    public List<AddonModel> getAddon() {
        return addon;
    }

    public void setAddon(List<AddonModel> addon) {
        this.addon = addon;
    }

    public List<SizeModel> getSize() {
        return size;
    }

    public void setSize(List<SizeModel> size) {
        this.size = size;
    }

    public String getKey() {
        return key;
    }

    public void setKey(String key) {
        this.key = key;
    }

    public Double getRatingValue() {
        return ratingValue;
    }

    public void setRatingValue(Double ratingValue) {
        this.ratingValue = ratingValue;
    }

    public Long getRatingCount() {
        return ratingCount;
    }

    public void setRatingCount(Long ratingCount) {
        this.ratingCount = ratingCount;
    }

    public List<AddonModel> getUserSelectedAddon() {
        return userSelectedAddon;
    }

    public void setUserSelectedAddon(List<AddonModel> userSelectedAddon) {
        this.userSelectedAddon = userSelectedAddon;
    }

    public SizeModel getUserSelectedSize() {
        return userSelectedSize;
    }

    public void setUserSelectedSize(SizeModel userSelectedSize) {
        this.userSelectedSize = userSelectedSize;
    }
}

公共类公共类{
公共静态最终字符串USER\u REFERENCES=“Users”；
公共静态最终字符串POPULAR\u CATEGORY\u REF=“MostPopular”；
公共静态最终字符串BEST\u DEALS\u REF=“BestDeals”；
公共静态final int DEFAULT_COLUMN_COUNT=0；
公共静态最终整型整列宽度=1；
公共静态最终字符串CATEGORY\u REF=“CATEGORY”；
公共静态最终字符串注释\u REF=“Comments”；
公共静态用户模型currentUser；
已选择公共静态类别模型类别；
公共静态食品模型选择食品；
公共静态字符串格式价格（双倍价格）{
如果（价格！=0）
{
DecimalFormat df=新的DecimalFormat（“#，##0.00”）；
df.setRoundingMode（RoundingMode.UP）；
String finalPrice=newstringbuilder（df.format（price））.toString（）；
返回最终价格。替换（“.”，“，”）；
}
其他的
返回“0,00”；
}
公共静态双计算额外价格（SizeModel userSelectedSize，List UserSelectedAddress）{
双结果=0.0；
if（userSelectedSize==null&&userselectedddon==null）
返回0.0；
else if（userSelectedSize==null）
{
//如果用户选择的插件！=null，我们需要总价
for（AddonModel AddonModel:userSelectedAddon）
结果+=addonModel.getPrice（）；
返回结果；
}
else if（UserSelectedAddress==null）
{
返回userSelectedSize.getPrice（）*1.0；
}
其他的
{
//如果同时选择了大小和加载项
结果=userSelectedSize.getPrice（）*1.0；
for（AddonModel AddonModel:userSelectedAddon）
结果+=addonModel.getPrice（）；
返回结果；
}
}
公共静态void setPanString（字符串欢迎、字符串名称、TextView TextView）{
SpannableStringBuilder=新的SpannableStringBuilder（）；
附加（欢迎）；
SpannableString SpannableString=新的SpannableString（名称）；
StyleSpan boldSpan=新的StyleSpan（Typeface.BOLD）；
spannableString.setSpan（粗体SPAN，0，name.length（），SPAN.SPAN_EXCLUSIVE_EXCLUSIVE）；
builder.append（spannableString）；
setText（生成器，textView.BufferType.Spanable）；
}
}

foodmodel.java

@Subscribe(sticky = true,threadMode = ThreadMode.MAIN)
public void onPopularItemClick(PopularCategoryClick event)
{
    if (event.getPopularCategoryModel() != null)
    {
        dialog.show();

        FirebaseDatabase.getInstance()
                .getReference("Category")
                .child(event.getPopularCategoryModel().getMenu_id())
                .addListenerForSingleValueEvent(new ValueEventListener() {
                    @Override
                    public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                        if (dataSnapshot.exists())
                        {
                            Common.categorySelected = dataSnapshot.getValue(CategoryModel.class);

                            //load food
                            FirebaseDatabase.getInstance()
                                    .getReference("Category")
                                    .child(event.getPopularCategoryModel().getMenu_id())
                                    .child("foods")
                                    .orderByChild("id")
                                    .equalTo(event.getPopularCategoryModel().getFood_id())
                                    .limitToLast(1)
                                    .addListenerForSingleValueEvent(new ValueEventListener() {
                                        @Override
                                        public void onDataChange(@NonNull DataSnapshot dataSnapshot1) {
                                            if (dataSnapshot.exists())
                                            {
                                                for (DataSnapshot itemSnapShot:dataSnapshot.getChildren())
                                                {
                                                    Common.selectedFood = itemSnapShot.getValue(FoodModel.class);
                                                }

                                                navController.navigate(R.id.nav_food_detail);
                                            }
                                            else
                                            {

                                                Toast.makeText(HomeActivity.this, "Item doesn't exists", Toast.LENGTH_SHORT).show();

                                            }
                                            dialog.dismiss();
                                        }

                                        @Override
                                        public void onCancelled(@NonNull DatabaseError databaseError) {
                                            dialog.dismiss();
                                            Toast.makeText(HomeActivity.this, ""+databaseError.getMessage(), Toast.LENGTH_SHORT).show();
                                        }
                                    });

                        }
                        else
                        {
                            dialog.dismiss();
                            Toast.makeText(HomeActivity.this, "Item doesn't exists!", Toast.LENGTH_SHORT).show();
                        }
                    }

public class Common {
    public static final String USER_REFERENCES = "Users";
    public static final String POPULAR_CATEGORY_REF = "MostPopular" ;
    public static final String BEST_DEALS_REF = "BestDeals";
    public static final int DEFAULT_COLUMN_COUNT = 0;
    public static final int FULL_WIDTH_COLUMN = 1;
    public static final String CATEGORY_REF = "Category";
    public static final String COMMENT_REF = "Comments";
    public static UserModel currentUser;
    public static CategoryModel categorySelected;
    public static  FoodModel selectedFood;

    public static String formatPrice(double price) {
        if (price != 0)
        {
            DecimalFormat df = new DecimalFormat("#,##0.00");
            df.setRoundingMode(RoundingMode.UP);
            String finalPrice = new StringBuilder(df.format(price)).toString();
            return finalPrice.replace(".",",");
        }
        else
            return "0,00";
    }

    public static Double calculateExtraPrice(SizeModel userSelectedSize, List<AddonModel> userSelectedAddon) {
        Double result = 0.0;
        if (userSelectedSize == null && userSelectedAddon == null)
            return 0.0;
        else if (userSelectedSize == null)
        {
            //if user selected addon != null we need sum price
            for(AddonModel addonModel : userSelectedAddon)
                result+=addonModel.getPrice();
            return result;
        }
        else if (userSelectedAddon == null)
        {
            return userSelectedSize.getPrice()*1.0;
        }
        else
        {
            //if both size and addon is selected
            result = userSelectedSize.getPrice()*1.0;
            for(AddonModel addonModel : userSelectedAddon)
                result+=addonModel.getPrice();
            return result;
        }

    }

    public static void setSpanString(String welcome, String name, TextView textView) {
        SpannableStringBuilder builder = new SpannableStringBuilder();
        builder.append(welcome);
        SpannableString spannableString = new SpannableString(name);
        StyleSpan boldSpan = new StyleSpan(Typeface.BOLD);
        spannableString.setSpan(boldSpan,0,name.length(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
        builder.append(spannableString);
        textView.setText(builder,TextView.BufferType.SPANNABLE);
    }
}

public class FoodModel {
    private String key;
    private String name,image,id,description;
    private Long price;
    private List<AddonModel> addon;
    private List<SizeModel> size;
    private Double ratingValue;
    private Long ratingCount;

    //for cart
    private List<AddonModel> userSelectedAddon;
    private SizeModel userSelectedSize;

    public FoodModel() {
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getImage() {
        return image;
    }

    public void setImage(String image) {
        this.image = image;
    }

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public Long getPrice() {
        return price;
    }

    public void setPrice(Long price) {
        this.price = price;
    }

    public List<AddonModel> getAddon() {
        return addon;
    }

    public void setAddon(List<AddonModel> addon) {
        this.addon = addon;
    }

    public List<SizeModel> getSize() {
        return size;
    }

    public void setSize(List<SizeModel> size) {
        this.size = size;
    }

    public String getKey() {
        return key;
    }

    public void setKey(String key) {
        this.key = key;
    }

    public Double getRatingValue() {
        return ratingValue;
    }

    public void setRatingValue(Double ratingValue) {
        this.ratingValue = ratingValue;
    }

    public Long getRatingCount() {
        return ratingCount;
    }

    public void setRatingCount(Long ratingCount) {
        this.ratingCount = ratingCount;
    }

    public List<AddonModel> getUserSelectedAddon() {
        return userSelectedAddon;
    }

    public void setUserSelectedAddon(List<AddonModel> userSelectedAddon) {
        this.userSelectedAddon = userSelectedAddon;
    }

    public SizeModel getUserSelectedSize() {
        return userSelectedSize;
    }

    public void setUserSelectedSize(SizeModel userSelectedSize) {
        this.userSelectedSize = userSelectedSize;
    }
}

公共类食品模型{
私钥；
私有字符串名称、图像、id、描述；
私人多头价格；
私有列表插件；
私有列表大小；
私人双重价值；
私人长期评级计数；
//手推车
私有列表用户选择的DDON；
私有大小模型userSelectedSize；
公共食品模型（）{
}
公共字符串getName（）{
返回名称；
}
公共void集合名（字符串名）{
this.name=名称；
}
公共字符串getImage（）{
返回图像；
}
公共void setImage（字符串图像）{
这个图像=图像；
}
公共字符串getId（）{
返回id；
}
公共无效集合id（字符串id）{
this.id=id；
}
公共字符串getDescription（）{
返回说明；
}
公共void集合描述（字符串描述）{
this.description=描述；
}
公共长期价格（）{
退货价格；
}
公共定价（长期价格）{
这个价格=价格；
}
公共列表getAddon（）{
返回插件；
}
公共无效设置加载项（列表加载项）{
this.addon=addon；
}
公共列表getSize（）{
返回大小；
}
公共无效设置大小（列表大小）{
这个。大小=大小；
}
公共字符串getKey（）{
返回键；
}
公共无效设置键（字符串键）{
this.key=key；
}
公共双getRatingValue（）{
回报率值；
}
公共无效设置值（双额定值）{
this.ratingValue=ratingValue；
}
公共长getRatingCount（）{
收益率计数；
}
公共无效设置计数（长计数）{
this.ratingCount=ratingCount；
}
公共列表GetUserSelectedAddress（）{
返回用户选择的地址；
}
public void setUserSelectedAddress（列出UserSelectedAddress）{
this.userSelectedAddon=userSelectedAddon；
}
公共大小模型getUserSelectedSize（）{
返回userSelectedSize；
}
public void setUserSelectedSize（SizeModel userSelectedSize）{
this.userSelectedSize=userSelectedSize；
}
}