将stackoverflow错误写入实时数据库答案

【问题标题】：Getting stackoverflow error writing to realtime database将stackoverflow错误写入实时数据库
【发布时间】：2018-03-20 15:45:32
【问题描述】：

我正在尝试将一个对象上传到 Firebase 数据库，但是当我这样做时，我得到了一个 stackoverflowerror。我看到很多人遇到此错误，但他们的解决方案在我的情况下不起作用。我唯一能做到的就是写一个字符串变量。

我试图：检查我的所有对象变量是否被 Firebase 序列化允许

这是代码：

对象

package chtecnologies.lola.entities;

import com.google.gson.Gson;
import com.google.gson.JsonObject;

import java.io.Serializable;

public class Pet {

private String id;
private String name;
private String breed;
private String type;
private String pictures;
private String description;
private String location;
private String locality;
private String gender;
private String age;
private String userid;

public Pet(String id, String name, String breed, String type, String description,
           String pictures, String location, String locality, String gender,
           String age, String userid) {

    this.id = id;
    this.name = name;
    this.breed = breed;
    this.type = type;
    this.description = description;
    this.pictures = pictures;
    this.location = location;
    this.locality = locality;
    this.gender = gender;
    this.age = age;
    this.userid = userid;
}

public Pet(String breed, String type, String pictures, String description, String location, String locality, String gender, String age, String userid) {
    /** CONSTRUCTOR FOR ADOPTABLE PET**/
    this.breed = breed;
    this.type = type;
    this.pictures = pictures;
    this.description = description;
    this.location = location;
    this.locality = locality;
    this.gender = gender;
    this.age = age;
    this.userid = userid;
}

public Pet(String name, String breed, String type, String pictures, String description, String location, String locality, String userid) {
/** CONSTRUCTOR FOR LOST PET**/

    this.name = name;
    this.breed = breed;
    this.type = type;
    this.pictures = pictures;
    this.description = description;
    this.location = location;
    this.locality = locality;
    this.userid = userid;
}

public String getId() {
    return id;
}

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

public String getBreed() {
    return breed;
}

public void setBreed(String breed) {
    this.breed = breed;
}

public String getType() {
    return type;
}

public void setType(String type) {
    this.type = type;
}

public String getDescription() {
    return description;
}

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

public String getPictures() {
    return pictures;
}

public void setPictures(String pictures) {
    this.pictures = pictures;
}

public String getLocation() {
    return location;
}

public void setLocation(String location) {
    this.location = location;
}

public String getUserid() {
    return userid;
}

public void setUserid(String userid) {
    this.userid = userid;
}

public String getLocality(){ return locality; }

public void setLocality(String locality){
    this.locality = locality;
}

public String getName() {
    return name;
}

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

public String getAge() {
    return age;
}

public void setAge(String age) {
    this.age = age;
}

public String getGender() {
    return gender;
}

public void setGender(String gender) {
    this.gender = gender;
}

public Pet getPet(){
    return this;
}


@Override
public String toString() {
    return "Pet{" +
            "id='" + id + '\'' +
            ", name='" + name + '\'' +
            ", breed='" + breed + '\'' +
            ", type='" + type + '\'' +
            ", pictures=" + pictures +
            ", description='" + description + '\'' +
            ", location='" + location + '\'' +
            ", locality='" + locality + '\'' +
            ", gender='" + gender + '\'' +
            ", age='" + age + '\'' +
            ", userid='" + userid + '\'' +
            '}';
}
}

写入数据库的方法：

@Override
public void postPet(Pet pet) {
    FirebaseDatabase database = FirebaseDatabase.getInstance();
    DatabaseReference ref = database.getReference();

 //        TODO: Next line throwing stackoverflow error
    ref.push().setValue(pet);

    Intent intent = new Intent(mContext, MainActivity.class);
    mContext.startActivity(intent);
 }

Logcat

FATAL EXCEPTION: main
                                                                Process: chtecnologies.lola, PID: 11761
                                                                java.lang.StackOverflowError: stack size 8MB
                                                                    at java.lang.reflect.Method.invoke(Native Method)
                                                                    at com.google.android.gms.internal.zzelx.zzcb(Unknown Source:58)
                                                                    at com.google.android.gms.internal.zzelw.zzbx(Unknown Source:237)
                                                                    at com.google.android.gms.internal.zzelw.zzca(Unknown Source:0)
                                                                    at com.google.android.gms.internal.zzelx.zzcb(Unknown Source:120)
                                                                    at com.google.android.gms.internal.zzelw.zzbx(Unknown Source:237)
                                                                    at com.google.android.gms.internal.zzelw.zzca(Unknown Source:0)
                                                                    at com.google.android.gms.internal.zzelx.zzcb(Unknown Source:120)
                                                                    at com.google.android.gms.internal.zzelw.zzbx(Unknown Source:237)
                                                                    at com.google.android.gms.internal.zzelw.zzca(Unknown Source:0)
                                                                    at com.google.android.gms.internal.zzelx.zzcb(Unknown Source:120)
                                                                    at com.google.android.gms.internal.zzelw.zzbx(Unknown Source:237)
                                                                    at com.google.android.gms.internal.zzelw.zzca(Unknown Source:0)
                                                                    at com.google.android.gms.internal.zzelx.zzcb(Unknown Source:120)
                                                                    at com.google.android.gms.internal.zzelw.zzbx(Unknown Source:237)
                                                                    at com.google.android.gms.internal.zzelw.zzca(Unknown Source:0)
                                                                    at com.google.android.gms.internal.zzelx.zzcb(Unknown Source:120)
                                                                    at com.google.android.gms.internal.zzelw.zzbx(Unknown Source:237)
                                                                    at com.google.android.gms.internal.zzelw.zzca(Unknown Source:0)
                                                                    at com.google.android.gms.internal.zzelx.zzcb(Unknown Source:120)
                                                                    at com.google.android.gms.internal.zzelw.zzbx(Unknown Source:237)
                                                                    at com.google.android.gms.internal.zzelw.zzca(Unknown Source:0)
                                                                    at com.google.android.gms.internal.zzelx.zzcb(Unknown Source:120)
                                                                    at com.google.android.gms.internal.zzelw.zzbx(Unknown Source:237)
                                                                    at com.google.android.gms.internal.zzelw.zzca(Unknown Source:0)
                                                                    at com.google.android.gms.internal.zzelx.zzcb(Unknown Source:120)
                                                                    at com.google.android.gms.internal.zzelw.zzbx(Unknown Source:237)
                                                                    at com.google.android.gms.internal.zzelw.zzca(Unknown Source:0)
                                                                    at com.google.android.gms.internal.zzelx.zzcb(Unknown Source:120)
                                                                    at com.google.android.gms.internal.zzelw.zzbx(Unknown Source:237)
                                                                    at com.google.android.gms.internal.zzelw.zzca(Unknown Source:0)
                                                                    at com.google.android.gms.internal.zzelx.zzcb(Unknown Source:120)
                                                                    at 
                                                                       at com.google.android.gms.internal.zzelw.zzbx(Unknown Source:237)
                                                                    at com.google.android.gms.internal.zzelw.zzca(Unknown Source:0)
                                                                    at    com.google.android.gms.internal.zzelx.zzcb(Unknown Source:120)
03-20 12:28:55.008 11761-11761/chtecnologies.lola E/AndroidRuntime:        at       com.google.android.gms.internal.zzelw.zzbx(Unknown Source:237)
                                                                    at com.google.android.gms.internal.zzelw.zzca(Unknown Source:0)
                                                                    at com.google.android.gms.internal.zzelx.zzcb(Unknown Source:120)
                                                                    at com.google.android.gms.internal.zzelw.zzbx(Unknown Source:237)
                                                                    at com.google.android.gms.internal.zzelw.zzca(Unknown Source:0)
                                                                    at com.google.android.gms.internal.zzelx.zzcb(Unknown Source:120)
                                                                    at com.google.android.gms.internal.zzelw.zzbx(Unknown Source:237)
                                                                    at com.google.android.gms.internal.zzelw.zzca(Unknown Source:0)
                                                                    at com.google.android.gms.internal.zzelx.zzcb(Unknown Source:120)
                                                                    at com.google.android.gms.internal.zzelw.zzbx(Unknown Source:237)
                                                                    at com.google.android.gms.internal.zzelw.zzca(Unknown Source:0)
                                                                    at com.google.android.gms.internal.zzelx.zzcb(Unknown Source:120)
                                                                    at com.google.android.gms.internal.zzelw.zzbx(Unknown Source:237)
                                                                    at com.google.android.gms.internal.zzelw.zzca(Unknown Source:0)
                                                                    at com.google.android.gms.internal.zzelx.zzcb(Unknown Source:120)
                                                                    at com.google.android.gms.internal.zzelw.zzbx(Unknown Source:237)
                                                                    at com.google.android.gms.internal.zzelw.zzca(Unknown Source:0)
                                                                    at com.google.android.gms.internal.zzelx.zzcb(Unknown Source:120)
                                                                    at com.google.android.gms.internal.zzelw.zzbx(Unknown Source:237)
                                                                    at com.google.android.gms.internal.zzelw.zzca(Unknown Source:0)
                                                                    at com.google.android.gms.internal.zzelx.zzcb(Unknown Source:120)
                                                                    at com.google.android.gms.internal.zzelw.zzbx(Unknown Source:237)
                                                                    at com.google.android.gms.internal.zzelw.zzca(Unknown Source:0)
                                                                    at com.google.android.gms.internal.zzelx.zzcb(Unknown Source:120)
                                                                    at com.google.android.gms.internal.zzelw.zzbx(Unknown Source:237)
                                                                    at com.google.android.gms.internal.zzelw.zzca(Unknown Source:0)
                                                                    at com.google.android.gms.internal.zzelx.zzcb(Unknown Source:120)
                                                                    at com.google.android.gms.internal.zzelw.zzbx(Unknown Source:237)
                                                                    at com.google.android.gms.internal.zzelw.zzca(Unknown Source:0)
                                                                    at com.google.android.gms.internal.zzelx.zzcb(Unknown Source:120)
                                                                    at com.google.android.gms.internal.zzelw.zzbx(Unknown Source:237)
                                                                    at com.google.android.gms.internal.zzelw.zzca(Unknown Source:0)
                                                                    at com.google.android.gms.internal.zzelx.zzcb(Unknown Source:120)
                                                                    at com.google.android.gms.internal.zzelw.zzbx(Unknown Source:237)
                                                                    at com.google.android.gms.internal.zzelw.zzca(Unknown Source:0)
                                                                    at com.google.android.gms.internal.zzelx.zzcb(Unknown Source:120)
                                                                    at com.google.android.gms.internal.zzelw.zzbx(Unknown Source:237)
                                                                    at com.google.android.gms.internal.zzelw.zzca(Unknown Source:0)
                                                                    at com.google.android.gms.internal.zzelx.zzcb(Unknown Source:120)
                                                                    at com.google.android.gms.internal.zzelw.zzbx(Unknown Source:237)
                                                                    at com.google.android.gms.internal.zzelw.zzca(Unknown Source:0)
                                                                    at com.google.android.gms.internal.zzelx.zzcb(Unknown Source:120)
                                                                    at com.google.android.gms.internal.zzelw.zzbx(Unknown Source:237)
                                                                    at com.google.android.gms.internal.zzelw.zzbw(Unknown Source:0)
                                                                    at com.google.firebase.database.DatabaseReference.zza(Unknown Source:10)
                                                                    at com.google.firebase.database.DatabaseReference.setValue(Unknown Source:7)
                                                                    at chtecnologies.lola.ui.activities.LoadPresenter.postPet(LoadPresenter.java:144)
                                                                    at chtecnologies.lola.ui.activities.LoadPresenter.checkFieldsLost(LoadPresenter.java:132)
                                                                    at chtecnologies.lola.ui.activities.PostLostActivity$3.onClick(PostLostActivity.java:101)
                                                                    at android.view.View.performClick(View.java:6256)
                                                                    at android.view.View$PerformClick.run(View.java:24701)
                                                                    at android.os.Handler.handleCallback(Handler.java:789)
                                                                    at android.os.Handler.dispatchMessage(Handler.java:98)
                                                                    at android.os.Looper.loop(Looper.java:164)
                                                                    at android.app.ActivityThread.main(ActivityThread.java:6541)
                                                                    at java.lang.reflect.Method.invoke(Native Method)
                                                                    at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
                                                                    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)

我删除了一些相同的行，因为我超出了字符数

我是 Firebase 的新手，我试图将我的实际存储数据库更改为 Firebase，但我无法让它工作。我阅读了文档，但看不到我在做任何不允许的事情。我希望你能帮我解决这个问题。谢谢！

【问题讨论】：

如果您看到崩溃，请将整个堆栈跟踪复制到您的问题中。
我更新了帖子
您的 'getPet' 正在导致递归 firebase 推送。 Firebase 使用反射来查找所有“getter”，在本例中是查找“getPet”，这显然是对自身的引用。

标签： android firebase google-cloud-platform

【解决方案1】：

您需要在 Pet 类中添加无参数构造函数，因为 Firebase 需要该构造函数。

public Pet() {}

并删除这些行：

public Pet getPet(){
    return this;
}

当 Firebase 实时数据库 SDK 反序列化来自数据库的对象时，它要求所有正在使用的对象都必须具有 public no-argument constructor，以便它可以使用它来实例化对象。对象中的字段通过使用公共 setter 方法或直接访问公共成员来设置。

如果您的宠物对象没有public no-arg constructor，SDK 并不真正知道如何创建它的实例。所以必须要有。

【讨论】：

我尝试实现 Serializable 类，但没有成功。但我没有空的构造函数。我会修复它，我会回复你。谢谢
好的，让我知道。不要忘记删除getPet() 方法。它必须是构造函数而不是方法。
成功了！导致错误的方法是getPet()，我还添加了空构造函数。但是我没有实现 Serializable 类并且它正在工作，您是否建议仍然实现它？
很高兴它成功了。不，此时您的所有字段都是可序列化的，因为是字符串。更新了我的答案。