com.google.firebase.database.DatabaseException：无法使用类解析节点

Question

我尝试通过Snackbar提供的操作撤消删除操作。

以下是删除操作：

dbRef.child(footballer.getFullName()).removeValue();

当我通过下面添加的命令调用撤消操作时，获取com.google.firebase.database.DatabaseException: Failed to parse node with class例外：

dbRef.setValue(footballer.getFullName(), footballer);

dbRef被分配到集合的根目录：

DatabaseReference dbRef = database.getReference("footballers");

这是我的Footballer模型：

@IgnoreExtraProperties
public class Footballer {

    private String fullName;
    private String desc;
    private String photoUrl;
    private String teamUrl;

    public Footballer() {
    }

    public Footballer(String fullName, String desc, String photoUrl, String teamUrl) {
        this.fullName = fullName;
        this.desc = desc;
        this.photoUrl = photoUrl;
        this.teamUrl = teamUrl;
    }
    // getter-setter methods
}

以下是Firebase数据库的结构：

footballers
----Cristiano Ronaldo
--------fullName
--------desc
--------photoUrl
--------teamUrl

的build.gradle

apply plugin: 'com.android.application'

android {
    compileSdkVersion 26
    defaultConfig {
        applicationId "com.tk"
        minSdkVersion 23
        targetSdkVersion 26
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:26.1.0'
    implementation 'com.android.support.constraint:constraint-layout:1.0.2'
    implementation 'com.google.firebase:firebase-database:11.0.4'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.1'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'
    implementation 'com.android.support:recyclerview-v7:26.1.0'

    // Support Design Lib
    implementation 'com.android.support:design:26.1.0'

    // Swipe Action
    compile 'co.dift.ui.swipetoaction:library:1.1'
    // Facebook Fresco
    compile 'com.facebook.fresco:fresco:0.6.1'
}


apply plugin: 'com.google.gms.google-services'