java.lang.NoClassDefFoundError：android/media/Image android/firebase

Question

我是Android的初級用戶，我想在listView中顯示錶格。我的表poster包含三個字段：image，status和username。我試過這段代碼，但我有這個錯誤，我在stackoverflow搜索，但我沒有找到這種類型的錯誤，我認爲這個問題在image字段，謝謝。

java.lang.NoClassDefFoundError: android/media/Image 
at java.lang.Class.getDeclaredFields(Native Method) 
at java.lang.Class.getPublicFieldsRecursive(Class.java:846) 
at java.lang.Class.getFields(Class.java:829) 
at com.google.android.gms.internal.zzbtg$zza.<init>(Unknown Source) 
at com.google.android.gms.internal.zzbtg.zzi(Unknown Source) 
at com.google.android.gms.internal.zzbtg.zze(Unknown Source) 
at com.google.android.gms.internal.zzbtg.zzb(Unknown Source) 
at com.google.android.gms.internal.zzbtg.zza(Unknown Source) 
at com.google.firebase.database.DataSnapshot.getValue(Unknown Source) 

at com.example.root.guidetouristique.PosteGestion$1.onChildAdded(PosteGestion.java:36) 
at com.google.android.gms.internal.zzbox.zza(Unknown Source) 
at com.google.android.gms.internal.zzbqx.zzZV(Unknown Source) 
at com.google.android.gms.internal.zzbra$1.run(Unknown Source) 
at android.os.Handler.handleCallback(Handler.java:615) 
at android.os.Handler.dispatchMessage(Handler.java:92) 
at android.os.Looper.loop(Looper.java:137) 
at android.app.ActivityThread.main(ActivityThread.java:4745) 
at java.lang.reflect.Method.invokeNative(Native Method) 
at java.lang.reflect.Method.invoke(Method.java:511) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) 
at dalvik.system.NativeStart.main(Native Method) 
Caused by: java.lang.ClassNotFoundException: android.media.Image 
at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:61) 
at java.lang.ClassLoader.loadClass(ClassLoader.java:501) 
at java.lang.ClassLoader.loadClass(ClassLoader.java:461) 
at java.lang.Class.getDeclaredFields(Native Method)  
at java.lang.Class.getPublicFieldsRecursive(Class.java:846)  
at java.lang.Class.getFields(Class.java:829)  
at com.google.android.gms.internal.zzbtg$zza.<init>(Unknown Source)  
at com.google.android.gms.internal.zzbtg.zzi(Unknown Source)  
at com.google.android.gms.internal.zzbtg.zze(Unknown Source)  
at com.google.android.gms.internal.zzbtg.zzb(Unknown Source)  
at com.google.android.gms.internal.zzbtg.zza(Unknown Source)  
at com.google.firebase.database.DataSnapshot.getValue(Unknown Source)  
at com.example.root.guidetouristique.PosteGestion$1.onChildAdded(PosteGestion.java:36) 

我在PosteGestion.java代碼：

@Override 
    public void onChildAdded(DataSnapshot dataSnapshot, String s) { 
     Post p = dataSnapshot.getValue(Post.class); 
     if(p!=null){ 
      affichage.add(p); 
     } 
     else{ 
      DR=FBD.getReference(); 
      return; 

    } 
    } 

Post.java

public class Post { 
public Image image; 
public String userName; 
public String imagePost; 
public String status ; 

public Post(String userName, String imagePost, String status) { 
    this.userName = userName; 
    this.imagePost = imagePost; 
    this.status = status; 
} 

public Post(Image image, String userName, String imagePost, String status) { 
    this.image = image; 
    this.userName = userName; 
    this.imagePost = imagePost; 
    this.status = status; 

} 

public Post(String userName, String status) { 
    this.userName = userName; 
    this.status = status; 
} 

public Post() { 
    this.image=null; 
    this.imagePost=null; 
    this.userName=null; 
    this.status=null; 
} 

@Override 
public String toString() { 
    return "Post{" + 
      "image=" + image + 
      ", userName='" + userName + '\'' + 
      ", imagePost='" + imagePost + '\'' + 
      ", status='" + status + '\'' + 
      '}'; 
} 
} 

Answer 1

你Post.java類引用類android.media.Image。正如您在javadoc for Post中看到的那樣，它被添加到API級別19（Kit Kat）中。

可能發生了什麼是您正在模擬器或API級別較低的設備上運行您的代碼，這意味着該類不可用。

是android.media.Image真的是你想存儲在你的Post對象中嗎？無論如何，Firebase SDK無法加載和存儲該字段到數據庫。