Java 无法跳转到firebase类型
我有上面这样的数据,我正试图为此编写POJO类,但它使Java 无法跳转到firebase类型,java,android,firebase,Java,Android,Firebase,我有上面这样的数据,我正试图为此编写POJO类,但它使 01-18 21:02:08.101 28838-28838/thamarai.techundefined.com E/AndroidRuntime﹕ FATAL EXCEPTION: main Process: thamarai.techundefined.com, PID: 28838 com.firebase.client.FirebaseException: Failed to bounce to type
01-18 21:02:08.101 28838-28838/thamarai.techundefined.com E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: thamarai.techundefined.com, PID: 28838
com.firebase.client.FirebaseException: Failed to bounce to type
at com.firebase.client.DataSnapshot.getValue(DataSnapshot.java:185)
at net.simplifiedcoding.imageuploadsample.ProcessImages$2.onDataChange(ProcessImages.java:144)
at com.firebase.client.core.ValueEventRegistration.fireEvent(ValueEventRegistration.java:53)
at com.firebase.client.core.view.DataEvent.fire(DataEvent.java:45)
at com.firebase.client.core.view.EventRaiser$1.run(EventRaiser.java:38)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5086)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
at dalvik.system.NativeStart.main(Native Method)
Caused by: com.fasterxml.jackson.databind.JsonMappingException: No suitable constructor found for type [simple type, class net.simplifiedcoding.imageuploadsample.ProcessImages$RetriveUserData]: can not instantiate from JSON object (need to add/enable type information?)
at [Source: java.io.StringReader@41c63110; line: 1, column: 2]
at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.deserializeFromObjectUsingNonDefault(BeanDeserializerBase.java:984)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserializeFromObject(BeanDeserializer.java:276)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:121)
at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:2888)
at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:2034)
at com.firebase.client.DataSnapshot.getValue(DataSnapshot.java:183)
at net.simplifiedcoding.imageuploadsample.ProcessImages$2.onDataChange(ProcessImages.java:144)
at com.firebase.client.core.ValueEventRegistration.fireEvent(ValueEventRegistration.java:53)
at com.firebase.client.core.view.DataEvent.fire(DataEvent.java:45)
at com.firebase.client.core.view.EventRaiser$1.run(EventRaiser.java:38)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5086)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
at dalvik.system.NativeStart.main(Native Method)
这是我的密码
ref.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot snapshot) {
Log.i("FireBase", "snapshot " + snapshot);
RetriveUserData data = snapshot.getValue(RetriveUserData.class);
Log.i("FireBase", "Data " + data.getAPIkey());
}
@Override
public void onCancelled(FirebaseError firebaseError) {
Log.i("FireBase", "The read failed: " + firebaseError.getMessage());
}
});
这是波乔
public class RetriveUserData {
private String fullName;
private String apikey;
public RetriveUserData() {
// empty default constructor, necessary for Firebase to be able to deserialize blog posts
}
public String getFullName() {
return fullName;
}
public String getAPIkey() {
return apikey;
}
}
更新
这是我得到的json(记录)
看起来我在做一个小问题,但不知道它在哪里 从堆栈跟踪:
原因:com.fasterxml.jackson.databind.JsonMappingException:找不到适合类型[simple type,class net.simplifiedcoding.imageuploadsample.ProcessImages$RetrieveUserData]的构造函数:无法从JSON对象实例化(需要添加/启用类型信息吗?)
由此看来,您已经将retrieveuserdata
嵌套在ProcessImages
类中。在这种情况下,Java将对外部类的隐式引用添加到retrieveuserdata
。由于您没有将该引用存储在Firebase中,它会抱怨找不到它
要清除此错误消息,请将retrieveuserdata
标记为static。这告诉Java不要生成引用:
public static class RetriveUserData {
从堆栈跟踪中:
原因:com.fasterxml.jackson.databind.JsonMappingException:找不到适合类型[simple type,class net.simplifiedcoding.imageuploadsample.ProcessImages$RetrieveUserData]的构造函数:无法从JSON对象实例化(需要添加/启用类型信息吗?)
由此看来,您已经将retrieveuserdata
嵌套在ProcessImages
类中。在这种情况下,Java将对外部类的隐式引用添加到retrieveuserdata
。由于您没有将该引用存储在Firebase中,它会抱怨找不到它
要清除此错误消息,请将retrieveuserdata
标记为static。这告诉Java不要生成引用:
public static class RetriveUserData {
堆栈跟踪不完整。请添加Entr堆栈跟踪,因为通常会有更多异常,这些异常指示实际原因。不过,我的初步猜测是,RetrieveUserData是一个内部类,在这种情况下,您需要将其标记为静态。请添加实际的JSON(而不是指向它的屏幕截图的链接)、最小的代码(现在我们缺少
ref
指向的内容)以及您得到的错误的完整堆栈跟踪。如果没有这些,我投票关闭,因为我们缺少一个完整的跟踪。@FrankvanPuffelen已添加完整跟踪,请检查它并添加json,因为堆栈跟踪不完整。请添加Entr堆栈跟踪,因为通常会有更多异常,这些异常指示实际原因。不过,我的初步猜测是,RetrieveUserData是一个内部类,在这种情况下,您需要将其标记为静态。请添加实际的JSON(而不是指向它的屏幕截图的链接)、最小的代码(现在我们缺少ref
指向的内容)以及您得到的错误的完整堆栈跟踪。没有这些我投票关闭,因为我们缺少了一个完整的跟踪。FrankvanPuffelen已经添加了完整的跟踪,请检查它并添加json