从Gsonstring创build对象不起作用

我想将一个对象传递给一个包。 现在我用GSON做了一个Json对象的转换。

该包被传递,包有正确的string表示,但是当我从string中创build对象时,我得到一个巨大的错误。

FATAL EXCEPTION: main java.lang.RuntimeException: Failed to invoke private android.net.Uri() with no args at com.google.gson.internal.ConstructorConstructor$3.construct(ConstructorConstructor.java:107) at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:162) at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.read(ReflectiveTypeAdapterFactory.java:93) at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:172) at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.read(TypeAdapterRuntimeTypeWrapper.java:40) at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.read(CollectionTypeAdapterFactory.java:81) at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.read(CollectionTypeAdapterFactory.java:60) at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.read(ReflectiveTypeAdapterFactory.java:93) at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:172) at com.google.gson.Gson.fromJson(Gson.java:803) at com.google.gson.Gson.fromJson(Gson.java:768) at com.google.gson.Gson.fromJson(Gson.java:717) at com.google.gson.Gson.fromJson(Gson.java:689) at com.test.fragment.QFragment.onCreateView(QFragment.java:54) at android.app.Fragment.performCreateView(Fragment.java:1788) at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:899) at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1101) at android.app.BackStackRecord.run(BackStackRecord.java:688) at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1559) at android.app.FragmentManagerImpl$1.run(FragmentManager.java:445) at android.os.Handler.handleCallback(Handler.java:730) at android.os.Handler.dispatchMessage(Handler.java:92) at android.os.Looper.loop(Looper.java:158) at android.app.ActivityThread.main(ActivityThread.java:5789) at java.lang.reflect.Method.invokeNative(Native Method) at java.lang.reflect.Method.invoke(Method.java:525) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1027) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:843) at dalvik.system.NativeStart.main(Native Method) Caused by: java.lang.InstantiationException: can't instantiate class android.net.Uri at java.lang.reflect.Constructor.constructNative(Native Method) at java.lang.reflect.Constructor.newInstance(Constructor.java:417) at com.google.gson.internal.ConstructorConstructor$3.construct(ConstructorConstructor.java:104)             at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:162)             at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.read(ReflectiveTypeAdapterFactory.java:93)             at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:172)             at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.read(TypeAdapterRuntimeTypeWrapper.java:40)             at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.read(CollectionTypeAdapterFactory.java:81)             at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.read(CollectionTypeAdapterFactory.java:60)             at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.read(ReflectiveTypeAdapterFactory.java:93)             at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:172)             at com.google.gson.Gson.fromJson(Gson.java:803)             at com.google.gson.Gson.fromJson(Gson.java:768)             at com.google.gson.Gson.fromJson(Gson.java:717)             at com.google.gson.Gson.fromJson(Gson.java:689)             at com.test.fragment.QFragment.onCreateView(QFragment.java:54)             at android.app.Fragment.performCreateView(Fragment.java:1788)             at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:899)             at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1101)             at android.app.BackStackRecord.run(BackStackRecord.java:688)             at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1559)             at android.app.FragmentManagerImpl$1.run(FragmentManager.java:445)             at android.os.Handler.handleCallback(Handler.java:730)             at android.os.Handler.dispatchMessage(Handler.java:92)             at android.os.Looper.loop(Looper.java:158)             at android.app.ActivityThread.main(ActivityThread.java:5789)             at java.lang.reflect.Method.invokeNative(Native Method)             at java.lang.reflect.Method.invoke(Method.java:525)             at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1027)             at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:843)             at dalvik.system.NativeStart.main(Native Method) 

我正在做这样的转换:

 public static QFragment newInstance(FModel oModel) { QFragment fragment = new QFragment(); fragment.mOModel = oModel; Bundle bdl = new Bundle(); bdl.putString("oModel", new Gson().toJson(oModel)); fragment.setArguments(bdl); return fragment; } 

并在我的片段上的createView:

  String jsonMyObject = null; Bundle args = this.getArguments(); if (args != null) { jsonMyObject = args.getString("oModel"); } mOrderModel = new Gson().fromJson(jsonMyObject, FModel.class); 

什么是解决这个问题的最好方法? 我需要更改为可序列化还是可以parcelable?

Solutions Collecting From Web of "从Gsonstring创build对象不起作用"

在FModel发现问题确实有一个Uri。

解决这个写作:

 public class UriSerializer implements JsonSerializer<Uri> { public JsonElement serialize(Uri src, Type typeOfSrc, JsonSerializationContext context) { return new JsonPrimitive(src.toString()); } } public class UriDeserializer implements JsonDeserializer<Uri> { @Override public Uri deserialize(final JsonElement src, final Type srcType, final JsonDeserializationContext context) throws JsonParseException { return Uri.parse(src.getAsString()); } } 

并像这样做Gson转换:

 Gson gson = new GsonBuilder() .registerTypeAdapter(Uri.class, new UriSerializer()) .create(); bdl.putString("oModel",gson.toJson(oModel)); 

并在此重build:

 Gson gson = new GsonBuilder() .registerTypeAdapter(Uri.class, new UriDeserializer()) .create(); jsonMyObject = args.getString("oModel"); mOrderModel = gson.fromJson(jsonMyObject, FModel.class); 

仅供参考,您可以通过将两个接口实现组合到同一个类中,同时使用序列化和反序列化。

 public class UriInOut implements JsonSerializer<Uri>, JsonDeserializer<Uri> { @Override public JsonElement serialize(Uri src, Type typeOfSrc, JsonSerializationContext context) { return new JsonPrimitive(src.toString()); } @Override public Uri deserialize(final JsonElement src, final Type srcType, final JsonDeserializationContext context) throws JsonParseException { return Uri.parse(src.getAsString()); } } .... new GsonBuilder() .registerTypeAdapter(Uri.class, new UriInOut()) .create(); 

您也可以使用更高效的 TypeAdapter

 public final class UriAdapter extends TypeAdapter<Uri> { @Override public void write(JsonWriter out, Uri uri) throws IOException { out.value(uri.toString()); } @Override public Uri read(JsonReader in) throws IOException { return Uri.parse(in.nextString()); } }