Problème avec parser json pour objet java à l'aide de gson

Je veux analyser les données json en objet java à l'aide de google-gson.

Voici un exemple des données que je veux analyser:

  {"isBean":{"userName":"test","password":"password112"}}

IsBean.java

public interface IsBean extends Serializable,IsSerializable{

    long getId();

}

User.java

public class User implements IsBean,IsSerializable,Serializable {

    String userName;
    String password;

    public String getUserName() {
        return userName;
    }
    public void setUserName(String userName) {
        this.userName = userName;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    @Override
    public long getId() {
        return 0;
    }


}

RequestObj.java

public class RequestObj implements IsBean, Serializable,IsSerializable{

    IsBean  isBean;
    @Override
    public long getId() {
        return 0;
    }
     public IsBean getIsBean() {
        return isBean;
    }
    public void setIsBean(IsBean isBean) {
        this.isBean = isBean;
    }
}

Test.java

public class Test {

    public static void main(String[] args) {
        Gson gson = new Gson();
        User user=new User();
        user.setPassword("password112");
        user.setUserName("test");
        RequestObj requestObj=new RequestObj();
        requestObj.setIsBean(user);
        String jsonStr=gson.toJson(requestObj);
        System.out.println("jsonStr--->"+jsonStr);
        try{
            RequestObj request=gson.fromJson(jsonStr, RequestObj.class);
        }catch (Exception e) {
        e.printStackTrace();
        }
    }
}

Erreur:

java.lang.RuntimeException: Unable to invoke no-args constructor for interface com.test.gson.shared.IsBean. Register an InstanceCreator with Gson for this type may fix this problem.
at com.google.gson.internal.ConstructorConstructor$8.construct(ConstructorConstructor.java:167)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$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.Gson.fromJson(Gson.java:795)
at com.google.gson.Gson.fromJson(Gson.java:761)
at com.google.gson.Gson.fromJson(Gson.java:710)
at com.google.gson.Gson.fromJson(Gson.java:682)
at com.test.gson.server.Test.main(Test.java:18)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.google.gson.internal.UnsafeAllocator$1.newInstance(UnsafeAllocator.java:48)
at com.google.gson.internal.ConstructorConstructor$8.construct(ConstructorConstructor.java:164)
... 8 more
Caused by: java.lang.InstantiationException: com.test.gson.shared.IsBean
at sun.misc.Unsafe.allocateInstance(Native Method)
... 14 more

OriginalL'auteur bNd | 2012-12-14