Unable to pass list [Rest, XML, Android]

[netstart]

If i use this below source, to proces this json return ({"category":{"name":"Cagetory 1"}}) , i have problem too.


Source

	GsonHttpMessageConverter messageConverter = new GsonHttpMessageConverter();
	messageConverter.setSupportedMediaTypes(Collections
		.singletonList(MediaType.APPLICATION_JSON));
	List<HttpMessageConverter<?>> messageConverters = new ArrayList<HttpMessageConverter<?>>();
	messageConverters.add(messageConverter);
	restTemplate.setMessageConverters(messageConverters);

	// Perform the HTTP GET request to the Google search API
	CategoryRest response = restTemplate.postForObject(url, null,
		CategoryRest.class);
	categorias = response.getCategory();

StackTrace

11-10 18:07:48.974: ERROR/AndroidRuntime(973): FATAL EXCEPTION: AsyncTask #1
11-10 18:07:48.974: ERROR/AndroidRuntime(973): java.lang.RuntimeException: An error occured while executing doInBackground()
11-10 18:07:48.974: ERROR/AndroidRuntime(973):     at android.os.AsyncTask$3.done(AsyncTask.java:200)
11-10 18:07:48.974: ERROR/AndroidRuntime(973):     at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273)
11-10 18:07:48.974: ERROR/AndroidRuntime(973):     at java.util.concurrent.FutureTask.setException(FutureTask.java:124)
11-10 18:07:48.974: ERROR/AndroidRuntime(973):     at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307)
11-10 18:07:48.974: ERROR/AndroidRuntime(973):     at java.util.concurrent.FutureTask.run(FutureTask.java:137)
11-10 18:07:48.974: ERROR/AndroidRuntime(973):     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1068)
11-10 18:07:48.974: ERROR/AndroidRuntime(973):     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:561)
11-10 18:07:48.974: ERROR/AndroidRuntime(973):     at java.lang.Thread.run(Thread.java:1096)
11-10 18:07:48.974: ERROR/AndroidRuntime(973): Caused by: java.lang.NullPointerException
11-10 18:07:48.974: ERROR/AndroidRuntime(973):     at org.apache.harmony.luni.lang.reflect.ListOfTypes.length(ListOfTypes.java:47)
11-10 18:07:48.974: ERROR/AndroidRuntime(973):     at org.apache.harmony.luni.lang.reflect.ImplForType.toString(ImplForType.java:83)
11-10 18:07:48.974: ERROR/AndroidRuntime(973):     at java.lang.StringBuilder.append(StringBuilder.java:203)
11-10 18:07:48.974: ERROR/AndroidRuntime(973):     at com.google.gson.JsonDeserializerExceptionWrapper.deserialize(JsonDeserializerExceptionWrapper.java:57)
11-10 18:07:48.974: ERROR/AndroidRuntime(973):     at com.google.gson.JsonDeserializationVisitor.invokeCustomDeserializer(JsonDeserializationVisitor.java:92)
11-10 18:07:48.974: ERROR/AndroidRuntime(973):     at com.google.gson.JsonObjectDeserializationVisitor.visitFieldUsingCustomHandler(JsonObjectDeserializationVisitor.java:117)
11-10 18:07:48.974: ERROR/AndroidRuntime(973):     at com.google.gson.ReflectingFieldNavigator.visitFieldsReflectively(ReflectingFieldNavigator.java:63)
11-10 18:07:48.974: ERROR/AndroidRuntime(973):     at com.google.gson.ObjectNavigator.accept(ObjectNavigator.java:120)
11-10 18:07:48.974: ERROR/AndroidRuntime(973):     at com.google.gson.JsonDeserializationContextDefault.fromJsonObject(JsonDeserializationContextDefault.java:76)
11-10 18:07:48.974: ERROR/AndroidRuntime(973):     at com.google.gson.JsonDeserializationContextDefault.deserialize(JsonDeserializationContextDefault.java:54)
11-10 18:07:48.974: ERROR/AndroidRuntime(973):     at com.google.gson.Gson.fromJson(Gson.java:551)
11-10 18:07:48.974: ERROR/AndroidRuntime(973):     at com.google.gson.Gson.fromJson(Gson.java:498)
11-10 18:07:48.974: ERROR/AndroidRuntime(973):     at com.google.gson.Gson.fromJson(Gson.java:441)
11-10 18:07:48.974: ERROR/AndroidRuntime(973):     at org.springframework.http.converter.json.GsonHttpMessageConverter.readInternal(GsonHttpMessageConverter.java:140)
11-10 18:07:48.974: ERROR/AndroidRuntime(973):     at org.springframework.http.converter.AbstractHttpMessageConverter.read(AbstractHttpMessageConverter.java:148)
11-10 18:07:48.974: ERROR/AndroidRuntime(973):     at org.springframework.web.client.HttpMessageConverterExtractor.extractData(HttpMessageConverterExtractor.java:68)
11-10 18:07:48.974: ERROR/AndroidRuntime(973):     at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:470)
11-10 18:07:48.974: ERROR/AndroidRuntime(973):     at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:425)
11-10 18:07:48.974: ERROR/AndroidRuntime(973):     at org.springframework.web.client.RestTemplate.postForObject(RestTemplate.java:303)
11-10 18:07:48.974: ERROR/AndroidRuntime(973):     at com.impact.client.tablet.dat.request.CategoryRequest.oneCategory(CategoryRequest.java:48)
11-10 18:07:48.974: ERROR/AndroidRuntime(973):     at com.impact.client.tablet.dat.busca.OneCategoryDAT.doInBackground(OneCategoryDAT.java:22)
11-10 18:07:48.974: ERROR/AndroidRuntime(973):     at com.impact.client.tablet.dat.busca.OneCategoryDAT.doInBackground(OneCategoryDAT.java:1)
11-10 18:07:48.974: ERROR/AndroidRuntime(973):     at android.os.AsyncTask$2.call(AsyncTask.java:185)
11-10 18:07:48.974: ERROR/AndroidRuntime(973):     at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
11-10 18:07:48.974: ERROR/AndroidRuntime(973):     ... 4 more
11-10 18:07:49.034: WARN/ActivityManager(58):   Force finishing activity com.impact.client/.tablet.controller.cardapio.CardapioLayoutActivity
11-10 18:07:52.754: ERROR/WindowManager(973): Activity com.impact.client.tablet.controller.cardapio.CardapioLayoutActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@44f668c8 that was originally added here
11-10 18:07:52.754: ERROR/WindowManager(973): android.view.WindowLeaked: Activity com.impact.client.tablet.controller.cardapio.CardapioLayoutActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@44f668c8 that was originally added here
11-10 18:07:52.754: ERROR/WindowManager(973):     at android.view.ViewRoot.<init>(ViewRoot.java:247)
11-10 18:07:52.754: ERROR/WindowManager(973):     at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:148)
11-10 18:07:52.754: ERROR/WindowManager(973):     at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:91)
11-10 18:07:52.754: ERROR/WindowManager(973):     at android.view.Window$LocalWindowManager.addView(Window.java:424)
11-10 18:07:52.754: ERROR/WindowManager(973):     at android.app.Dialog.show(Dialog.java:241)
11-10 18:07:52.754: ERROR/WindowManager(973):     at com.impact.client.tablet.controller.cardapio.AAsyncActivityImplDefault.showProgressDialog(AAsyncActivityImplDefault.java:36)
11-10 18:07:52.754: ERROR/WindowManager(973):     at com.impact.client.tablet.controller.cardapio.AAsyncActivityImplDefault.showLoadingProgressDialog(AAsyncActivityImplDefault.java:26)
11-10 18:07:52.754: ERROR/WindowManager(973):     at com.impact.client.tablet.controller.cardapio.AAsyncActivity.showLoadingProgressDialog(AAsyncActivity.java:15)
11-10 18:07:52.754: ERROR/WindowManager(973):     at com.impact.client.tablet.dat.ADownloadTask.onPreExecute(ADownloadTask.java:32)
11-10 18:07:52.754: ERROR/WindowManager(973):     at android.os.AsyncTask.execute(AsyncTask.java:391)
11-10 18:07:52.754: ERROR/WindowManager(973):     at com.impact.client.tablet.controller.cardapio.CardapioLayoutModel.oneCategory(CardapioLayoutModel.java:22)
11-10 18:07:52.754: ERROR/WindowManager(973):     at com.impact.client.tablet.controller.cardapio.CardapioLayoutActivity$1.onClick(CardapioLayoutActivity.java:36)
11-10 18:07:52.754: ERROR/WindowManager(973):     at android.view.View.performClick(View.java:2408)
11-10 18:07:52.754: ERROR/WindowManager(973):     at android.view.View$PerformClick.run(View.java:8816)
11-10 18:07:52.754: ERROR/WindowManager(973):     at android.os.Handler.handleCallback(Handler.java:587)
11-10 18:07:52.754: ERROR/WindowManager(973):     at android.os.Handler.dispatchMessage(Handler.java:92)
11-10 18:07:52.754: ERROR/WindowManager(973):     at android.os.Looper.loop(Looper.java:123)
11-10 18:07:52.754: ERROR/WindowManager(973):     at android.app.ActivityThread.main(ActivityThread.java:4627)
11-10 18:07:52.754: ERROR/WindowManager(973):     at java.lang.reflect.Method.invokeNative(Native Method)
11-10 18:07:52.754: ERROR/WindowManager(973):     at java.lang.reflect.Method.invoke(Method.java:521)
11-10 18:07:52.754: ERROR/WindowManager(973):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
11-10 18:07:52.754: ERROR/WindowManager(973):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
11-10 18:07:52.754: ERROR/WindowManager(973):     at dalvik.system.NativeStart.main(Native Method)

[netstart]

If i use below source, Category is intanciate, but your properties is null.
I believe that this behavior may be related.

List<Category> categorias;
	/*
	 * This request return: {"category":{"name":"Cagetory 1"}}
	 */

	RestTemplate restTemplate = new RestTemplate();
	HttpHeaders requestHeaders = new HttpHeaders();
	List<MediaType> acceptableMediaTypes = new ArrayList<MediaType>();
	acceptableMediaTypes.add(MediaType.APPLICATION_JSON);
	requestHeaders.setAccept(acceptableMediaTypes);
	HttpEntity<?> requestEntity = new HttpEntity<Object>(requestHeaders);

	ResponseEntity<Category> responseEntity = restTemplate.postForEntity(url,
		requestEntity, Category.class);
	Category cat = responseEntity.getBody(); //cat is intanciate, but your properties is null
	categorias = new ArrayList<Category>();
	categorias.add(cat);

[Roy Clarkson]

The information in this JIRA may be helpful for JSON mapping with Jackson.

https://jira.springsource.org/browse/ANDROID-45