我正在尝试序列化一个ArrayList，以便在我关闭并重新启动我的App时，它可以与所有Claim Attributes一起使用。我收到标题中所示的错误。预期的begin_array但获得了begin_object。
这是我的代码：
@Override
protected void onStart(){
super.onStart();
claim = loadFromFile();
Toast.makeText(this, "loading File"+claim.size(), Toast.LENGTH_SHORT).show();
ClaimsList cl = new ClaimsList();
cl.setClaimList(claim);
//ArrayAdapter<Claim> claimAdapter = new ArrayAdapter<Claim>(this, R.layout.custom_view_claim, claim);
//listView.setAdapter(claimAdapter);
}
public void saveInFile(Claim claim) {
Gson gson = new Gson();
try {
FileOutputStream fos = openFileOutput(this.SAVEFILE,0);
OutputStreamWriter osw = new OutputStreamWriter(fos);
gson.toJson(claim, osw);
osw.flush();
fos.close();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
//recover those persistent data created in the save function
private ArrayList<Claim> loadFromFile() {
Gson gson = new Gson();
ArrayList<Claim> claim = new ArrayList<Claim>();
try {
FileInputStream fis = openFileInput(SAVEFILE);
//Based on http://google.gson.googlecode.com/svn/trunk/gson/dos/javadoc/com/google/gson/Gson.html
Type listType = new TypeToken<ArrayList<Claim>>(){}.getType();
InputStreamReader isr = new InputStreamReader(fis);
claim = gson.fromJson(isr, listType);
fis.close();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
if (claim == null){
claim = new ArrayList<Claim>();
}
return claim;
}
以下是我的班级贡献者：
ArrayList<Claim> claim;
String SAVEFILE = "file.sav";
最后是logCat：
02-01 16:50:45.121: E/AndroidRuntime(4695): FATAL EXCEPTION: main
02-01 16:50:45.121: E/AndroidRuntime(4695): Process: app.zioueche_travelexpense, PID: 4695
02-01 16:50:45.121: E/AndroidRuntime(4695): java.lang.RuntimeException: Unable to start activity ComponentInfo{app.zioueche_travelexpense/app.zioueche_travelexpense.AddClaim}: com.google.gson.JsonSyntaxException: java.lang.IllegalStateException: Expected BEGIN_ARRAY but was BEGIN_OBJECT at line 1 column 2 path $
02-01 16:50:45.121: E/AndroidRuntime(4695): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2305)
02-01 16:50:45.121: E/AndroidRuntime(4695): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2363)
02-01 16:50:45.121: E/AndroidRuntime(4695): at android.app.ActivityThread.access$900(ActivityThread.java:161)
02-01 16:50:45.121: E/AndroidRuntime(4695): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1265)
02-01 16:50:45.121: E/AndroidRuntime(4695): at android.os.Handler.dispatchMessage(Handler.java:102)
02-01 16:50:45.121: E/AndroidRuntime(4695): at android.os.Looper.loop(Looper.java:157)
02-01 16:50:45.121: E/AndroidRuntime(4695): at android.app.ActivityThread.main(ActivityThread.java:5356)
02-01 16:50:45.121: E/AndroidRuntime(4695): at java.lang.reflect.Method.invokeNative(Native Method)
02-01 16:50:45.121: E/AndroidRuntime(4695): at java.lang.reflect.Method.invoke(Method.java:515)
02-01 16:50:45.121: E/AndroidRuntime(4695): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1265)
02-01 16:50:45.121: E/AndroidRuntime(4695): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1081)
02-01 16:50:45.121: E/AndroidRuntime(4695): at dalvik.system.NativeStart.main(Native Method)
02-01 16:50:45.121: E/AndroidRuntime(4695): Caused by: com.google.gson.JsonSyntaxException: java.lang.IllegalStateException: Expected BEGIN_ARRAY but was BEGIN_OBJECT at line 1 column 2 path $
02-01 16:50:45.121: E/AndroidRuntime(4695): at com.google.gson.Gson.fromJson(Gson.java:822)
02-01 16:50:45.121: E/AndroidRuntime(4695): at com.google.gson.Gson.fromJson(Gson.java:775)
02-01 16:50:45.121: E/AndroidRuntime(4695): at app.zioueche_travelexpense.AddClaim.loadFromFile(AddClaim.java:273)
02-01 16:50:45.121: E/AndroidRuntime(4695): at app.zioueche_travelexpense.AddClaim.onStart(AddClaim.java:239)
02-01 16:50:45.121: E/AndroidRuntime(4695): at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1189)
02-01 16:50:45.121: E/AndroidRuntime(4695): at android.app.Activity.performStart(Activity.java:5436)
02-01 16:50:45.121: E/AndroidRuntime(4695): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2278)
02-01 16:50:45.121: E/AndroidRuntime(4695): ... 11 more
02-01 16:50:45.121: E/AndroidRuntime(4695): Caused by: java.lang.IllegalStateException: Expected BEGIN_ARRAY but was BEGIN_OBJECT at line 1 column 2 path $
02-01 16:50:45.121: E/AndroidRuntime(4695): at com.google.gson.stream.JsonReader.beginArray(JsonReader.java:350)
02-01 16:50:45.121: E/AndroidRuntime(4695): at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.read(CollectionTypeAdapterFactory.java:79)
02-01 16:50:45.121: E/AndroidRuntime(4695): at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.read(CollectionTypeAdapterFactory.java:60)
02-01 16:50:45.121: E/AndroidRuntime(4695): at com.google.gson.Gson.fromJson(Gson.java:810)
最佳答案
您可以使用以下功能：isJsonObject()和isJsonArray()
例如：
Gson gson = new Gson();
JsonParser parser = new JsonParser();
JsonElement jsonElement = parser.parse(productJSONStr);
if (jsonElement.isJsonArray()) {
}
else if (jsonElement.isJsonObject()) {
}else{
}
希望对您有所帮助。
关于java - 预期为BEGIN_ARRAY，但已为BEGIN_OBJECT Gson android可序列化，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/28269353/