[英]Why am I getting an Unchecked Assignment Warning?
使用Gson將JSON字符串轉換為Java對象時,出現此警告。 為什么得到它,如何解決?
這是我在代碼中得到的警告:
Unchecked assignment:
'net.brawtasports.brawtasportsgps.model.JSONKeys' to
'net.brawtasports.brawtasportsgps.model.JSONKeys<net.brawtasports.brawtasportsgps.model.team.Object>'
這是我在運行時遇到的錯誤:
java.lang.ClassCastException:
com.google.gson.internal.LinkedTreeMap cannot be cast to
net.brawtasports.brawtasportsgps.model.team.Object
這是我的代碼:
String jsonString = Preferences.readFromPreferences(ApplicationConstants.team_data,"");
Gson gson = new Gson();
JSONKeys<Object> teamMembers = gson.fromJson(jsonString, JSONKeys.class); //converts json string to java object
Object players = teamMembers.getObject();//object is my custom class
//ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>(getActivity(),android.R.layout.simple_spinner_dropdown_item,players);
ArrayAdapter arrayAdapter = new ArrayAdapter(getActivity(),android.R.layout.simple_spinner_dropdown_item,players.getPlayersSummary());
player1.setAdapter(arrayAdapter);
這是我的JSONKeys POJO的代碼:
public class JSONKeys<T> {
private boolean Success;
private String Message;
private int ObjectIdentifier;
private T Object;
private java.util.List<List> List = new ArrayList<List>();
private int TotalRecords;
private String ErrorMessage;
private int Code;
private net.brawtasports.brawtasportsgps.model.match.Criteria Criteria;
private net.brawtasports.brawtasportsgps.model.match.SearchInfo SearchInfo;
//Add Object from match class
/**
* @return The Criteria
*/
public net.brawtasports.brawtasportsgps.model.match.Criteria getCriteria() {
return Criteria;
}
/**
* @param Criteria The Criteria
*/
public void setCriteria(net.brawtasports.brawtasportsgps.model.match.Criteria Criteria) {
this.Criteria = Criteria;
}
/**
* @return The SearchInfo
*/
public net.brawtasports.brawtasportsgps.model.match.SearchInfo getSearchInfo() {
return SearchInfo;
}
/**
* @param SearchInfo The SearchInfo
*/
public void setSearchInfo(net.brawtasports.brawtasportsgps.model.match.SearchInfo SearchInfo) {
this.SearchInfo = SearchInfo;
}
/**
* @return The List
*/
public java.util.List<List> getList() {
return List;
}
/**
* @param List The List
*/
public void setLArrayListList(java.util.List<List> List) {
this.List = List;
}
/**
* @return The Code
*/
public int getCode() {
return Code;
}
/**
* @param Code The Code
*/
public void setCode(int Code) {
this.Code = Code;
}
/**
* @return The TotalRecords
*/
public int getTotalRecords() {
return TotalRecords;
}
/**
* @param TotalRecords The TotalRecords
*/
public void setTotalRecords(int TotalRecords) {
this.TotalRecords = TotalRecords;
}
/**
* @return The ErrorMessage
*/
public String getErrorMessage() {
return ErrorMessage;
}
/**
* @param ErrorMessage The ErrorMessage
*/
public void setErrorMessage(String ErrorMessage) {
this.ErrorMessage = ErrorMessage;
}
/**
*
* @return
* The message
*/
public String getMessage() {
return Message;
}
/**
*
* @param message
* The message
*/
public void setMessage(String message) {
this.Message = message;
}
/**
*
* @return
* The Success
*/
public boolean isSuccess() {
return Success;
}
/**
*
* @param Success
* The Success
*/
public void setSuccess(boolean Success) {
this.Success = Success;
}
/**
*
* @return
* The ObjectIdentifier
*/
public int getObjectIdentifier() {
return ObjectIdentifier;
}
/**
*
* @param ObjectIdentifier
* The ObjectIdentifier
*/
public void setObjectIdentifier(int ObjectIdentifier) {
this.ObjectIdentifier = ObjectIdentifier;
}
/**
*
* @return
* The Object
*/
public T getObject() {
return Object;
}
/**
*
* @param Object
* The Object
*/
public void setObject(T Object) {
this.Object = Object;
}
}
對於我的對象POJO,它是:
public class Object {
private HomeTeamGoals HomeTeamGoals;
private AwayTeamGoals AwayTeamGoals;
private List<PlayersSummary> PlayersSummary = new ArrayList<PlayersSummary>();
private TeamSummary TeamSummary;
/**
*
* @return
* The HomeTeamGoals
*/
public HomeTeamGoals getHomeTeamGoals() {
return HomeTeamGoals;
}
/**
*
* @param HomeTeamGoals
* The HomeTeamGoals
*/
public void setHomeTeamGoals(HomeTeamGoals HomeTeamGoals) {
this.HomeTeamGoals = HomeTeamGoals;
}
/**
*
* @return
* The AwayTeamGoals
*/
public AwayTeamGoals getAwayTeamGoals() {
return AwayTeamGoals;
}
/**
*
* @param AwayTeamGoals
* The AwayTeamGoals
*/
public void setAwayTeamGoals(AwayTeamGoals AwayTeamGoals) {
this.AwayTeamGoals = AwayTeamGoals;
}
/**
*
* @return
* The PlayersSummary
*/
public List<PlayersSummary> getPlayersSummary() {
return PlayersSummary;
}
/**
*
* @param PlayersSummary
* The PlayersSummary
*/
public void setPlayersSummary(List<PlayersSummary> PlayersSummary) {
this.PlayersSummary = PlayersSummary;
}
/**
*
* @return
* The TeamSummary
*/
public TeamSummary getTeamSummary() {
return TeamSummary;
}
/**
*
* @param TeamSummary
* The TeamSummary
*/
public void setTeamSummary(TeamSummary TeamSummary) {
this.TeamSummary = TeamSummary;
}
}
反序列化泛型時,需要使用完全指定的類型。 他們需要更改的關鍵線在這里:
JSONKeys<Object> teamMembers = gson.fromJson(jsonString, JSONKeys.class);
因為您使用的是JSONKeys.class
,所以Gson不知道JSONKeys
的通用類型是JSONKeys
。 而是使用以下命令:
JSONKeys<Object> teamMembers = gson.fromJson(jsonString,
new TypeToken<JSONKeys<net.brawtasports.brawtasportsgps.model.team.Object>>(){}.getType());
這將告訴Gson您需要使用哪種泛型類型。 請參閱我的解釋以了解其工作原理: Gson TypeToken如何工作?
順便說一句,不要將您的類命名為與java.lang
包中的任何東西相同的名稱。 它會使您的代碼真正引起人們的閱讀混亂,並且當您由於忘記了import
語句而無意中引用了錯誤的代碼時,可能會導致無法預料的錯誤。
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