如何解析ClassCastException:java.lang.String不能被强制转换为异常
我需要帮助。我有两种分享偏好的方法。它们是getList和setList 这是setList() 总共有19个值。 但是当我在fragment类中将值强制转换到recylerView的bindHolder时,我得到一个错误是如何解析ClassCastException:java.lang.String不能被强制转换为异常,java,android,string,list,classcastexception,Java,Android,String,List,Classcastexception,我需要帮助。我有两种分享偏好的方法。它们是getList和setList 这是setList() 总共有19个值。 但是当我在fragment类中将值强制转换到recylerView的bindHolder时,我得到一个错误是 java.lang.ClassCastException: java.lang.String cannot be cast to com.example.lscodex.ddddd.Model.tcmb 这是来自片段的异步任务 private class Download
java.lang.ClassCastException: java.lang.String cannot be cast to com.example.lscodex.ddddd.Model.tcmb
这是来自片段的异步任务
private class DownloadXmlTask extends AsyncTask<Void, Integer, List<tcmb>> {
@Override
protected void onPreExecute() {
super.onPreExecute();
mProgressBar.setVisibility(View.VISIBLE);
}
@Override
protected List<tcmb> doInBackground(Void... voids) {
return SharedPreferenceValues.getList(getActivity());
}
@Override
protected void onPostExecute(List<tcmb> tcmb) {
if (tcmb.size() == 0) {
mtcmbList = tcmb;
setupAdapter();
mRecyclerViewAnim.runLayoutAnimation(getContext(), mRecyclerView);
mProgressBar.setVisibility(View.INVISIBLE);
} else if (mRecyclerView != null) {
mtcmbList.addAll(tcmb);
Log.d(TAG, "onPostExecute: " + mtcmbList.size());
mRecyclerView.getAdapter().notifyDataSetChanged();
dateUpdate();
mRecyclerViewAnim.runLayoutAnimation(getContext(), mRecyclerView);
mProgressBar.setVisibility(View.INVISIBLE);
mSwipeRefreshLayout.setRefreshing(false);
}
}
}
我不知道为什么
编辑
我尝试使用共享的首选项,从初始屏幕获取XML列表数据,并将其导入到其他活动中
private class splashTask extends AsyncTask<Void, Integer, List<tcmb>> {
private Activity mContext;
public splashTask(Activity c){
this.mContext = c;
}
@Override
protected void onPreExecute() {
mSplashProgressBar.setProgress(0);
}
@Override
protected List<tcmbDoviz> doInBackground(Void... voids) {
List<tcmb> tcmbList = new ConnectionXmlParser().getXmlFile(getApplicationContext());
try {
int getvalues = ConnectionXmlParser.howLong();
Log.d(TAG, "doInBackground: " +getvalues);
for (int i=0;i<getvalues;i++){
Log.d(TAG, "doInBackground: " +i);
publishProgress(((int)i*100)/getvalues);
Log.d(TAG, "Publishing " + ((int)i*100/getvalues));
}
Thread.sleep(200);
} catch (InterruptedException e) {
e.printStackTrace();
}
return tcmbList;
}
@Override
protected void onPostExecute(List<tcmbDoviz> list) {
mtcmbList.addAll(list);
SharedPreferenceValues.setValuesList(getApplication(),mtcmbList);
splashScreen();
mSplashProgressBar.setVisibility(View.GONE);
}
@Override
protected void onProgressUpdate(Integer... values) {
mSplashProgressBar.setProgress(values[0]);
super.onProgressUpdate(values);
}
私有类splashTask扩展了AsyncTask{
私人活动mContext;
公共服务任务(活动c){
this.mContext=c;
}
@凌驾
受保护的void onPreExecute(){
mSplashProgressBar.setProgress(0);
}
@凌驾
受保护列表背景(无效…无效){
List tcmbList=newconnectionxmlparser().getXmlFile(getApplicationContext());
试一试{
int getvalues=ConnectionXmlParser.howLong();
Log.d(标记“doInBackground:+getvalues”);
对于(int i=0;i您正试图将List
更改为List
,问题就在这里
public static List<tcmb> getList(Activity a){
// your code
//
List<String> itemList = new ArrayList<String>();
itemList.addAll(Arrays.asList(itemWords));
dovizList = (List)itemsList;
Log.d(TAG, "getValuestcmb: " + dovizList.size());
return dovizList;
我发现了怎么做
在splashscreen.activity中保存具有共享首选项的XML列表对象
public static void setValues(Context context, List<tcmb> curProduct){
Gson gson = new Gson();
String jsonCurProduct = gson.toJson(curProduct);
SharedPreferences sharedPref = context.getSharedPreferences("Prefs", Context.MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPref.edit();
editor.putString("dd", jsonCurProduct);
editor.apply();
Log.d(TAG, "setValues: " + jsonCurProduct);
}
publicstaticvoidsetvalues(上下文、列表和产品){
Gson Gson=新的Gson();
字符串jsonCurProduct=gson.toJson(curProduct);
SharedReferences SharedReferences=context.getSharedReferences(“Prefs”,context.MODE\u PRIVATE);
SharedPreferences.Editor=sharedPref.edit();
putString(“dd”,jsonCurProduct);
editor.apply();
Log.d(标记“setValues:+jsonCurProduct”);
}
然后,获取片段中具有共享首选项的列表对象
public static List<tcmb> getValuesAltın(Context context){
Gson gson = new Gson();
List<tcmbDoviz> productFromShared = new ArrayList<>();
SharedPreferences sharedPref = context.getSharedPreferences("Prefs", Context.MODE_PRIVATE);
String jsonPreferences = sharedPref.getString("dd", "");
Type type = new TypeToken<List<tcmb>>() {}.getType();
productFromShared = gson.fromJson(jsonPreferences, type);
return productFromShared;
}
public静态列表getValuesAltın(上下文){
Gson Gson=新的Gson();
List productFromShared=new ArrayList();
SharedReferences SharedReferences=context.getSharedReferences(“Prefs”,context.MODE\u PRIVATE);
String jsonPreferences=sharedPref.getString(“dd”,“”);
Type Type=new-TypeToken(){}.getType();
productFromShared=gson.fromJson(jsonPreferences,type);
从共享中返回产品;
}
最后,谢谢你,拉维。我打错了你不懂的那行,很抱歉。我编辑了,但谢谢你的帮助。@lscodex我没听懂你的话??你能具体说说你在说什么吗?哪行?这行->列表项列表=新数组列表();我写了两次。我不知道确切情况,但我取了列表的值,我在logcat上看到。这些值我从列表中得到的是setValues中的字符串值。我正在将它们传输到getValuesList()中的tcmb对象列表。@lscodex没有这样的方法,你的意思是getValuesList
?不,该方法不传输任何内容。
private class splashTask extends AsyncTask<Void, Integer, List<tcmb>> {
private Activity mContext;
public splashTask(Activity c){
this.mContext = c;
}
@Override
protected void onPreExecute() {
mSplashProgressBar.setProgress(0);
}
@Override
protected List<tcmbDoviz> doInBackground(Void... voids) {
List<tcmb> tcmbList = new ConnectionXmlParser().getXmlFile(getApplicationContext());
try {
int getvalues = ConnectionXmlParser.howLong();
Log.d(TAG, "doInBackground: " +getvalues);
for (int i=0;i<getvalues;i++){
Log.d(TAG, "doInBackground: " +i);
publishProgress(((int)i*100)/getvalues);
Log.d(TAG, "Publishing " + ((int)i*100/getvalues));
}
Thread.sleep(200);
} catch (InterruptedException e) {
e.printStackTrace();
}
return tcmbList;
}
@Override
protected void onPostExecute(List<tcmbDoviz> list) {
mtcmbList.addAll(list);
SharedPreferenceValues.setValuesList(getApplication(),mtcmbList);
splashScreen();
mSplashProgressBar.setVisibility(View.GONE);
}
@Override
protected void onProgressUpdate(Integer... values) {
mSplashProgressBar.setProgress(values[0]);
super.onProgressUpdate(values);
}
public static List<tcmb> getList(Activity a){
// your code
//
List<String> itemList = new ArrayList<String>();
itemList.addAll(Arrays.asList(itemWords));
dovizList = (List)itemsList;
Log.d(TAG, "getValuestcmb: " + dovizList.size());
return dovizList;
List<String> itemsList = new ArrayList<String>();
dovizList = (List)itemsList;
List<String> itemsList = new ArrayList<String>();
List<tcmb> itemsList = new ArrayList<tcmb>();
dovizList = (List)itemsList;
public static void setValues(Context context, List<tcmb> curProduct){
Gson gson = new Gson();
String jsonCurProduct = gson.toJson(curProduct);
SharedPreferences sharedPref = context.getSharedPreferences("Prefs", Context.MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPref.edit();
editor.putString("dd", jsonCurProduct);
editor.apply();
Log.d(TAG, "setValues: " + jsonCurProduct);
}
public static List<tcmb> getValuesAltın(Context context){
Gson gson = new Gson();
List<tcmbDoviz> productFromShared = new ArrayList<>();
SharedPreferences sharedPref = context.getSharedPreferences("Prefs", Context.MODE_PRIVATE);
String jsonPreferences = sharedPref.getString("dd", "");
Type type = new TypeToken<List<tcmb>>() {}.getType();
productFromShared = gson.fromJson(jsonPreferences, type);
return productFromShared;
}