我试图从sdcard解析json。当我尝试执行到异步任务简单适配器时,出现以下错误:
The method execute(String...) in the type AsyncTask<String,Void,SimpleAdapter> is not applicable for the arguments (StringBuilder)
我花了一个多星期的时间来解决这个问题,但是我没能成功。
我的代码是:
public class Jeans extends Activity {
private final String JSON_file = "country.json";
File jsonFile;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.baby1_1);
/** Getting Cache Directory */
File cDir = ExternalStorage.getSDCacheDir( this, "json_files" );
/** Getting a reference to temporary file, if created earlier */
jsonFile = new File(cDir.getPath() + "/" + JSON_file) ;
String strLine="";
StringBuilder strJson = new StringBuilder();
/** Reading contents of the temporary file, if already exists */
try {
FileReader fReader = new FileReader(jsonFile);
BufferedReader bReader = new BufferedReader(fReader);
/** Reading the contents of the file , line by line */
while( (strLine=bReader.readLine()) != null ){
strJson.append(strLine);
}
} catch (FileNotFoundException e) {
e.printStackTrace();
}catch(IOException e){
e.printStackTrace();
}
System.out.println(strJson);
/** The parsing of the xml data is done in a non-ui thread */
// ListViewLoaderTask listViewLoaderTask = new ListViewLoaderTask();
/** In here i'm getting the error */
new ListViewLoaderTask().execute(strJson);
}
private class ListViewLoaderTask extends AsyncTask<String, Void, SimpleAdapter>{
JSONObject jObject;
/** Doing the parsing of xml data in a non-ui thread */
@Override
protected SimpleAdapter doInBackground(String... strJson) {
try{
jObject = new JSONObject(strJson[0]);
CountryJSONParser countryJsonParser = new CountryJSONParser();
countryJsonParser.parse(jObject);
}catch(Exception e){
Log.d("JSON Exception1",e.toString());
}
CountryJSONParser countryJsonParser = new CountryJSONParser();
List<HashMap<String, String>> countries = null;
try{
/** Getting the parsed data as a List construct */
countries = countryJsonParser.parse(jObject);
}catch(Exception e){
Log.d("Exception",e.toString());
}
/** Keys used in Hashmap */
String[] from = { "country","flag","details"};
/** Ids of views in listview_layout */
int[] to = { R.id.tv_country,R.id.iv_flag,R.id.tv_country_details};
/** Instantiating an adapter to store each items
* R.layout.listview_layout defines the layout of each item
*/
SimpleAdapter adapter = new SimpleAdapter(getBaseContext(), countries, R.layout.lv_layout, from, to);
return adapter;
}
/** Invoked by the Android system on "doInBackground" is executed completely */
/** This will be executed in ui thread */
@Override
protected void onPostExecute(SimpleAdapter adapter) {
/** Getting a reference to listview of main.xml layout file */
ListView listView = ( ListView ) findViewById(R.id.lv_countries);
/** Setting the adapter containing the country list to listview */
listView.setAdapter(adapter);
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
请有人帮我解决这个密码。
最佳答案
您得到的错误是因为您没有传入字符串。
做:
/** In here i'm getting the error */
new ListViewLoaderTask().execute(strJson.toString());
请记住,在处理对象时,需要使用
toString()
方法来创建字符串。