私のアプリでは、以下のクラスが JSONArray を受け取り、そのデータを使用して ListView を設定します。この ListView のフィールドをアルファベット順に表示したいと考えています。したがって、データを使用する前に JSONArray を並べ替えたいと思います。
GSON または Jackson の使用を提案するトピックをいくつか見ましたが、これをより簡単な方法で実行しようとしています。私はこれらのライブラリをよく理解しておらず、チュートリアルで必要なものを見つけられませんでした。
JSON の例:
{"0":["1","Alimentos e Bebidas","Y"],"1":["6","Beleza e Cosm\u00e9ticos","Y"],"2":
["11","Cama, Mesa e Banho","Y"],"3":["3","CDs, DVDs e Games","Y"],"4":["2","Convites
e Cortesias","Y"],"5":["23","Cursos","Y"],"6":["8","Eletr\u00f4nicos","Y"],"7":
["16","Esporte e Lazer","Y"],"8":["14","Inform\u00e1tica e Acess\u00f3rios","Y"],
"9":["10","Limpeza","Y"],"10":["4","Livros","Y"],"11":["21","Livros no Sebo","Y"],
"12":["5","Outros","Y"],"13":["12","Roupas e Acess\u00f3rios","Y"]}
リストにデータを入力してユーザーを待つクラスのメソッド:
public void proccess(){
listview = (ListView) findViewById(R.id.include3);
int qtdCategorias = json.length();
categorias = new String[qtdCategorias];
itens = new ArrayList<ItemListView>();
for (int i=0; i<qtdCategorias; i++){
c = json.optJSONArray(i);
String nomeCategoria = null;
try {
nomeCategoria = c.getString(1); //A consulta SQL do php retorna somente categorias habilitadas
} catch (JSONException e) {
Log.e("CategoriasShoppingActivity", e.toString());
e.printStackTrace();
}
categorias[i] = nomeCategoria;
//ItemListView item = new ItemListView(nomeCategoria);
//itens.add(item);
}
Arrays.sort(categorias);
for (int i=0; i<qtdCategorias; i++){
ItemListView item = new ItemListView(categorias[i]);
itens.add(item);
}
adapterListView = new AdapterListView(this, itens);
listview.setAdapter(adapterListView);
listview.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View v,
int position, long id) {
c = json.optJSONArray(position);
String name = null;
String idt = null;
try {
name = c.getString(1);
idt = c.getString(0);
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Intent in = new Intent(getApplicationContext(), ProdutosActivity.class);
in.putExtra(TAG_NAME, name);
in.putExtra(TAG_ID, idt);
startActivity(in);
}
});
}
[編集] サーバーからデータを要求するには、次の JSONParser クラス () を使用します。
public class JSONParser{
static InputStream is = null;
static JSONArray jArr = null;
static JSONStringer jArrString = null;
static String json = "";
private static Context context;
private ProgressDialog loader;
// static HttpEntity httpEntity = null;
// constructor
public JSONParser() {
}
public JSONArray getJSONFromUrl(String url, List<NameValuePair> params) {
// Making HTTP request
try {
// defaultHttpClient
HttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
httpPost.setEntity(new UrlEncodedFormEntity(params));
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
// json = EntityUtils.toString(httpEntity);
// HttpEntity httpEntity2 = httpEntity;
json = EntityUtils.toString(httpEntity);
// is = httpEntity.getContent();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
Log.e("JSONParser", "IOException "+e.toString());
e.printStackTrace();
}
try {
char[] c = new char[json.length()];
json.getChars(0, json.length(), c, 0);
int i = 0;
while (c[i] == '\u00EF' || c[i] == '\u00BB' || c[i] == '\u00BF') { // remove
// utf-8
// BOM
i++;
}
json = json.substring(i);
Log.e("JSON", json);
} catch (Exception e) {
Log.e("Buffer Error", "Error converting result " + e.toString());
}
// try parse the string to a JSON object
try {
JSONObject json_data = new JSONObject(json);
JSONArray hashMap_names = json_data.names();
JSONArray hashMap_names2 = new JSONArray();
Map hashMap = new HashMap(json_data.length());
for (int i = 0; i != hashMap_names.length(); i++) {
hashMap.put(String.valueOf(i), json_data.get(String.valueOf(i)));
hashMap_names2.put(String.valueOf(i));
}
JSONObject hashMap_obj = new JSONObject(hashMap);
jArr = hashMap_obj.toJSONArray(hashMap_names2);
// jArr = new JSONArray(json);
Log.e("JSON Parser", "succesful parsing data " + jArr.toString());
} catch (Exception e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
jArr = null;
}
// return JSON String
return jArr;
}
そしてここで、クラスで JSON を受け取ります
protected void onActivityResult(int requestCode, int resultCode, Intent data){
if (requestCode == 1){
if (resultCode == RESULT_OK){
try {
json = new JSONArray(data.getStringExtra(TAG_JSON));
Log.e("CategoriasShoppingActivity", "JSON: "+json);
} catch (JSONException e) {
e.printStackTrace();
}
proccess();
}else{ // resultCode == RESULT_CANCELED
Log.d("CategoriasJogarActivity", "AsyncTaskActicity retornou RESULT_CANCELED");
finish();
}
}
}