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java - 不使用 Gson、Jackson 等对 JSONArray 进行排序

转载 作者:行者123 更新时间:2023-12-01 15:11:00 24 4
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在我的应用程序中,下面的类接收 JSONArray 并使用其数据填充 ListView。我希望此 ListView 中的字段按字母顺序显示。所以我想在使用 JSONArray 的数据之前对其进行排序。

我看到一些主题建议使用 GSON 或 Jackson,但我正在尝试以更简单的方式做到这一点。我不太了解这些库,也没有在他们的教程中找到我需要的东西。

JSON 示例:

{"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"]}

我填充列表并等待用户的类方法:

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);
}
});




}

[编辑]为了从服务器请求数据,我使用这个 JSONParser 类 ():

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;

}

在这里,我在类(class)中收到了 JSON

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();
}
}
}

最佳答案

如果您有权访问服务器端代码,那么在那里对列表进行排序会更容易。如果没有,唯一的方法是将其解析为 ArrayList 并使用任何已知的算法对其进行简单排序。

关于java - 不使用 Gson、Jackson 等对 JSONArray 进行排序,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/12372590/

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