[英]Android Studio parsing JSON
Im trying to develope an android app which will connect to an external server to get the data. 我正在尝试开发一个Android应用程序,该应用程序将连接到外部服务器以获取数据。 I have successfully read the data with my .php file but I can't use it in my app because it throws an error. 我已经成功读取了.php文件中的数据,但是由于抛出错误,因此无法在我的应用中使用它。
<?php
/**
* A class file to connect to database
*/
// connect to database
try {
$pdo = new PDO('mysql:host=localhost;dbname=myDBname',' user', 'pass');
$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$pdo->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
} catch(PDOException $err) {
die($err->getMessage());
}
$stmt = $pdo->prepare("select * from Test");
$result = $stmt->execute();
print_r($stmt->fetchAll(PDO::FETCH_ASSOC));
?>
That's the php code I use to read the data. 那就是我用来读取数据的php代码。 And this is the code I use in Android Studio 这是我在Android Studio中使用的代码
protected String doInBackground(String... args) {
// Building Parameters
List params = new ArrayList();
// getting JSON string from URL
JSONObject json = jParser.makeHttpRequest(server_php_url, "GET", params);
// Check your log cat for JSON reponse
Log.d("All Products: ", json.toString());
try {
// Checking for SUCCESS TAG
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// products found
// Getting Array of Products
products = json.getJSONArray(TAG_PRODUCTS);
// looping through All Products
//Log.i("ramiro", "produtos.length" + products.length());
for (int i = 0; i < products.length(); i++) {
JSONObject c = products.getJSONObject(i);
// Storing each json item in variable
String name = c.getString(TAG_NAME);
// creating new HashMap
HashMap map = new HashMap();
// adding each child node to HashMap key => value
map.put(TAG_NAME, name);
empresaList.add(map);
}
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
This is JSONParser class: 这是JSONParser类:
public class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// constructor
public JSONParser() {
}
// function get json from url
// by making HTTP POST or GET mehtod
public JSONObject makeHttpRequest(String url, String method,
List params) {
// Making HTTP request
try {
// check for request method
if(method == "POST"){
// request method is POST
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
httpPost.setEntity(new UrlEncodedFormEntity(params));
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
}else if(method == "GET"){
// request method is GET
DefaultHttpClient httpClient = new DefaultHttpClient();
String paramString = URLEncodedUtils.format(params, "utf-8");
url += "?" + paramString;
HttpGet httpGet = new HttpGet(url);
HttpResponse httpResponse = httpClient.execute(httpGet);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
}
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
json = sb.toString();
} catch (Exception e) {
Log.e("Buffer Error", "Error converting result " + e.toString());
}
// try parse the string to a JSON object
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
// return JSON String
return jObj;
}
}
This is the result of JSON: 这是JSON的结果:
Array ( [0] => Array ( [Test] => Name1 ) [1] => Array ( [Name] => Name2 ) )
The error is : 错误是:
E/JSON Parser﹕ Error parsing data org.json.JSONException: Value Array of type java.lang.String cannot be converted to JSONObject
I really need help. 我真的需要帮助 Thank you in advance. 先感谢您。
在返回变量中使用json_decode(),您将获得json格式的输出,如下所示:
return json_decode(jObj);
Retrun json object in do in background method 在后台方法中重做json对象
protected String doInBackground(String... args) {
// Building Parameters
List params = new ArrayList();
// getting JSON string from URL
JSONObject json = jParser.makeHttpRequest(server_php_url, "GET", params);
// Check your log cat for JSON reponse
Log.d("All Products: ", json.toString());
try {
// Checking for SUCCESS TAG
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// products found
// Getting Array of Products
products = json.getJSONArray(TAG_PRODUCTS);
// looping through All Products
//Log.i("ramiro", "produtos.length" + products.length());
for (int i = 0; i < products.length(); i++) {
JSONObject c = products.getJSONObject(i);
// Storing each json item in variable
String name = c.getString(TAG_NAME);
// creating new HashMap
HashMap map = new HashMap();
// adding each child node to HashMap key => value
map.put(TAG_NAME, name);
empresaList.add(map);
}
}
} catch (JSONException e) {
e.printStackTrace();
}
return json;
As far as I know the error is thrown in JSONParser class most specifically in : 据我所知,该错误是在JSONParser类中最具体地抛出:
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
I have finally encoded the output to [{"Test":"Name1"}] and now my error has changed to Error parsing data org.json.JSONException: Value [{"Test":"Name1"}] of type org.json.JSONArray cannot be converted to JSONObject 我终于将输出编码为[{“ Test”:“ Name1”}],现在我的错误已更改为解析数据org.json.JSONException的错误:org类型的值[{“ Test”:“ Name1”}]]。 json.JSONArray无法转换为JSONObject
I would apreciate if you could post the same .php code with mysql because I have tried to write it but it says "mysql is deprecated" and I dont know how to do it with mysqli. 如果您可以使用mysql发布相同的.php代码,我将不胜感激,因为我尝试编写它,但是它说“ mysql已过时”,而且我不知道如何使用mysqli。
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