Php 无法从Mysql列出我的Aandroid应用程序中的数据
我是Android开发的新手。我试图在android应用程序中执行数据库CRUD操作。 我可以成功地将数据插入mysql。我使用PHP和JSON对其进行解析。当数据插入数据库时，下一个活动应该是列出数据。问题是没有数据进入我的列出活动。只有活动没有数据。请帮帮我 在这段代码中，我试图显示三个数据，“name，price，description 从数据库mysql中检索数据，并将字符串转换为JSon对象。然后我的Java代码将调用JSon类并列出数据。我可以成功地将数据插入mysql。我正在使用PHP和JSon解析。当数据插入数据库时，下一个活动应该是列出数据。问题是没有数据出现进入我的列表活动。只有活动没有数据。 另外，我列出的产品的java代码是 公共类AllProductsActivity扩展了ListActivity{Php 无法从Mysql列出我的Aandroid应用程序中的数据,php,android,mysql,json,Php,Android,Mysql,Json,我是Android开发的新手。我试图在android应用程序中执行数据库CRUD操作。 我可以成功地将数据插入mysql。我使用PHP和JSON对其进行解析。当数据插入数据库时，下一个活动应该是列出数据。问题是没有数据进入我的列出活动。只有活动没有数据。请帮帮我 在这段代码中，我试图显示三个数据，“name，price，description 从数据库mysql中检索数据，并将字符串转换为JSon对象。然后我的Java代码将调用JSon类并列出数据。我可以成功地将数据插入mysql。我正在使用P
// Progress Dialog
private ProgressDialog pDialog;
// Creating JSON Parser object
JSONParser jParser = new JSONParser();
ArrayList<HashMap<String, String>> productsList;
// url to get all products list
private static String url_all_products = "http://10.0.2.2/get_all_products.php";
// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String TAG_PRODUCTS = "products";
private static final String TAG_PID = "pid";
private static final String TAG_NAME = "name";
// products JSONArray
JSONArray products = null;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.all_products);
// Hashmap for ListView
productsList = new ArrayList<HashMap<String, String>>();
// Loading products in Background Thread
new LoadAllProducts().execute();
// Get listview
ListView lv = getListView();
// on seleting single product
// launching Edit Product Screen
lv.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
String pid = ((TextView) view.findViewById(R.id.pid)).getText()
.toString();
// Starting new intent
Intent in = new Intent(getApplicationContext(),
EditProductActivity.class);
// sending pid to next activity
in.putExtra(TAG_PID, pid);
// starting new activity and expecting some response back
startActivityForResult(in, 100);
}
});
}
// Response from Edit Product Activity
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
// if result code 100
if (resultCode == 100) {
// if result code 100 is received
// means user edited/deleted product
// reload this screen again
Intent intent = getIntent();
finish();
startActivity(intent);
}
}
/**
* Background Async Task to Load all product by making HTTP Request
* */
class LoadAllProducts extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(AllProductsActivity.this);
pDialog.setMessage("Loading products. Please wait...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
pDialog.show();
}
/**
* getting All products from url
* */
protected String doInBackground(String... args) {
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
// getting JSON string from URL
JSONObject json = jParser.makeHttpRequest(url_all_products, "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
for (int i = 0; i < products.length(); i++) {
JSONObject c = products.getJSONObject(i);
// Storing each json item in variable
String id = c.getString(TAG_PID);
String name = c.getString(TAG_NAME);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_PID, id);
map.put(TAG_NAME, name);
// adding HashList to ArrayList
productsList.add(map);
}
} else {
// no products found
// Launch Add New product Activity
Intent i = new Intent(getApplicationContext(),
NewProductActivity.class);
// Closing all previous activities
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(i);
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
/**
* After completing background task Dismiss the progress dialog
* **/
protected void onPostExecute(String file_url) {
// dismiss the dialog after getting all products
pDialog.dismiss();
// updating UI from Background Thread
runOnUiThread(new Runnable() {
public void run() {
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(
AllProductsActivity.this, productsList,
R.layout.list_item, new String[] { TAG_PID,
TAG_NAME},
new int[] { R.id.pid, R.id.name });
// updating listview
setListAdapter(adapter);
}
});
}
}
}
Here in this code , am trying to display three data , "name, price, description. The PHP file will
retrieve the data from the database mysql , and convert the strings into JSon objects. Then my javacode will call the json class and list the data. I can successfully insert the data to the mysql.Am using PHP and JSON parsing for it.When the data inserted into database, the next activity should be listing the data.The problem is no data is coming into my listing activity. only the Activity is coming without data. kindly help me .
My JSON class for parsing or converting is as follows
This is my JSON parsing code .In this code first i created a function for get json from the url . then the code for making http request for GET and POST method by using if , else statement . In else method i put the code for get method . i converted it into json object , and the above android code will call it and display it in the activity..
I used a JSON Parser class to get JSON from URL. This class supports two http request methods GET and POST to get json from url.
As we are getting the JSON by making HTTP call, I am adding a Async method to make http calls on background thread. Add the follwing method in your main activity class
public JSONParser() {
}
// function get json from url
// by making HTTP POST or GET mehtod
public JSONObject makeHttpRequest(String url, String method,
List<NameValuePair> 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 {
if(isValidJson(json))
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.v("json String","Result => "+json);
}
// return JSON String
return jObj;
}
}
This is my JSON parsing code .In this code first i created a function for get json from the url . then the code for making http request for GET and POST method by using if , else statement . In else method i put the code for get method . i converted it into json object , and the above android code will call it and display it in the activity..
I used a JSON Parser class to get JSON from URL. This class supports two http request methods GET and POST to get json from url.
As we are getting the JSON by making HTTP call, I am adding a Async method to make http calls on background thread.
I used a JSON Parser class to get JSON from URL. This class supports two http request methods GET and POST to get json from url.
As we are getting the JSON by making HTTP call, I am adding a Async method to make http calls on background thread.
Since nothing is displayed in my activity. i have the following error in my logcat.
my logcat error is displayed below .
检查JSonObject是否具有产品的键值
03-10 03:49:54.491: W/System.err(1559): org.json.JSONException: No value for products
此错误显示的JSONobject没有products键值。检查日志猫的可能重复您可能会在第`Log.d行（“所有产品：”，json.toString（））；`@Blacktiger，，我不明白您的意思。您能再详细解释一下吗？我在日志猫中找不到打印
json.toString（）的json数据 03-10 03:49:54.491: W/System.err(1559): org.json.JSONException: No value for products