我只是不知道如何解决这个错误。它还在日志 cat 中显示错误“解析 Data.org.json.JSONException:End of input at character 0 of”。我没有安卓和所有的基础知识。但我真的需要这个。有人可以帮帮我吗？
这是我的 JSONParser.java
public class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
public JSONParser(){
}
public JSONObject getJSONFromUrl(final String url)
{
try
{
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
HttpResponse httpResponse = httpClient.execute(httpPost);
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
{
jObj = new JSONObject(json);
}
catch(JSONException e)
{
Log.e("JSON Parser", "Error Parsing Data " + e.toString());
}
return jObj;
}
public JSONObject makeHttpRequest(String url, String method, List<NameValuePair> params){
try{
if(method.equals("POST")){
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.equals("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{
jObj = new JSONObject(json);
}catch(JSONException e){
Log.e("JSON Parser", "Error Parsing Data." + e.toString());
}
return jObj;
}
}
这是我的 login.java
public class Login extends Activity implements OnClickListener{
private EditText user, pass;
private Button mSubmit;
private TextView mRegister;
private ProgressDialog pDialog;
JSONParser jsonParser = new JSONParser();
private static final String LOGIN_URL = "http://10.111.70.109/webservice/register.php";
private static final String TAG_SUCCESS = "success";
private static final String TAG_MESSAGE = "message";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
user = (EditText)findViewById(R.id.username);
pass = (EditText)findViewById(R.id.password);
mSubmit = (Button)findViewById(R.id.btnLogin);
mRegister = (TextView)findViewById(R.id.link_to_register);
mSubmit.setOnClickListener(this);
mRegister.setOnClickListener(this);
}
@Override
public void onClick(View v){
switch (v.getId()) {
case R.id.btnLogin:
new AttemptLogin().execute();
break;
case R.id.link_to_register:
Intent i = new Intent(getApplicationContext(), SignUp.class);
startActivity(i);
break;
default:
break;
}
}
class AttemptLogin extends AsyncTask<String, String, String>
{
boolean failure = false;
@Override
protected void onPreExecute(){
super.onPreExecute();
pDialog = new ProgressDialog(Login.this);
pDialog.setMessage("Please Wait. Attempting Login..");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show();
}
@Override
protected String doInBackground(String...args){
int success;
String username = user.getText().toString();
String password = pass.getText().toString();
try{
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("username", username));
params.add(new BasicNameValuePair("password", password));
Log.d("Request!", "Starting");
JSONObject json = jsonParser.makeHttpRequest(LOGIN_URL, "POST", params);
Log.d("Login Attempt..", json.toString());
success = json.getInt(TAG_SUCCESS);
if(success==1){
Log.d("Login Successful!", json.toString());
Intent i = new Intent(Login.this, MainActivity.class);
finish();
startActivity(i);
return json.getString(TAG_MESSAGE);
}else{
Log.d("Login Failure!", json.getString(TAG_MESSAGE));
return json.getString(TAG_MESSAGE);
}
}catch(JSONException e){
e.printStackTrace();
}
return null;
}
}
protected void onPostExecute(String file_url){
pDialog.dismiss();
if(file_url != null){
Toast.makeText(Login.this, file_url, Toast.LENGTH_LONG).show();
}
}
}
这是我用于登录的 php 脚本：
<?php
require("config.inc.php");
if(!empty($_POST))
{
$query = "SELECT username, email, password FROM students WHERE username =:username";
$query_params = array(':username'=>$_POST['username']);
try
{
$stmt = $db->prepare($query);
$result = $stmt->execute($query_params);
}
catch(PDOException $ex)
{
$response["success"] = 0;
$response["message"] = "Error. Please Try Again.";
die(json_encode($response));
}
$validated_info = false;
$row = $stmt->fetch();
if($row)
{
if($_POST['password']===$row['password'])
{
$login_ok = true;
}
}
if($login_ok)
{
$response["success"] = 1;
$response["message"] = "Login Successful!";
die(json_encode($response));
}else{
$response["success"] = 0;
$response["message"] = "Sorry. Please Try Again.";
die(json_encode($response));
}
}else{
?>
有谁能够帮助我？我真的很感激。