我面临一个问题，有效的 JSON 字符串不能成为 JSON 对象。
我已经测试了来自服务器的响应，它是一个有效的 JSON。
我在网上查了一下，是关于 UTF-8 with DOM 的问题。但即使我将 Notepad++ 中的字符集更改为没有 DOM 的 UTF-8，仍然会出现同样的错误。
我的代码：
<?php
require_once("Connection/conn.php");
//parse JSON and get input
$json_string = $_POST['json'];
$json_associative_array = json_decode($json_string,true);
$userId = $json_associative_array["userId"];
$password = $json_associative_array["password"];
$userType = $json_associative_array["userType"];
//get the resources
$json_output_array = array();
$sql = "SELECT * FROM account WHERE userId = '$userId' AND password = '$password' AND userType = '$userType'";
$result = mysql_query($sql);
//access success?
if (!$result) {
die('Invalid query: ' . mysql_error());
$json_output_array["status"] = "query failed";
}
else{
$json_output_array["status"] = "query success";
}
//find the particular user?
if (mysql_num_rows($result) > 0){
$json_output_array["valid"] = "yes";
}
else{
$json_output_array["valid"] = "no";
}
//output JSON
echo json_encode($json_output_array);
?>
安卓代码：
public boolean login() {
// instantiates httpclient to make request
DefaultHttpClient httpClient = new DefaultHttpClient();
// url with the post data
String url = SERVER_IP + "/gc/login.php";
JSONObject holder = new JSONObject();
try {
holder.put("userId", "S1");
holder.put("password", "s12345");
holder.put("userType", "supervisor");
} catch (JSONException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
Log.d("JSON", holder.toString());
// HttpPost
HttpPost httpPost = new HttpPost(url);
//FormEntity
ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
nameValuePairs.add(new BasicNameValuePair("json", holder.toString()));
try {
httpPost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
} catch (UnsupportedEncodingException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
// execution and response
boolean valid = false;
try {
HttpResponse response = httpClient.execute(httpPost);
Log.d("post request", "finished execueted");
String responseString = getHttpResponseContent(response);
Log.d("post result", responseString);
//parse JSON
JSONObject jsonComeBack = new JSONObject(responseString);
String validString = jsonComeBack.getString("valid");
valid = (validString.equals("yes"))?true:false;
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return valid;
}
private String getHttpResponseContent(HttpResponse response) {
String responseString = "";
try {
BufferedReader rd = new BufferedReader(new InputStreamReader(
response.getEntity().getContent()));
String line = "";
while ((line = rd.readLine()) != null) {
responseString += line ;
}
rd.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return responseString;
}
JSON来自服务器：
{
"status": "query success",
"valid": "yes"
}
取消格式化 JSON：
{"status":"query success","valid":"yes"}
当我将它复制到记事本++中时，它变成?{"status":"query success","valid":"yes"}
了似乎有一个不可见的字符。