php json_decode 在 webservice 调用后返回 NULL
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json_decode returns NULL after webservice call
提问by schouk
There is a strange behaviour with json_encodeand json_decodeand I can't find a solution:
有一个奇怪的行为json_encode和json_decode我不能找到一个解决方案：
My php application calls a php web service. The webservice returns json that looks like this:
我的 php 应用程序调用了一个 php web 服务。Web 服务返回如下所示的 json：
var_dump($foo):
string(62) "{"action":"set","user":"123123123123","status":"OK"}"
now I like to decode the json in my application:
现在我喜欢在我的应用程序中解码 json：
$data = json_decode($foo, true)
but it returns NULL:
但它返回NULL：
var_dump($data):
NULL
I use php5.
The Content-Type of the response from the webservice: "text/html; charset=utf-8"(also tried to use "application/json; charset=utf-8")
我使用php5。来自网络服务的响应的内容类型：（"text/html; charset=utf-8"也尝试使用"application/json; charset=utf-8"）
What could be the reason?
可能是什么原因？
回答by Pablo
Well, i had a similar issue and the problems was the PHP magic quotes in the server... here is my solution:
好吧，我有一个类似的问题，问题是服务器中的 PHP 魔术引号……这是我的解决方案：
if(get_magic_quotes_gpc()){
$param = stripslashes($_POST['param']);
}else{
$param = $_POST['param'];
}
$param = json_decode($param,true);
回答by Stefan Gehrig
EDIT:Just did some quick inspection of the string provided by the OP. The small "character" in front of the curly brace is a UTF-8 B(yte) O(rder) M(ark)0xEF 0xBB 0xBF. I don't know why this byte sequence is displayed as ?here.
编辑：刚刚对 OP 提供的字符串进行了一些快速检查。花括号前面的小“字符”是UTF-8 B(yte) O(rder) M(ark)0xEF 0xBB 0xBF。我不知道为什么这个字节序列显示在?这里。
Essentially the system you aquire the data from sends it encoded in UTF-8 with a BOM preceding the data. You should remove the first three bytes from the string before you throw it into json_decode()(a substr($string, 3)will do).
本质上，您从中获取数据的系统发送它以 UTF-8 编码，并在数据之前带有 BOM。在将字符串放入json_decode()（asubstr($string, 3)会做）之前，您应该从字符串中删除前三个字节。
string(62) "?{"action":"set","user":"123123123123","status":"OK"}"
^
|
This is the UTF-8 BOM
As Kuroki Kazediscovered, this character surely is the reason why json_decodefails. The string in its given form is not correctly a JSON formated structure (see RFC 4627)
正如黑木风发现的那样，这个角色肯定是json_decode失败的原因。其给定形式的字符串不是正确的 JSON 格式结构（请参阅RFC 4627）
回答by LarryBattle
Print the last json error when debugging.
调试时打印最后一个json错误。
json_decode( $so, true, 9 );
$json_errors = array(
JSON_ERROR_NONE => 'No error has occurred',
JSON_ERROR_DEPTH => 'The maximum stack depth has been exceeded',
JSON_ERROR_CTRL_CHAR => 'Control character error, possibly incorrectly encoded',
JSON_ERROR_SYNTAX => 'Syntax error',
);
echo 'Last error : ', $json_errors[json_last_error()], PHP_EOL, PHP_EOL;
回答by djb
None of the solutions above worked for me, but html_entity_decode($json_string)did the trick
上面的解决方案都不适合我，但html_entity_decode($json_string)成功了
回答by ólafur Waage
Try this
尝试这个
$foo = utf8_encode($foo);
$data = json_decode($foo, true);
回答by ikary
make sure that if you sent the data by POST / GET, the server has not escape the quotes
确保如果您通过 POST / GET 发送数据，则服务器没有转义引号
$my_array = json_decode(str_replace ('\"','"', $json_string), true);
回答by Kuroki Kaze
"?{"action":"set","user":"123123123123","status":"OK"}"
This little apostrophe in the beginning - what is it? First symbol after the doublequote.
开头的这个小撇号 - 是什么？双引号后的第一个符号。
回答by mona
I had the similar problem in a live site. In my local site it was working fine. For fixing the same I Just have added the below code
我在一个实时站点中遇到了类似的问题。在我的本地站点，它运行良好。为了修复相同的问题，我刚刚添加了以下代码
json_decode(stripslashes($_GET['arr']));
json_decode(stripslashes($_GET['arr']));
回答by Ivan Ivanovych Lukyanchuk
I just put this
我只是把这个
$result = mb_convert_encoding($result,'UTF-8','UTF-8');
$result = json_decode($result);
and it's working
它正在工作
回答by Matija
Yesterday I spent 2 hours on checking and fixing that error finally I found that in JSON string that I wanted to decode were '\' slashes. So the logical thing to do is to use stripslashes function or something similiar to different PL.
昨天我花了 2 个小时检查并修复该错误，最后我发现在 JSON 字符串中我想解码的是 '\' 斜杠。所以合乎逻辑的做法是使用stripslashes函数或类似不同PL的东西。
Of course the best way is sill to print this var out and see what it becomes after json_decode, if it is null you can also use json_last_error()function to determine the error it will return integer but here are those int described:
当然，最好的方法是打印这个 var 并查看它在 json_decode 之后变成什么，如果它是 null，你也可以使用json_last_error()函数来确定它将返回整数的错误，但这里是那些 int 描述：
0 = JSON_ERROR_NONE
0 = JSON_ERROR_NONE
1 = JSON_ERROR_DEPTH
1 = JSON_ERROR_DEPTH
2 = JSON_ERROR_STATE_MISMATCH
2 = JSON_ERROR_STATE_MISMATCH
3 = JSON_ERROR_CTRL_CHAR
3 = JSON_ERROR_CTRL_CHAR
4 = JSON_ERROR_SYNTAX
4 = JSON_ERROR_SYNTAX
5 = JSON_ERROR_UTF8
5 = JSON_ERROR_UTF8
In my case I got output of json_last_error() as number 4so it is JSON_ERROR_SYNTAX. Then I went and take a look into the string it self which I wanted to convert and it had in last line:
在我的例子中，我得到的 json_last_error() 输出为4，所以它是JSON_ERROR_SYNTAX。然后我去看看我想转换的字符串它自己，它在最后一行：
'\'title\' error ...'
After that is really just an easy fix.
在那之后真的只是一个简单的修复。
$json = json_decode(stripslashes($response));
if (json_last_error() == 0) { // you've got an object in $json}
