Как правильно передать JSON из JSTL в Java Script?

Question

[Николай Бараненко]

Здравствуйте.

Пытаюсь из JSP передать JSON.

<c:set var="json_text">
    [{"TIME_STAMP": "2016-07-25 02:30:22", "COUNTER": "COUNT_ALL", "VALUE": 635 }, { "TIME_STAMP": "2016-07-25 02:30:22", "COUNTER": "COUNT_BAD", "VALUE": 1 }, { "TIME_STAMP": "2016-07-25 02:30:22", "COUNTER": "QUALITY", "VALUE": 99.84 }, { "TIME_STAMP": "2016-07-25 02:31:22", "COUNTER": "COUNT_ALL", "VALUE": 642 }, { "TIME_STAMP": "2016-07-25 02:31:22", "COUNTER": "COUNT_BAD", "VALUE": 1 }, { "TIME_STAMP": "2016-07-25 02:31:22", "COUNTER": "QUALITY", "VALUE": 99.84 }]
    </c:set>

 <script type="text/javascript">
var jsonString='<c:out value="${json_text}"/>';
var jsonObj = JSON.parse(jsonString);
</script>

Воспроизводится ошибка
Uncaught SyntaxError: Unexpected token & in JSON at position 2

НО если взять и целиком скопировать содержимое
напрямую в Java script, то все работает.

<script type="text/javascript">
var jsonString='[{"TIME_STAMP": "2016-07-25 02:30:22", "COUNTER": "COUNT_ALL", "VALUE": 635 }, { "TIME_STAMP": "2016-07-25 02:30:22", "COUNTER": "COUNT_BAD", "VALUE": 1 }, { "TIME_STAMP": "2016-07-25 02:30:22", "COUNTER": "QUALITY", "VALUE": 99.84 }, { "TIME_STAMP": "2016-07-25 02:31:22", "COUNTER": "COUNT_ALL", "VALUE": 642 }, { "TIME_STAMP": "2016-07-25 02:31:22", "COUNTER": "COUNT_BAD", "VALUE": 1 }, { "TIME_STAMP": "2016-07-25 02:31:22", "COUNTER": "QUALITY", "VALUE": 99.84 }]';
var jsonObj = JSON.parse(jsonString);
</script>

Подскажите где я допускаю ошибку.

Answer 1

[Evhen]

JSON - это объект JS, и в вашем случае не нужно его сначала представлять как строку и потом парсить с помощью JSON.parse.

Вот так должно быть норм.

<c:set var="json_text">
    [{"TIME_STAMP": "2016-07-25 02:30:22", "COUNTER": "COUNT_ALL", "VALUE": 635 }, { "TIME_STAMP": "2016-07-25 02:30:22", "COUNTER": "COUNT_BAD", "VALUE": 1 }, { "TIME_STAMP": "2016-07-25 02:30:22", "COUNTER": "QUALITY", "VALUE": 99.84 }, { "TIME_STAMP": "2016-07-25 02:31:22", "COUNTER": "COUNT_ALL", "VALUE": 642 }, { "TIME_STAMP": "2016-07-25 02:31:22", "COUNTER": "COUNT_BAD", "VALUE": 1 }, { "TIME_STAMP": "2016-07-25 02:31:22", "COUNTER": "QUALITY", "VALUE": 99.84 }]
    </c:set>

<script>
var jsonObj = ${json_text};
</script>

Answer 2

[Николай Бараненко]

Благодарю за помощь в решении, заработало

<script type="text/javascript">
    var jsonObj = ${json_text};
            var jsonResult = [];
            jsonResult.push("Вывод JSON="+'<c:out value="${json_text}"/>');
jsonResult.push("количество строк json="+jsonObj.length);
result_json.innerHTML = jsonResult.join('<br>');
 </script>