为什么我的服务器无法解析此JSON代码？

时间：2017-02-15 00:34:31

标签： ruby-on-rails json ruby parsing

我的服务器成功解析了一些JSON代码（因为丢失了）。我保留了结构，只是添加/更改了一些数据条目。现在，当我尝试解析它时，我的代码返回了以下错误：

JSON::ParserError in Static#testing4
Showing /home/user/website/app/views/static/testing4.html.erb where line #44 raised:

399: unexpected token at '  {
        "title": "TITLE1",
        "capital": "Rome",
        "length": 2.7,
        "date": "2017-1-2",
        "tags": [
          "Culture"
        ]
    }],
    "2": [
      {
        "title": "TITLE2",
        "capital": "Paris",
        "age": 1.2,
        "date": "2017-2-1",
        "tags": [
          "Culture"
        ]
    }]
}
'

这是我的代码。 问题是开头的{"1":[由于某种原因未被解析。此视图没有关联的控制器操作。

<!--testing4.html.erb-->
<%
require 'json'
require 'pp'

json = <<END_OF_JSON
{
    "1": [
      {
        "title": "TITLE1",
        "capital": "Rome",
        "length": 2.7,
        "date": "2017-1-2",
        "tags": [
          "Culture"
        ]
    }],
    "2": [
      {
        "title": "TITLE2",
        "capital": "Paris",
        "age": 1.2,
        "date": "2017-2-1",
        "tags": [
          "Culture"
        ]
    }]
}
END_OF_JSON


%>
<%= obj = JSON.parse(json) %>

尝试输出它而不解析它会产生以下结果： 

<%
require 'json'
require 'pp'

json = <<END_OF_JSON
{
    "1": [
      {
        "title": "TITLE1",
        "capital": "Rome",
        "length": 2.7,
        "date": "2017-1-2",
        "tags": [
          "Culture"
        ]
    }],
    "2": [
      {
        "title": "TITLE2",
        "capital": "Paris",
        "age": 1.2,
        "date": "2017-2-1",
        "tags": [
          "Culture"
        ]
    }]
}
END_OF_JSON


%>
PUTS: <%= puts json %><br>
PP: <%= pp json %>


---output---

PUTS: 
PP: { "1": [   {     "title": "TITLE1",     "capital": "Rome",     "length": 2.7,     "date": "2017-1-2",     "tags": [       "Culture"     ] }], "2": [   {     "title": "TITLE2",     "capital": "Paris",     "age": 1.2,     "date": "2017-2-1",     "tags": [       "Culture"     ] }] }

1 个答案:

答案 0 :(得分：2)

  

jsonlint不可靠，还是还有其他事情发生？

jsonlint是可靠的，ruby在解析你发布的json方面没有问题：

require 'json'
require 'pp' 

json = <<END_OF_JSON
{  
    "1": [
      {
        "title": "TITLE1",
        "capital": "Rome",
        "length": 2.7,
        "date": "2017-1-2",
        "tags": [
          "Culture"
        ]
    }],
    "2": [
      {
        "title": "TITLE2",
        "capital": "Paris",
        "age": 1.2,
        "date": "2017-2-1",
        "tags": [
          "Culture"
        ]
    }]
}
END_OF_JSON

obj = JSON.parse(json)
pp obj

--output:--

{"1"=>
  [{"title"=>"TITLE1",
    "capital"=>"Rome",
    "length"=>2.7,
    "date"=>"2017-1-2",
    "tags"=>["Culture"]}],
 "2"=>
  [{"title"=>"TITLE2",
    "capital"=>"Paris",
    "age"=>1.2,
    "date"=>"2017-2-1",
    "tags"=>["Culture"]}]}

但是，如果您查看文件或输出字符串，则非打印字符不一定是可见的：

test = "\001hello"
puts test
p test

--output:--
hello
"\u0001hello"

这里你会得到一个解析错误：

require 'json'
require 'pp' 

json = <<END_OF_JSON
{
    \001"1": [1, 2, 3]
}
END_OF_JSON

obj = JSON.parse(json)

即使输出时json看起来很好：

require 'json'
require 'pp' 

json = <<END_OF_JSON
{
    \001"1": [1, 2, 3]
}
END_OF_JSON

puts json
obj = JSON.parse(json)

--output:--
{
    "1": [1, 2, 3]
}

/Users/7stud/.rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/json/common.rb:156:in `parse': 784: unexpected token at '{ (JSON::ParserError)
    "1": [1, 2, 3]
}
'
    from /Users/7stud/.rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/json/common.rb:156:in `parse'
    from 1.rb:11:in `<main>'

因此，您可能希望从文件中读取json，然后使用p输出文本，然后检查文本是否有任何奇怪的字符。

另外，请复制并粘贴完整的错误消息 - 不要输入您认为错误消息的内容，然后声明这是您的程序生成的内容。我可以复制你用这个json发布的错误信息：

json = <<END_OF_JSON
(code) = {
    "1": [
      {
        "title": "TITLE1",
        "capital": "Rome",
        "length": 2.7,
        "date": "2017-1-2",
        "tags": [
          "Culture"
        ]
    }],
    "2": [
      {
        "title": "TITLE2",
        "capital": "Paris",
        "age": 1.2,
        "date": "2017-2-1",
        "tags": [
          "Culture"
        ]
    }]
}
END_OF_JSON

obj = JSON.parse(json)

--output:--
`parse': 784: unexpected token at '(code) = { (JSON::ParserError)
    "1": [
      {
        "title": "TITLE1",
        "capital": "Rome",
        "length": 2.7,
        "date": "2017-1-2",
        "tags": [
          "Culture"
        ]
    }],
    "2": [
      {
        "title": "TITLE2",
        "capital": "Paris",
        "age": 1.2,
        "date": "2017-2-1",
        "tags": [
          "Culture"
        ]
    }]
}
'
    from /Users/7stud/.rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/json/common.rb:156:in `parse'
    from 1.rb:29:in `<main>'

对评论1的回复：

错误消息包含rails正在看到的json，这里是：

399: unexpected token at '  {   #<===Opening brace, which starts a javascript object.
        "title": "TITLE1",
        "capital": "Rome",
        "length": 2.7,
        "date": "2017-1-2",
        "tags": [
          "Culture"
        ]
    }],   #<====First, a closing brace that ends the javascript object, followed by a closing bracket, ending what?
    "2": [
      {
        "title": "TITLE2",
        "capital": "Paris",
        "age": 1.2,
        "date": "2017-2-1",
        "tags": [
          "Culture"
        ] 
    }]
}

如果我将无效的json放在rails视图中：

<%
json = <<END_OF_JSON 
{
        "title": "TITLE1",
        "capital": "Rome",
        "length": 2.7,
        "date": "2017-1-2",
        "tags": [
          "Culture"
        ]
    }],
    "2": [
      {
        "title": "TITLE2",
        "capital": "Paris",
        "age": 1.2,
        "date": "2017-2-1",
        "tags": [
          "Culture"
        ]
    }]
}
END_OF_JSON

obj = JSON.parse(json)
%>

...然后在我的浏览器中输入将显示该视图的路径，这是我在浏览器中收到的错误消息：

Showing /Users/7stud/rails_projects/test4/app/views/users/index.html.erb where line #27 raised:

784: unexpected token at '{
        "title": "TITLE1",
        "capital": "Rome",
        "length": 2.7,
        "date": "2017-1-2",
        "tags": [
          "Culture"
        ]
    }],
    "2": [
      {
        "title": "TITLE2",
        "capital": "Paris",
        "age": 1.2,
        "date": "2017-2-1",
        "tags": [
          "Culture"
        ]
    }]
}
'

看起来很熟悉？如果你在json的其他地方有错误，就像这里：

<%
json = <<END_OF_JSON
{    
  "1": [
      {
        "title": "TITLE1",
        "capital": "Rome",
        "length": 2.7,
        "date": "2017-1-2",
        "tags": [
          "Culture"
        ]
      }
  ],
  "2":   #<====Missing opening bracket
    {
        "title": "TITLE2",
        "capital": "Paris",
        "age": 1.2,
        "date": "2017-2-1",
        "tags": [
          "Culture"
        ]
    }
  ]
}
END_OF_JSON

obj = JSON.parse(json)
%>

然后您会在浏览器中看到如下错误消息：

Showing /Users/7stud/rails_projects/test4/app/views/users/index.html.erb where line #32 raised:

784: unexpected token at '{    
  "1": [   #<===Note the presence of "1": [, unlike in your error message.
      {
        "title": "TITLE1",
        "capital": "Rome",
        "length": 2.7,
        "date": "2017-1-2",
        "tags": [
          "Culture"
        ]
      }
  ],
  "2":    
    {
        "title": "TITLE2",
        "capital": "Paris",
        "age": 1.2,
        "date": "2017-2-1",
        "tags": [
          "Culture"
        ]
    }
  ]
}
'

因此，导轨看到的json中不存在"1": [。如果您需要更多帮助，则需要复制并粘贴以下代码：

  1. 您的控制器和行动。
  2. 行动的观点。

    3. 对评论2的回复：

    rails视图能够呈现以下json而不会出现错误（删除所有空格）：

    <!--testing4.html.erb-->
<%
require 'json'
require 'pp'

json = <<END_OF_JSON
{
  "1": [{"title": "TITLE1", "capital": "Rome", "length": 2.7, "date": "2017-1-2", "tags": ["Culture"]}],
  "2": [{"title": "TITLE2", "capital": "Paris", "age": 1.2, "date": "2017-2-1", "tags": ["Culture"]}]
}
END_OF_JSON

%>
<%= obj = JSON.parse(json) %>

    并且，rails视图能够呈现以下json而不会出现错误（所有空格都重新添加）：

    <!--testing4.html.erb-->
<%
require 'json'
require 'pp'

json = <<END_OF_JSON
{
     "1": [
       {
         "title": "TITLE1", 
         "capital": "Rome", 
         "length": 2.7, 
         "date": "2017-1-2", 
         "tags": [
           "Culture"
         ]
     }],
     "2": [
       {
         "title": "TITLE2", 
         "capital": "Paris", 
         "age": 1.2, "date": 
         "2017-2-1", 
         "tags": [
           "Culture"
         ]
     }]
}
END_OF_JSON

%>
<%= obj = JSON.parse(json) %>

    但是，由于某种原因，rails视图无法呈现您的json：

    <!--testing4.html.erb-->
<%
require 'json'
require 'pp'

json = <<END_OF_JSON
{
    "1": [
      {
        "title": "TITLE1",
        "capital": "Rome",
        "length": 2.7,
        "date": "2017-1-2",
        "tags": [
          "Culture"
        ]
    }],
    "2": [
      {
        "title": "TITLE2",
        "capital": "Paris",
        "age": 1.2,
        "date": "2017-2-1",
        "tags": [
          "Culture"
        ]
    }]
}
END_OF_JSON


%>
<%= obj = JSON.parse(json) %>

    经过一些进一步调查后，你的json混合了ascii空格（十六进制表示法为20）和一种称为EM SPACE U+2003 e2 80 83 EM SPACE的UTF-8空格字符在UTF-8）。你的json中的第一个{ "1": [   { ^ | Right there 出现在这里：

    7b

    ...巧合的是，rails错误信息正在切断你的json。紧接在该开头括号（十六进制表示法中的20）之前是ascii空格（十六进制表示法中的EM SPACE），ascii空格前面的字符是一个三字节UTF-8字符，称为{{1 （U + 2003，UTF-8中的e2 80 83）。以UTF-8编码编码的字符应该是合法的json。 jsonlint接受EM SPACE，但是在它上面有阻塞。

    作为问题的一个简短示例，以下javascript数组在每个逗号后面都有EM SPACE：

    <!--testing4.html.erb-->  
<%
json = "[1, 2, 3]"
%>

<%= obj = JSON.parse(json) %>

    以下是我浏览器中的错误：

    419: unexpected token at ' 2, 3]'

    导轨错误会将json切断到第一个EM SPACE。

    事实证明，虽然json中允许使用UTF-8字符，但json术语之间只允许使用几个ascii空格字符 - 而不仅仅是任何UTF-8字符。见RFC 7159。在json术语之间使用EM SPACE在概念上等同于在术语之间使用z。因此，包含EM SPACE个字符的json是非法的json。在字符串中使用EM SPACE是合法的，但不能在json术语之间使用。

    以下jsonlinter报告带有EM SPACE字符的json无效：

    http://www.freeformatter.com/json-validator.html

    似乎有些jsonlinters比其他人更可靠。

    解决方案：

    您可以使用gsub()将所有EM SPACE字符替换为ascii空格：

    ...
...
END_OF_JSON

clean_json = json.gsub("\u2003", ' ')

%>
<%= obj = JSON.parse(clean_json) %>

    如果你从某个地方的服务中得到了json，你应该给他们发一封电子邮件，让他们知道他们发出的json是非法的。

相关问题
最新问题