Is this valid JSON for parsing? - json
I've got a task to write a JSON parser in java with a little help.
I'm already able to parse this:
{
"ArrayWithOneString" : [ "ArrayContent" ],
"Array" : [
{
"ArrayinArray" : [
{
"NumberInArray" : 1337,
"StringInArray" : "String"
}
]
}
]
}
I've got only one last problem:
"string" : { // The bracket
"string" : "valueString"
},
My problem is that I expect a value and not another object for this opening bracket ({).
I wanted to ask if this is valid json before trying to parse it.
Yes it is valid. Well without your highlighting attempts, and assuming it is part of a parent object.
Just because you have a property called "string" doesn't mean it has to be a string value. I suggest perhaps whoever made it just isn't being very consistent, but it is still valid.
The question is, why are you expecting a value? Either the person who constructed the JSON has not done it to specification, or it is you that is not understanding the specification.
Also, you can easily validate JSON here.
Look here for specifications. Your example is valid according to this.
Yes it is valid JSON. You can now parse in your code.
You can check Valid JSON
See below screenshot.
Related
Solving this simple(?) JSONPath
I am new to this topic, but I hope you can help me. I can't figure out a correct JSON expression for solving my problem.
Given JSON structure (coming from zigbee2mqtt):
{
"message" : "announce",
"meta" : {
"friendly_name" : "Lamp1"
},
"type" : "device_announced"
}
What I am trying:
if $.type == 'device_announced' then return the friendly_name
which in this case is
Lamp1
If I understand correctly, you are looking for an expression like this: $[?(#.type=='device_announced')].meta.friendly_name So, we are filtering the root collection on types equal to the search string, and then drill down to the friendly_name. You can test this online here. Note: Some implementations require you to wrap your JSON in an array [ ] to allow this kind of filtering.
JSON schema conditional check in JSON object within array
Here is the desired schema and json for illustration purpose. Please see the link below.
JSON Schema and JSON
{
"id": "123" ,
"ts": "1234567890",
"complex_rules":
[
{
"type":"admin",
"rule":{
"rights":"all",
"remarks": "some admin remarks"
}
},
{
"type":"guest",
"rights": "limited"
},
{
"type":"anonymous",
"rights": "blocked"
}
]
}
The 'complex_rules' is an array of json object:
With type either be a : "admin", "guest", "anonymous" and the 'type' attribute is MANDATORY.
Each object in array can have its own structure, but the type can be either of: "admin", "guest", "anonymous" only. No other type attribute is acceptable.
The conditions to evaluate:
The type of object in the array cannot re-occur in the array. (I know this seems to be not possible, so we can ignore this)
If attribute "rights" in the {type=admin object} with any value, then we cannot have "rights": "limited" or any value in {type=guest object}. The JSON Schema validation must complain about this.
Another twist, either object {type":"guest"}or {type":"anonymous"} can exist. Both types cannot coexist along with other types.
----Update
The above link is the solution this question.
In regards to 1 and 2: You need to use a combination of if, then, and not keywords to construct the logic you require with the correct level of applicability. In regards to 3: The type of object in the array cannot re-occur in the array. (I know this seems to be not possible, so we can ignore this) Right, that's correct, it's not possible as of draft-7 JSON Schema.
set object value to another object in a JSON
I just wanted to know if I can do something like this in JSON:
{
"web" : {
"app_pub" : "localhost/public",
"app_lib" : "localhost/lib",
"app_assets" : "app_pub" + "/assets"
}
}
You can check your JSON, using validator, i.e.: https://jsonformatter.curiousconcept.com/ Your code doesn't correspond RFC4627 and others. You can't do operations inside JSON. P.S.: RFC4627 contains full JSON grammar.
Invalid JSON but validates on JSONLint
I have the following JSON which validates on JSONLint.com but when I pass it to JSON.parse() I get the error
SyntaxError: JSON.parse: unexpected character
...0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,...
This is apparently the last "correct": line
var theJSON = JSON.parse({
"data": [
{
"wrong": "0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0",
"correct": "0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0"
},
{
"wrong": "0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0",
"correct": "0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0"
},
{
"wrong": "0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0",
"correct": "0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0"
},
{
"wrong": "0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0",
"correct": "0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0"
}
]
});
You, like many, have confused JavaScript's literal syntax with JSON. This happens a lot as JSON uses a subset of JavaScript's literal syntax so it looks a lot alike. JSON, however, is always a string. It is a serialized data scheme for porting data structures between langs/platforms.
Also confusing is that a string of JSON which has been output by any platform can be copied and pasted right into JavaScript and used. Again, this is because of the shared syntax. Having pasted such output right into JavaScript, however, one is no longer using JSON--they are now writing JavaScript in literal syntax. That is, unless, you pasted it between quotes and properly escaped the resulting string. But there's no sense in doing so as then it needs to be parsed in order to end up with what you already had.
JSON.parse() is a method for unserializing data which had been serialized into JSON. It expects a string because, well, JSON is a string. You're passing an object (in literal syntax). It does not need parsing...it is already the thing you want.
Wrapping your object literal in single quotes would make the code work, but it would be pointless to do so as the parse would simply result in what you already have.
Your code would be better written if you replaced the variable named theJSON with one named theObject and made it look as such:
var theObject = {
data: [
{
wrong: "0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0",
correct: "0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0"
},
{
wrong: "0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0",
correct: "0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0"
},
{
wrong: "0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0",
correct: "0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0"
},
{
wrong: "0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0",
correct: "0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0"
}
]
};
Whatever code wanted to use the parse result should be fine once you've done it.
How to use JMS Message Transformation in ActiveMQ with Stomp/JSON
I am sending messages in JSON format to an ActiveMQ server. I am trying to use JMS Transformation to transform the JSON encoded object into a true Java Object in hopes of being able to use selectors on the data inside.
Here is a link to the documentation on Stomp and Message Transformation.
Here is a link to a discussion on the patch where someone shows an example of a legal JSON object
The format of the JSON objects I am sending (in pretty print) are similar to this:
{
"msg": {
"flag1" : "value1",
"flag2" : "value2"
}
}
The messages arrive in the message queue, but with the transformation-error property set to 'msg : msg'.
The only format accepted by the transformation jms-map-json or jms-object-json is a simple Map format, which in JSON is:
{"map" :
{"entry" :
[
{ "string1": [ "key1", "value1" ] },
{ "string2": [ "key2", "value2" ] }
]
}
}
This is the same format shown in the discussion forum. This format represents a name/value pair map object in java.
Selectors are only usable on Properties and Headers.
you can use any JSON notation for your jms-object-json transformations as long as XStream can handle it. You can take a look at test cases for some examples. There, we use SamplePojo class:
https://svn.apache.org/repos/asf/activemq/trunk/activemq-stomp/src/test/java/org/apache/activemq/transport/stomp/SamplePojo.java
which is properly annotated so it can be represented with the following JSON
{"pojo":{
"name":"Dejan",
"city":"Belgrade"
}}
You can try using the same approach for your classes.
Hope this helps,
Dejan
It should be mentioned that ActiveMQ version must at least 5.8, because with 5.6 version I had problem when transformation just did not work.