Text to Json in Java (list in text) - java

I have the following text which is returned by an API that I call:
{"identified_faces_names": "[\"omar\", \"elhoussinep\"]"}
when I pass this text to JSONParse to parse it, it give me the following exception:
Exception in thread "main" Unexpected character (o) at position 0.
Code used to parse the text to json:
String s = new String("{\"identified_faces_names\": \" [\"omar\",\"elhoussinep\"]\"}");
JSONParser parser = new JSONParser();
Object obj = parser.parse(s);

Did you definitely mean to enclose ["omar", "elhoussinep"] in quotes? Is that definitely intended to be a String value containing string quotes? Or is it intended to be an array of strings?
If identified_faces_names is intended to be an array of strings then the valid JSON is:
{
"identified_faces_names": [
"omar",
"elhoussinep"
]
}
This is parseable, without error, like so:
String s = new String("{\"identified_faces_names\": [\"omar\",\"elhoussinep\"]}");
JSONParser parser = new JSONParser();
Object obj = parser.parse(s);
If identified_faces_names is intended to be a String containing quotes you must escape the quotes inside the string. The valid JSON is:
{
"identified_faces_names": "[\\\"omar\\\",\\\"elhoussinep\\\"]"
}
This is parseable, without error, like so:
String s = new String("{\"identified_faces_names\": \" [\\\"omar\\\",\\\"elhoussinep\\\"]\"}");
JSONParser parser = new JSONParser();
Object obj = parser.parse(s);
So, in summary, I'd suggest revisiting the JSON to determine whether it is an array of strings or a string which contains quotes, if the latter then you have to escape those quotes.
FWIW, you can use JSONLint to check whether the JSON is valid. Using this you can see that your original JSON ({"identified_faces_names": "["omar","elhoussinep"]"}) was not valid and that the first invalid character is the "o" in "omar" and that's deemed invalid because it follows "[" which is deemed to be a complete String.

Use this String {"identified_faces_names": [\"omar\", \"elhoussinep\"]}. It is correct and will parse.

Related

JsonParser decoding the unicode

I am converting a JSON string into a JsonObject, by using JsonParser and JsonElement.
But my JSON string contains few Unicode escape sequence, and after parsing into JsonElement, Unicode escape sequence automatically converting into the actual element.
But I don't want to convert the Unicode escape sequence to the actual element after parsing.
JsonParser parser = new JsonParser();
JsonElement jsonElement = parser.parse(jsonString);
JsonObject jsonObject = jsonElement.getAsJsonObject();
jsonString is as below :
{
"config": {
"title": "Check the String \u0026 verify"
}
}
After parsing into JsonElement result is coming as below:
{"config":{"title":"Check the String & verify"}}
But I don't want to decode \u0026 into & after parsing.
Please suggest to me how I will resolve.
Note: I am using google gson to parse and create JsonElement, JsonObject
If you parse JSON with escape characters and you don't want them to be converted to the actual symbol, just escape the backslash.
"Check the String \u0026 verify" would then be "Check the String \\u0026 verify"
I know that it's a bad solution, but you can replace the \u0026 with \\u0026 before parsing it.
JsonElement jsonElement = JsonParser.parseString(jsonString.replaceAll("\\\\u([0-9a-fA-F]{4})", "\\\\\\\\u$1"));

Fetch String with special character from json using JSONObject

I have a JSON object with special character in it.
The format is as follows:
"field1": "result1", "field2": "\uabc\udef\ughi"
I get the string for each of the keys as
JSONObject jsonObj = new JSONObject();
String s1 = jsonObj.getString("field1");
String s2 = jsonObj.getString("field2");
When I print s2, I get weird characters as output. I know, "\u" is doing all the weirdness and I do not want that. I just want to get the string for field2 as it is. Sadly, I cannot modify the JSON object at source.
Any solution to this scenario.

Get string from JSON like PHP in Java

I was wondering if there is a way to get a string from JSON in Java like there is in PHP:
<?php
$json = #file_get_contents('example');
$decoded_json = json_decode($json);
echo $decoded_json->{"something"} ;
?>
I have currently tried:
String input = "[{"minecraft.net":"green"},{"session.minecraft.net":"green"},{"account.mojang.com":"green"},{"auth.mojang.com":"green"},{"skins.minecraft.net":"green"},{"authserver.mojang.com":"green"},{"sessionserver.mojang.com":"green"},{"api.mojang.com":"green"},{"textures.minecraft.net":"green"}]";
String wanted = "minecraft.net";
JSONObject json = new JSONObject(input);
String out = json.getString(wanted);
System.out.println(out);
However, it gives me this error:
org.json.JSONException: A JSONObject text must begin with '{' at 1 [character 2 line 1]
Thanks!
It's because your String is not a valid JSON object but a valid JSON array which contains objects, try to use JSONArray instead then you can query around this array for your desired object
You forgot to add \" when a double quote is inside another double quote

How to escape a colon inside a datetime value in a JSON string

I need to instantiate a JSONObject with a string that I receive from an external source. The string contains a datetime value, which in turn contains a colon.
When I try to create an instance of the JSONObject, I get an error, it looks like JSON does not like the colon in the middle of the date time value.
Here is a code snippet:
#Test
public void testGetDate()
{
String jsonStr = "{\"sDate\":2013-06-15T09:30:09+0000}";
try
{
JSONObject jsonObject = new JSONObject(jsonStr);
System.out.println(jsonObject.get("sDate"));
} catch (JSONException e)
{
e.printStackTrace();
}
}
The error I get is:
org.json.JSONException: Expected a ',' or '}' at 23 [character 24 line 1]
Has anyone encountered this ? Is there some way to escape the colon?
If you surround your date/time object in double quotes, it should accept it.
This should work:
String jsonStr = "{\"sDate\":\"2013-06-15T09:30:09+0000\"}";
Strings are required to be quoted in JSON:
string
""
" chars "
Your snippet is invalid, which is why the exception is thrown. You must surround the string value with double quotes.
The more interesting issue is for cases where the string is unknown. In case the format is known then it's reasonably easy to fix. Added as a utility to org.json here.

Json and Java. From String to JSONObject: issues

I'm using the library org.json.
I have a string like this (quotes can't appear in field_n)
{field1=value1, field2=value2} (say it `val`)
This string is obtained from an Hashtable<String, Object>.
I create a JSONObject from that string, obtaining:
{"field1":"value1", "field2":"value2"}
The issue arises when in the value value_n quotes (or newlines and carriage return) appear.
I've tried to escape the string in this way:
value = value.replace("\\", "\\\\");
value = value.replace("\"", "\\\"");
value = value.replace("\r", "\\r");
value = value.replace("\n", "\\n");
but I always obtain the org.json.JSONException: Expected a ',' or '}' at ... [character ... line 1] when I try to create the JSONObject with:
JSONObject json = new JSONObject(val);
In order to create JSON from map, use:
new JSONObject(myMap);
Another related issue:
quotedStr = JSONObject.quote(val.trim());
will qoute all needed values as it says:
Produce a string in double quotes with backslash sequences in all the right places

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