Thread: Not able to read JSON String from the file which has escape chars

Hi All

I'm facing issue while reading the json string with escape double quote in it which need to be processed by GSON after the extraction. GSON failing with malformed exception as the string conversion not unescaping the \.

File looks like this (first column 12345 is the key separated by tab with the second column json string):
12345 {\"orders\": {\"type\": \"metadata\", \"version\": \"b2f\", \"result\": null},\"saleinfo\": {\"type\": \"metadata\", \"version\": \"1.0\", \"result\": {\"saleinfo\": \"<saleinfo> <NewPositions start=\\\"10\\\" end=\\\"20\\\" /> <OldPositions start=\\\"0\\\" end=\\\"10\\\" /> </saleinfo>\"}}}

I would be getting the record handler in byte array instead of actual file which i converted to string and then split the record into string array with first element of array as key (12345) and second as Json string. But the json string loads with the escape character.

Code below:

byte[] entryData = "file content here in byte array";
String str = new String(entryData); //converting byte array to string
String[] lines = str.split("[\\r\\n]+"); //split into records
 
for(int i=0; i< lines.length; i++) {
	String[] strArray = lines[i].split("\\t");
	String key = strArray[0];
	String jsonStr = new String(strArray[1]);
	System.out.println("JsonString --- "+jsonStr);
	//output is {\"orders\": {\"type\": \"metadata\", \"version\": \"b2f\", \"result\": null},\"saleinfo\": {\"type\": \"metadata\", \"version\": \"1.0\", \"result\": {\"saleinfo\": \"<saleinfo> <NewPositions start=\\\"10\\\" end=\\\"20\\\" />    <OldPositions start=\\\"0\\\" end=\\\"10\\\" />  </saleinfo>\"}}}
	//backslash not escaping
}

Following the above, i would be parsing the jsonStr using GSON (cannot use json parser due to requirement) and extract the tag and its' values. As you see each element is JsonObject..

I got lost on why the unescape not happening converting to string and i cannot use replace due to single and three backslashes in the jsonStr.

Could you please help me in resolving the issue and let me know if you need more info than provided above.

Thanks
kmove

Please edit your post and wrap your code with code tags:

[code]
**YOUR CODE GOES HERE**
[/code]

to get highlighting and preserve formatting.

If you do not want any \ characters in the String, would the String class's replace method work to remove them?

not escaping the backslash.

Can you give a small example of a String that needs to be changed? Not more than one line of characters.
Show the String's contents:
before the change
and after the change
so we can see what you want to do.

There are too many lines for easy comparison. Can you make a smaller sample?

Do these lines show it:
input: {\"saleinfo\": \"<saleinfo> <NewPositions start=\\\"10\\\" end=\\\"20\\\" /> </saleinfo>\"}
output: {"saleinfo": "<saleinfo> <NewPositions start=\"10\" end=\"20\" /> </saleinfo>"}

I do not know if there are packages that will do that. There could be, I have no idea if any exist.

Look what does the compiler does with that line:
System.out.println(
"{\"saleinfo\": \"<saleinfo> <NewPositions start=\\\"10\\\" end=\\\"20\\\" /> </saleinfo>\"}");
// {"saleinfo": "<saleinfo> <NewPositions start=\"10\" end=\"20\" /> </saleinfo>"}


If you want to write your own code, you need to start with a description of what is to be done before trying to write any code.

it prints correctly

That is AFTER the compiler has done the escaping for the \s in the source line.

when i directly read the string from the file

I think what you want is code that works like the compiler.

Take a look at this package: org.apache.commons.text.StringEscapeUtils