Identical strings in PHP and Java are not equal

Question

I'm experiencing a strange problem, when I send a String from PHP to Java (Android).

The whole story is rather simple: A Java application sends a keyword to a PHP script. The PHP script looks it up in a DB and sends a JSON encoded array (as a string) back to the Java application.

I can see this string in a TextView field in Android and it looks like this: [{"name":"Berlin"}]

But Java does not accept this as a valid JSON string (unlike some online JSON validators), because it keeps throwing the exception: "A JSONArray text must start with '[' at character 1". When I compare this strings to an identical string hardcoded in Java using "equal()" it turns out, they just aren't equal. And even more disturbing: Java returns the length of the JSON string as 20, not as 19.

Why could this be? There are no unusual characters like Umlauts. What could be the 20th character? I'm suspecting some encoding problem, but I'm pretty sure everything (PHP file, Java file) is UTF-8 encoded.

(Before someone asks: I can provide code, but I don't know which part could be relevant.)

Note it is 'Java' not 'JAVA'. No need to shout it from the rooftops. — Andrew Thompson
– Andrew Thompson, Commented May 8, 2013 at 14:04
Turns out Java has a built in trim() same as php String s = " Hello World ".trim(); — Dave
– Dave, Commented May 8, 2013 at 14:05

Community · Accepted Answer · 2017-05-23 12:13:04Z

1

If the lengths are different there may be differences due to leading/trailing whitespace.

Try looking at this question. The accepted answer provides a way of pre-processing the strings to ensure this problem does not occour.

edited May 23, 2017 at 12:13

CommunityBot

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answered May 8, 2013 at 14:06

Trugath

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1 Comment

Peder Over a year ago

I already tried using trim() without success. But nevertheless the pre-processing idea is something I should have a look at. Thank you!

silkfire · Accepted Answer · 2013-05-08 14:04:58Z

0

Try

int ascii_code = jsonString.codePointAt(0)

and see what you get

answered May 8, 2013 at 14:04

silkfire

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1 Comment

Peder Over a year ago

That's it! It was actually the BOM, but I had no way of making it visible. I spent three days reading JSON-parsing tutorials and questions/answers but that wasn't the problem at all. Thank you!

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