Java/Kotlin URLEncoder与Python urlencode输出不一致问题求助

I get it—your current Kotlin approach is encoding the entire parameter string as a single value, which is why you're seeing mismatches with Python's output: the = and & separators are getting encoded, and the * isn't being handled the same way as in Python. Let's fix this to produce an identical URL-encoded string.

The Root of the Difference #

Python's urlencode works by:

1. Taking a list of key-value pairs
2. Encoding each key and value individually
3. Joining them with & (leaving = and & as unencoded separators)
4. Encoding characters like * to %2A

Java/Kotlin's URLEncoder.encode, by contrast, treats the entire input string as a single URL parameter value—so it encodes separators like = and &, and doesn't encode * by default.

The Fix: Encode Key-Value Pairs Individually #

Instead of building the parameter string first and then encoding it, we'll encode each key and value separately, then assemble the final string. We'll also manually handle the * encoding since Java's encoder skips it.

Here's the corrected Kotlin code:

import java.net.URLEncoder
import java.nio.charset.StandardCharsets

fun createVxttokenData(pathUri: String, expiry: Long, reuse: Int, sharedSecret: String) {
    // Match Python's list of key-value pairs structure
    val params = listOf(
        "pathURI" to pathUri,
        "expiry" to expiry.toString(),
        "reuse" to reuse.toString()
    )

    // Encode each key-value pair and join with & separators
    val urlEncodedMessage = params.joinToString("&") { (key, value) ->
        val encodedKey = URLEncoder.encode(key, StandardCharsets.UTF_8.name())
        // Encode value and replace * with %2A to match Python's encoding behavior
        val encodedValue = URLEncoder.encode(value, StandardCharsets.UTF_8.name())
            .replace("*", "%2A")
        "$encodedKey=$encodedValue"
    }

    println(urlEncodedMessage)
    // ... rest of your token generation code
}

fun main() {
    val samplePathUri = "http://my.domain.net/*"
    val sampleExpiry = 1553937508L
    val sampleReuse = 0
    createVxttokenData(samplePathUri, sampleExpiry, sampleReuse, "your-shared-secret")
}

What This Does #

• Individual encoding: By encoding each key and value separately, we ensure = and & are treated as separators (not encoded), just like in Python.
• * handling: We manually replace * with %2A because Java's URLEncoder doesn't encode this character by default, while Python's urlencode does.

Test Output #

Running this code will produce exactly the same string as your Python example:

pathURI=http%3A%2F%2Fmy.domain.net%2F%2A&expiry=1553937508&reuse=0

This should resolve the token authentication failure you're seeing, since the encoded string will now match what Python generates.

内容的提问来源于stack exchange，提问作者Hesam