改装Android-拦截所有请求GET/PUT/POST/DELETE

Question

向所有开发人员致以问候。我有一个应用程序，它已经在playstore上发布，并使用改装作为网络接口。现在，我遇到了一个要求，即无论请求是GET/PUT/POST/DELETE，我都必须在通过应用程序的所有请求中发送一个参数。在GET/PUT/DELETE的情况下，我会发送额外的param作为查询param，但在POST中，我会将其添加到正文中。参见下面的代码-

class CommonParamsInterceptor : Interceptor {
companion object {
const val EXTRA_PARAM = "extra_param"
}
override fun intercept(chain: Interceptor.Chain): Response {
val request = chain.request()
return chain.proceed(
when (request.method()) {
HTTP_METHOD_GET, HTTP_METHOD_PUT, HTTP_METHOD_DELETE -> {
val url = request.url()
request.newBuilder()
.url(
url.newBuilder()
.addQueryParameter(EXTRA_PARAM, "param_value")
.build()
)
.build()
}
HTTP_METHOD_POST -> {
val body = request.body()
request.newBuilder()
.post(
RequestBody.create(
body?.contentType(),
body.bodyToString() + "&" + EXTRA_PARAM + "=" + "param_value"
)
)
.build()
}
else -> request
}
)
}
}


private fun RequestBody?.bodyToString(): String {
if (this == null) return ""
val buffer = okio.Buffer()
writeTo(buffer)
return buffer.readUtf8()
}

现在的问题是，我的一些帖子请求可能没有正文，也可能有Map，或者可能有json作为内容那么，如何在所有帖子请求中添加PARAM，而不考虑正文类型？。提前谢谢

Answer 1

为了将来参考，发布我的解决方案版本。

class CommonParamsInterceptor : Interceptor {
companion object {
const val PARAM_EXTRA = "extra_param"
const val TYPE_FORM = "form"
const val TYPE_JSON = "json"
}
override fun intercept(chain: Interceptor.Chain): Response {
val request = chain.request()
return  chain.proceed(
when (request.method()) {
HTTP_METHOD_GET, HTTP_METHOD_PUT, HTTP_METHOD_DELETE -> {
val url = request.url()
request.newBuilder()
.url(
url.newBuilder()
.addQueryParameter(PARAM_EXTRA, "val")
.build()
)
.build()
}
HTTP_METHOD_POST -> {
var requestBody = request.body()
if (requestBody != null) {
val subtype = requestBody.contentType()?.subtype()
if (subtype?.contains(TYPE_JSON) == true) { /* when it is json */
requestBody = processApplicationJsonRequestBody(requestBody)
} else if (subtype?.contains(TYPE_FORM) == true) { /* when it is form-data */
requestBody = processFormDataRequestBody(requestBody)
}
} else { /* when we don't have any body*/
requestBody = FormBody.Builder()
.add(PARAM_EXTRA, "val")
.build()
}
requestBody?.run {
request.newBuilder()
.post(this)
.build()
} ?: kotlin.run {
request
}
}
else -> request
}
)
}
}
private fun bodyToString(request: RequestBody?): String {
if (request == null) return ""
try {
val buffer = okio.Buffer()
request.writeTo(buffer)
return buffer.readUtf8()
} catch (e: Exception) {
MerchantLogger.logAndPrintException(e)
return ""
}
}
private fun processApplicationJsonRequestBody(
requestBody: RequestBody
): RequestBody? {
val customReq = bodyToString(requestBody)
try {
val obj = JSONObject(customReq)
obj.put(PARAM_EXTRA, "val")
return RequestBody.create(requestBody.contentType(), obj.toString())
} catch (e: JSONException) {
e.printStackTrace()
}
return null
}
private fun processFormDataRequestBody(
requestBody: RequestBody
): RequestBody {
val formBody: RequestBody = FormBody.Builder()
.add(PARAM_EXTRA,"val")
.build()
var postBodyString = bodyToString(requestBody)
postBodyString += (if (postBodyString.isEmpty().not()) "&" else "") + bodyToString(formBody)
return RequestBody.create(requestBody.contentType(), postBodyString)
}
}