Tweak data.gov query and add postal retries

src/main/kotlin/com/android/trisolarisserver/component/DataGovPincodeClient.kt

@@ -22,14 +22,7 @@ class DataGovPincodeClient(
     fun resolve(pinCode: String): PincodeLookupResult {
         if (apiKey.isBlank()) return PincodeLookupResult(null, null, "NO_API_KEY", "data.gov.in", "Missing API key")
         return try {
-            val first = fetch(pinCode)
-            if (first.resolvedCityState != null) return first
-            val second = fetch("${pinCode}.0")
-            if (second.resolvedCityState != null) return second
-            // Prefer more explicit mismatch status if records exist but don't match pin.
-            if (first.status == "FILTER_MISMATCH") return first
-            if (second.status == "FILTER_MISMATCH") return second
-            first
+            fetch(pinCode)
         } catch (ex: Exception) {
             logger.warn("Data.gov.in lookup failed: {}", ex.message)
             PincodeLookupResult(null, null, "ERROR", "data.gov.in", ex.message)

src/main/kotlin/com/android/trisolarisserver/component/PostalPincodeClient.kt

@@ -3,6 +3,9 @@ package com.android.trisolarisserver.component
 import com.fasterxml.jackson.databind.JsonNode
 import com.fasterxml.jackson.databind.ObjectMapper
 import org.slf4j.LoggerFactory
+import org.springframework.http.HttpEntity
+import org.springframework.http.HttpHeaders
+import org.springframework.http.HttpMethod
 import org.springframework.beans.factory.annotation.Value
 import org.springframework.stereotype.Component
 import org.springframework.web.client.RestTemplate
@@ -34,16 +37,34 @@ class PostalPincodeClient(
             .path("/pincode/{pin}")
             .buildAndExpand(pinCode)
             .toUriString()
-        return try {
-            val response = restTemplate.getForEntity(url, String::class.java)
-            val body = response.body ?: return PincodeLookupResult(null, null, "EMPTY_BODY", "postalpincode.in", requestUrl = url)
-            val resolved = parseCityState(body)
-            val status = if (resolved == null) "ZERO_RESULTS" else "OK"
-            PincodeLookupResult(resolved, body, status, "postalpincode.in", requestUrl = url)
-        } catch (ex: Exception) {
-            logger.warn("Postalpincode lookup failed: {}", ex.message)
-            PincodeLookupResult(null, null, "ERROR", "postalpincode.in", ex.message, url)
+        val headers = HttpHeaders().apply {
+            set("User-Agent", "Mozilla/5.0 (TrisolarisServer)")
+            set("Accept", "application/json")
+            set("Connection", "close")
         }
+        val entity = HttpEntity<Unit>(headers)
+        var lastError: Exception? = null
+        repeat(2) {
+            try {
+                val response = restTemplate.exchange(url, HttpMethod.GET, entity, String::class.java)
+                val body = response.body ?: return PincodeLookupResult(null, null, "EMPTY_BODY", "postalpincode.in", requestUrl = url)
+                val resolved = parseCityState(body)
+                val status = if (resolved == null) "ZERO_RESULTS" else "OK"
+                return PincodeLookupResult(resolved, body, status, "postalpincode.in", requestUrl = url)
+            } catch (ex: Exception) {
+                lastError = ex
+                try {
+                    Thread.sleep(200)
+                } catch (_: InterruptedException) {
+                    Thread.currentThread().interrupt()
+                }
+            }
+        }
+        val errorMessage = lastError?.message
+        if (errorMessage != null) {
+            logger.warn("Postalpincode lookup failed: {}", errorMessage)
+        }
+        return PincodeLookupResult(null, null, "ERROR", "postalpincode.in", errorMessage, url)
     }
 
     private fun parseCityState(body: String): String? {