Implemented IsgdException. Closes #1

src/main/kotlin/net/thauvin/erik/isgd/Isgd.kt

@@ -38,7 +38,7 @@ import java.net.URLEncoder
 import java.nio.charset.StandardCharsets
 
 /**
- * See the [is.gd API](https://is.gd/apishorteningreference.php)
+ * See the [is.gd API](https://is.gd/apishorteningreference.php).
  */
 enum class Format(val type: String) {
     WEB("web"), SIMPLE("simple"), XML("xml"), JSON("json")
@@ -48,18 +48,25 @@ fun String.encode(): String {
     return URLEncoder.encode(this, StandardCharsets.UTF_8.name())
 }
 
+/**
+ * Implements the [is.gd API](https://is.gd/developers.php).
+ */
 class Isgd private constructor() {
     companion object {
         private fun callApi(url: String): String {
             val connection = URL(url).openConnection() as HttpURLConnection
             connection.setRequestProperty(
                 "User-Agent",
-                "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:75.0) Gecko/20100101 Firefox/75.0"
+                "Mozilla/5.0 (Linux x86_64; rv:89.0) Gecko/20100101 Firefox/89.0"
             )
-            return connection.inputStream.bufferedReader().readText()
+            if (connection.responseCode in 200..399) {
+                return connection.inputStream.bufferedReader().readText()
+            } else {
+                throw IsgdException(connection.responseCode, connection.errorStream.bufferedReader().readText())
+            }
         }
 
-        private fun host(isVgd: Boolean = false): String {
+        private fun getHost(isVgd: Boolean = false): String {
             return if (isVgd) "v.gd" else "is.gd"
         }
 
@@ -68,6 +75,7 @@ class Isgd private constructor() {
          */
         @JvmStatic
         @JvmOverloads
+        @Throws(IsgdException::class)
         fun lookup(
             shorturl: String,
             callback: String = "",
@@ -78,7 +86,7 @@ class Isgd private constructor() {
                 throw IllegalArgumentException("Please specify a valid short URL to lookup.")
             }
 
-            val sb = StringBuilder("https://${host(isVgd)}/forward.php?shorturl=${shorturl.encode()}")
+            val sb = StringBuilder("https://${getHost(isVgd)}/forward.php?shorturl=${shorturl.encode()}")
 
             if (callback.isNotEmpty()) {
                 sb.append("&callback=${callback.encode()}")
@@ -94,6 +102,7 @@ class Isgd private constructor() {
          */
         @JvmStatic
         @JvmOverloads
+        @Throws(IsgdException::class)
         fun shorten(
             url: String,
             shorturl: String = "",
@@ -106,7 +115,7 @@ class Isgd private constructor() {
                 throw IllegalArgumentException("Please enter a valid URL to shorten.")
             }
 
-            val sb = StringBuilder("https://${host(isVgd)}/create.php?url=${url.encode()}")
+            val sb = StringBuilder("https://${getHost(isVgd)}/create.php?url=${url.encode()}")
 
             if (shorturl.isNotEmpty()) {
                 sb.append("&shorturl=${shorturl.encode()}")

src/main/kotlin/net/thauvin/erik/isgd/IsgdException.kt

@@ -0,0 +1,45 @@
+/*
+ * IsgdException.kt
+ *
+ * Copyright (c) 2020-2021, Erik C. Thauvin (erik@thauvin.net)
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   Redistributions of source code must retain the above copyright notice, this
+ *   list of conditions and the following disclaimer.
+ *
+ *   Redistributions in binary form must reproduce the above copyright notice,
+ *   this list of conditions and the following disclaimer in the documentation
+ *   and/or other materials provided with the distribution.
+ *
+ *   Neither the name of this project nor the names of its contributors may be
+ *   used to endorse or promote products derived from this software without
+ *   specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package net.thauvin.erik.isgd
+
+/**
+ * Thrown when an exceptional condition has occurred.
+ *
+ * @property statusCode The HTTP status code.
+ * @property message The error message.
+ */
+class IsgdException(val statusCode: Int, message: String) : Exception(message) {
+    companion object {
+        private const val serialVersionUID = 1L
+    }
+}

src/test/kotlin/net/thauvin/erik/isgd/IsgdTest.kt

@@ -34,6 +34,7 @@ package net.thauvin.erik.isgd
 
 import kotlin.test.Test
 import kotlin.test.assertEquals
+import kotlin.test.assertFailsWith
 import kotlin.test.assertTrue
 
 class IsgdTest {
@@ -41,6 +42,21 @@ class IsgdTest {
     private val shortUrl = "https://is.gd/Pt2sET"
     private val shortVgdUrl = "https://v.gd/2z2ncj"
 
+    @Test
+    fun testException() {
+        assertFailsWith(
+            message = "URL is already shorten",
+            exceptionClass = IsgdException::class,
+            block = { Isgd.shorten(shortUrl) }
+        )
+
+        try {
+            Isgd.shorten(shortUrl)
+        } catch (e: IsgdException) {
+            assertTrue(e.statusCode == 400, "status code == 400")
+        }
+    }
+
     @Test
     fun testLookupDefault() {
         assertEquals(url, Isgd.lookup(shortUrl))