changing to require instead of if

sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/jdbc/JDBCRDD.scala

@@ -54,7 +54,6 @@ object JDBCRDD extends Logging {
     val table = options.tableOrQuery
     val dialect = JdbcDialects.get(url)
     val conn: Connection = JdbcUtils.createConnectionFactory(options)()
-
     try {
       val statement = conn.prepareStatement(dialect.getSchemaQuery(table))
       try {

sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/jdbc/JdbcUtils.scala

@@ -62,10 +62,8 @@ object JdbcUtils extends Logging {
           s"Did not find registered driver with class $driverClass")
       }
       val connection: Connection = driver.connect(options.url, options.asConnectionProperties)
-
-      if (connection == null) {
-        throw new IllegalArgumentException("Wrong url in JDBC options.")
-      }
+      require(connection != null,
+        s"The driver could not open a JDBC connection. Check the URL: ${options.url}")
 
       connection
     }

sql/core/src/test/scala/org/apache/spark/sql/jdbc/JDBCSuite.scala

@@ -1509,7 +1509,7 @@ class JDBCSuite extends QueryTest
       Row("fred", 1) :: Nil)
   }
 
-  test("SPARK-26383 throw IllegalArgumentException if url is wrong") {
+  test("SPARK-26383 throw IllegalArgumentException if wrong kind of driver to the given url") {
     val e = intercept[IllegalArgumentException] {
       val opts = Map(
         "url" -> "jdbc:mysql://localhost/db",
@@ -1518,6 +1518,7 @@ class JDBCSuite extends QueryTest
       )
       spark.read.format("jdbc").options(opts).load
     }.getMessage
-    assert(e.contains("Wrong url in JDBC options."))
+    assert(e.contains("The driver could not open a JDBC connection. " +
+      "Check the URL: jdbc:mysql://localhost/db"))
   }
 }