Revert "[SPARK-4075] [Deploy] Jar url validation is not enough for Jar file"

This reverts commit 098f83c7.

core/src/main/scala/org/apache/spark/deploy/ClientArguments.scala

@@ -17,8 +17,6 @@
 
 package org.apache.spark.deploy
 
-import java.net.{URI, URISyntaxException}
-
 import scala.collection.mutable.ListBuffer
 
 import org.apache.log4j.Level
@@ -116,12 +114,5 @@ private[spark] class ClientArguments(args: Array[String]) {
 }
 
 object ClientArguments {
-  def isValidJarUrl(s: String): Boolean = {
-    try {
-      val uri = new URI(s)
-      uri.getScheme != null && uri.getAuthority != null && s.endsWith("jar")
-    } catch {
-      case _: URISyntaxException => false
-    }
-  }
+  def isValidJarUrl(s: String): Boolean = s.matches("(.+):(.+)jar")
 }

core/src/test/scala/org/apache/spark/deploy/ClientSuite.scala

@@ -29,12 +29,6 @@ class ClientSuite extends FunSuite with Matchers {
     ClientArguments.isValidJarUrl("hdfs://someHost:1234/foo") should be (false)
     ClientArguments.isValidJarUrl("/missing/a/protocol/jarfile.jar") should be (false)
     ClientArguments.isValidJarUrl("not-even-a-path.jar") should be (false)
-
-    // No authority
-    ClientArguments.isValidJarUrl("hdfs:someHost:1234/jarfile.jar") should be (false)
-
-    // Invalid syntax
-    ClientArguments.isValidJarUrl("hdfs:") should be (false)
   }
 
 }