SPARK-1078: Replace lift-json with json4s-jackson.

The aim of the Json4s project is to provide a common API for
Scala JSON libraries.  It is Apache-licensed, easier for
downstream distributions to package, and mostly API-compatible
with lift-json.  Furthermore, the Jackson-backed implementation
parses faster than lift-json on all but the smallest inputs.

Author: William Benton <willb@redhat.com>

Closes #582 from willb/json4s and squashes the following commits:

7ca62c4 [William Benton] Replace lift-json with json4s-jackson.

9 files changed, 32 insertions, 24 deletions

diff --git a/core/pom.xml b/core/pom.xml
index f209704f31..ebc178a105 100644
--- a/core/pom.xml
+++ b/core/pom.xml
@@ -130,8 +130,9 @@
             <artifactId>scala-library</artifactId>
         </dependency>
         <dependency>
-            <groupId>net.liftweb</groupId>
-            <artifactId>lift-json_${scala.binary.version}</artifactId>
+            <groupId>org.json4s</groupId>
+            <artifactId>json4s-jackson_${scala.binary.version}</artifactId>
+            <version>3.2.6</version>
         </dependency>
         <dependency>
             <groupId>it.unimi.dsi</groupId>
diff --git a/core/src/main/scala/org/apache/spark/deploy/FaultToleranceTest.scala b/core/src/main/scala/org/apache/spark/deploy/FaultToleranceTest.scala
index 190b331cfe..d48c1892ae 100644
--- a/core/src/main/scala/org/apache/spark/deploy/FaultToleranceTest.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/FaultToleranceTest.scala
@@ -27,7 +27,8 @@ import scala.concurrent.ExecutionContext.Implicits.global
 import scala.concurrent.duration._
 import scala.sys.process._
 
-import net.liftweb.json.JsonParser
+import org.json4s._
+import org.json4s.jackson.JsonMethods
 
 import org.apache.spark.{Logging, SparkContext}
 import org.apache.spark.deploy.master.RecoveryState
@@ -311,7 +312,7 @@ private[spark] object FaultToleranceTest extends App with Logging {
 private[spark] class TestMasterInfo(val ip: String, val dockerId: DockerId, val logFile: File)
   extends Logging  {
 
-  implicit val formats = net.liftweb.json.DefaultFormats
+  implicit val formats = org.json4s.DefaultFormats
   var state: RecoveryState.Value = _
   var liveWorkerIPs: List[String] = _
   var numLiveApps = 0
@@ -321,7 +322,7 @@ private[spark] class TestMasterInfo(val ip: String, val dockerId: DockerId, val
   def readState() {
     try {
       val masterStream = new InputStreamReader(new URL("http://%s:8080/json".format(ip)).openStream)
-      val json = JsonParser.parse(masterStream, closeAutomatically = true)
+      val json = JsonMethods.parse(masterStream)
 
       val workers = json \ "workers"
       val liveWorkers = workers.children.filter(w => (w \ "state").extract[String] == "ALIVE")
@@ -349,7 +350,7 @@ private[spark] class TestMasterInfo(val ip: String, val dockerId: DockerId, val
 private[spark] class TestWorkerInfo(val ip: String, val dockerId: DockerId, val logFile: File)
   extends Logging {
 
-  implicit val formats = net.liftweb.json.DefaultFormats
+  implicit val formats = org.json4s.DefaultFormats
 
   logDebug("Created worker: " + this)
 
diff --git a/core/src/main/scala/org/apache/spark/deploy/JsonProtocol.scala b/core/src/main/scala/org/apache/spark/deploy/JsonProtocol.scala
index 318beb5db5..cefb1ff97e 100644
--- a/core/src/main/scala/org/apache/spark/deploy/JsonProtocol.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/JsonProtocol.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.deploy
 
-import net.liftweb.json.JsonDSL._
+import org.json4s.JsonDSL._
 
 import org.apache.spark.deploy.DeployMessages.{MasterStateResponse, WorkerStateResponse}
 import org.apache.spark.deploy.master.{ApplicationInfo, DriverInfo, WorkerInfo}
diff --git a/core/src/main/scala/org/apache/spark/deploy/master/ui/ApplicationPage.scala b/core/src/main/scala/org/apache/spark/deploy/master/ui/ApplicationPage.scala
index 5cc4adbe44..90cad3c37f 100644
--- a/core/src/main/scala/org/apache/spark/deploy/master/ui/ApplicationPage.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/master/ui/ApplicationPage.scala
@@ -23,7 +23,8 @@ import scala.concurrent.Await
 import scala.xml.Node
 
 import akka.pattern.ask
-import net.liftweb.json.JsonAST.JValue
+import javax.servlet.http.HttpServletRequest
+import org.json4s.JValue
 
 import org.apache.spark.deploy.JsonProtocol
 import org.apache.spark.deploy.DeployMessages.{MasterStateResponse, RequestMasterState}
diff --git a/core/src/main/scala/org/apache/spark/deploy/master/ui/IndexPage.scala b/core/src/main/scala/org/apache/spark/deploy/master/ui/IndexPage.scala
index 01c8f9065e..bac922bcd3 100644
--- a/core/src/main/scala/org/apache/spark/deploy/master/ui/IndexPage.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/master/ui/IndexPage.scala
@@ -23,7 +23,8 @@ import scala.concurrent.Await
 import scala.xml.Node
 
 import akka.pattern.ask
-import net.liftweb.json.JsonAST.JValue
+import javax.servlet.http.HttpServletRequest
+import org.json4s.JValue
 
 import org.apache.spark.deploy.{DeployWebUI, JsonProtocol}
 import org.apache.spark.deploy.DeployMessages.{MasterStateResponse, RequestMasterState}
diff --git a/core/src/main/scala/org/apache/spark/deploy/worker/ui/IndexPage.scala b/core/src/main/scala/org/apache/spark/deploy/worker/ui/IndexPage.scala
index 3089acffb8..85200ab0e1 100644
--- a/core/src/main/scala/org/apache/spark/deploy/worker/ui/IndexPage.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/worker/ui/IndexPage.scala
@@ -22,7 +22,7 @@ import scala.xml.Node
 
 import akka.pattern.ask
 import javax.servlet.http.HttpServletRequest
-import net.liftweb.json.JsonAST.JValue
+import org.json4s.JValue
 
 import org.apache.spark.deploy.JsonProtocol
 import org.apache.spark.deploy.DeployMessages.{RequestWorkerState, WorkerStateResponse}
diff --git a/core/src/main/scala/org/apache/spark/ui/JettyUtils.scala b/core/src/main/scala/org/apache/spark/ui/JettyUtils.scala
index 1f048a84cd..1b78c52ff6 100644
--- a/core/src/main/scala/org/apache/spark/ui/JettyUtils.scala
+++ b/core/src/main/scala/org/apache/spark/ui/JettyUtils.scala
@@ -24,7 +24,8 @@ import scala.annotation.tailrec
 import scala.util.{Failure, Success, Try}
 import scala.xml.Node
 
-import net.liftweb.json.{JValue, pretty, render}
+import org.json4s.JValue
+import org.json4s.jackson.JsonMethods.{pretty, render}
 import org.eclipse.jetty.server.{Handler, Request, Server}
 import org.eclipse.jetty.server.handler.{AbstractHandler, ContextHandler, HandlerList, ResourceHandler}
 import org.eclipse.jetty.util.thread.QueuedThreadPool
diff --git a/core/src/test/scala/org/apache/spark/deploy/JsonProtocolSuite.scala b/core/src/test/scala/org/apache/spark/deploy/JsonProtocolSuite.scala
index de866ed7ff..bae3b37e26 100644
--- a/core/src/test/scala/org/apache/spark/deploy/JsonProtocolSuite.scala
+++ b/core/src/test/scala/org/apache/spark/deploy/JsonProtocolSuite.scala
@@ -20,9 +20,12 @@ package org.apache.spark.deploy
 import java.io.File
 import java.util.Date
 
-import net.liftweb.json.Diff
-import net.liftweb.json.{JsonAST, JsonParser}
-import net.liftweb.json.JsonAST.{JNothing, JValue}
+import org.json4s._
+
+import org.json4s.JValue
+import org.json4s.jackson.JsonMethods
+import com.fasterxml.jackson.core.JsonParseException
+
 import org.scalatest.FunSuite
 
 import org.apache.spark.deploy.DeployMessages.{MasterStateResponse, WorkerStateResponse}
@@ -34,31 +37,31 @@ class JsonProtocolSuite extends FunSuite {
   test("writeApplicationInfo") {
     val output = JsonProtocol.writeApplicationInfo(createAppInfo())
     assertValidJson(output)
-    assertValidDataInJson(output, JsonParser.parse(JsonConstants.appInfoJsonStr))
+    assertValidDataInJson(output, JsonMethods.parse(JsonConstants.appInfoJsonStr))
   }
 
   test("writeWorkerInfo") {
     val output = JsonProtocol.writeWorkerInfo(createWorkerInfo())
     assertValidJson(output)
-    assertValidDataInJson(output, JsonParser.parse(JsonConstants.workerInfoJsonStr))
+    assertValidDataInJson(output, JsonMethods.parse(JsonConstants.workerInfoJsonStr))
   }
 
   test("writeApplicationDescription") {
     val output = JsonProtocol.writeApplicationDescription(createAppDesc())
     assertValidJson(output)
-    assertValidDataInJson(output, JsonParser.parse(JsonConstants.appDescJsonStr))
+    assertValidDataInJson(output, JsonMethods.parse(JsonConstants.appDescJsonStr))
   }
 
   test("writeExecutorRunner") {
     val output = JsonProtocol.writeExecutorRunner(createExecutorRunner())
     assertValidJson(output)
-    assertValidDataInJson(output, JsonParser.parse(JsonConstants.executorRunnerJsonStr))
+    assertValidDataInJson(output, JsonMethods.parse(JsonConstants.executorRunnerJsonStr))
   }
 
   test("writeDriverInfo") {
     val output = JsonProtocol.writeDriverInfo(createDriverInfo())
     assertValidJson(output)
-    assertValidDataInJson(output, JsonParser.parse(JsonConstants.driverInfoJsonStr))
+    assertValidDataInJson(output, JsonMethods.parse(JsonConstants.driverInfoJsonStr))
   }
 
   test("writeMasterState") {
@@ -71,7 +74,7 @@ class JsonProtocolSuite extends FunSuite {
       activeDrivers, completedDrivers, RecoveryState.ALIVE)
     val output = JsonProtocol.writeMasterState(stateResponse)
     assertValidJson(output)
-    assertValidDataInJson(output, JsonParser.parse(JsonConstants.masterStateJsonStr))
+    assertValidDataInJson(output, JsonMethods.parse(JsonConstants.masterStateJsonStr))
   }
 
   test("writeWorkerState") {
@@ -83,7 +86,7 @@ class JsonProtocolSuite extends FunSuite {
       finishedExecutors, drivers, finishedDrivers, "masterUrl", 4, 1234, 4, 1234, "masterWebUiUrl")
     val output = JsonProtocol.writeWorkerState(stateResponse)
     assertValidJson(output)
-    assertValidDataInJson(output, JsonParser.parse(JsonConstants.workerStateJsonStr))
+    assertValidDataInJson(output, JsonMethods.parse(JsonConstants.workerStateJsonStr))
   }
 
   def createAppDesc(): ApplicationDescription = {
@@ -125,9 +128,9 @@ class JsonProtocolSuite extends FunSuite {
 
   def assertValidJson(json: JValue) {
     try {
-      JsonParser.parse(JsonAST.compactRender(json))
+      JsonMethods.parse(JsonMethods.compact(json))
     } catch {
-      case e: JsonParser.ParseException => fail("Invalid Json detected", e)
+      case e: JsonParseException => fail("Invalid Json detected", e)
     }
   }
 
diff --git a/project/SparkBuild.scala b/project/SparkBuild.scala
index 220894affb..7d157160d1 100644
--- a/project/SparkBuild.scala
+++ b/project/SparkBuild.scala
@@ -268,7 +268,7 @@ object SparkBuild extends Build {
         "org.spark-project.akka"  %% "akka-remote"      % "2.2.3-shaded-protobuf"  excludeAll(excludeNetty),
         "org.spark-project.akka"  %% "akka-slf4j"       % "2.2.3-shaded-protobuf"  excludeAll(excludeNetty),
         "org.spark-project.akka"  %% "akka-testkit"     % "2.2.3-shaded-protobuf" % "test",
-        "net.liftweb"             %% "lift-json"        % "2.5.1"  excludeAll(excludeNetty),
+        "org.json4s"              %% "json4s-jackson"   % "3.2.6",
         "it.unimi.dsi"             % "fastutil"         % "6.4.4",
         "colt"                     % "colt"             % "1.2.0",
         "org.apache.mesos"         % "mesos"            % "0.13.0",