Fix #19 Not working with Scala 2.12 processes

Author: ngocdaothanh

README.md

@@ -1,60 +1,61 @@
+# Scalive
+
 This tool allows you to connect a Scala REPL console to running Oracle (Sun)
 JVM processes without any prior setup at the target process.
 
 [![View demo video on YouTube](http://img.youtube.com/vi/h45QQ45D9P8/0.jpg)](http://www.youtube.com/watch?v=h45QQ45D9P8)
 
 ## Download
 
-Download and extract
+For Scala 2.12, download
+[scalive-1.7.0.zip](https://github.com/xitrum-framework/scalive/releases/download/1.7.0/scalive-1.7.0.zip).
+
+For Scala 2.10 and 2.11, download
 [scalive-1.6.zip](https://github.com/xitrum-framework/scalive/releases/download/1.6/scalive-1.6.zip),
-you will see:
 
-```
-scalive-1.6/
-  scalive
-  scalive.cmd
-  scalive-1.6.jar
-  jline-2.14.2.jar
+Extract the ZIP file, you will see:
 
-  scala-library-2.10.6.jar
-  scala-compiler-2.10.6.jar
-  scala-reflect-2.10.6.jar
+```txt
+scalive-1.7.0/
+  scalive
+  scalive.bat
+  scalive-1.7.0.jar
 
-  scala-library-2.11.8.jar
-  scala-compiler-2.11.8.jar
-  scala-reflect-2.11.8.jar
+  scala-library-2.12.8.jar
+  scala-compiler-2.12.8.jar
+  scala-reflect-2.12.8.jar
 ```
 
 scala-library, scala-compiler, and scala-reflect of the correct version
-that your JVM process is using will be loaded, if they have not been loaded.
+that your JVM process is using will be loaded, if they have not been loaded yet.
 The REPL console needs these libraries to work.
 
-For example, your process has already loaded scala-library 2.11.8 by itself,
+For example, your process has already loaded scala-library 2.12.8 by itself,
 but scala-compiler and scala-reflect haven't been loaded, Scalive will
-automatically load their version 2.11.8.
+automatically load their version 2.12.8.
 
 If none of them has been loaded, i.e. your process doesn't use Scala,
 Scalive will load the lastest version in the directory.
 
-For your convenience, Scala 2.10.6 and 2.11.8 JARs are included above.
+For your convenience, Scala 2.12.8 JAR files have been included above.
 
-If your process is using a different Scala version, you need to manually
+If your process uses a different Scala version, you need to manually
 download the corresponding JARs from the Internet and save them in the
 same directory as above.
 
 ## Usage
 
-Run the shell script `scalive` (*nix) or `scalive.cmd` (Windows).
+Run the shell script `scalive` (*nix) or `scalive.bat` (Windows).
 
 Run without argument to see the list of running JVM process IDs on your local machine:
 
-```
+```sh
 scalive
 ```
 
 Example output:
 
-```
+```txt
 JVM processes:
 #pid	Display name
 13821	demos.Boot
@@ -63,7 +64,7 @@ JVM processes:
 
 To connect a Scala REPL console to a process:
 
-```
+```sh
 scalive <process id listed above>
 ```
 
@@ -80,7 +81,7 @@ Scalive only automatically loads `scala-library.jar`, `scala-compiler.jar`,
 If you want to load additional classes in other JARs, first run these in the
 REPL console to load the JAR to the system class loader:
 
-```
+```scala
 val cl            = ClassLoader.getSystemClassLoader.asInstanceOf[java.net.URLClassLoader]
 val jarSearchDirs = Array("/dir/containing/the/jar")
 val jarPrefix     = "mylib"  // Will match "mylib-xxx.jar", convenient when there's version number in the file name
@@ -90,7 +91,7 @@ scalive.Classpath.findAndAddJar(cl, jarSearchDirs, jarPrefix)
 Now the trick is just quit the REPL console and connect it to the target process
 again. You will be able to use your classes in the JAR normally:
 
-```
+```scala
 import mylib.foo.Bar
 ...
 ```
@@ -99,13 +100,13 @@ import mylib.foo.Bar
 
 ## How Scalive works
 
-Scalive uses the [Attach API](https://blogs.oracle.com/CoreJavaTechTips/entry/the_attach_api) in Java 6
+Scalive uses the [Attach API](https://blogs.oracle.com/CoreJavaTechTips/entry/the_attach_api)
 to tell the target process to load an [agent](http://javahowto.blogspot.jp/2006/07/javaagent-option.html).
 
 Inside the target progress, the agent creates a REPL interpreter and a
 TCP server to let the Scalive process connect and interact with the
 interpreter. The Scalive process acts as a TCP client. There are 2 TCP
-connections, one for REPL data and one for completion data.
+connections, one for REPL data and one for tab key completion data.
 
 Similar projects:
 
@@ -118,7 +119,7 @@ For simplicity and to avoid memory leak when you attach/detach many times,
 Scalive only supports processes with only the default system class loader,
 without additional class loaders. Usually they are standalone JVM processes,
 like
-[Play](http://www.playframework.com/) or
-[Xitrum](http://xitrum-framework.github.io/) in production mode.
+[Play](http://www.playframework.com) or
+[Xitrum](http://xitrum-framework.github.io) in production mode.
 
 Processes with multiple class loaders like Tomcat are currently not supported.

build.sbt

@@ -1,19 +1,20 @@
 organization := "tv.cntt"
 name         := "scalive"
-version      := "1.6"
+version      := "1.7.0"
 
-scalaVersion     := "2.11.8"
+// Scalive is a Java library, we only use SBT to build
+scalaVersion     := "2.12.8"
 autoScalaLibrary := false
 crossPaths       := false  // Do not append Scala versions to the generated artifacts
 
 javacOptions ++= Seq("-Xlint:deprecation")
 
-// Ensure Scalive can run on Java 6
-scalacOptions += "-target:jvm-1.6"
-javacOptions ++= Seq("-source", "1.6", "-target", "1.6")
+// Ensure Scalive can run on Java from 8 (Scala 2.12 requires Java 8)
+scalacOptions += "-target:jvm-1.8"
+javacOptions ++= Seq("-source", "1.8", "-target", "1.8")
 
+// scala-compiler already embeds JLine, no need to add JLine dependency separately
 libraryDependencies += "org.scala-lang" % "scala-compiler" % scalaVersion.value % "provided"
-libraryDependencies += "jline"          % "jline"          % "2.14.2"
 
 // Add tools.jar to classpath
 // https://blogs.oracle.com/CoreJavaTechTips/entry/the_attach_api

dev/README.rst

@@ -24,17 +24,12 @@ This is the directory that will be zipped when Scalive is released.
 
   zip/
     scalive
-    scalive.cmd
+    scalive.bat
     scalive-<version>.jar <- ../../target/scala-2.11/scalive-<version>.jar
-    jline-2.14.2.jar      <- Download and put JLine JAR here
 
-    scala-library-2.10.6.jar
-    scala-compiler-2.10..jar
-    scala-reflect-2.10.6.jar
-
-    scala-library-2.11.8.jar
-    scala-compiler-2.11.8.jar
-    scala-reflect-2.11.8.jar
+    scala-library-2.12.8.jar
+    scala-compiler-2.12.8.jar
+    scala-reflect-2.12.8.jar
 
 While developing:
 
@@ -46,22 +41,20 @@ Release
 -------
 
 Based on the ``zip`` directory above, prepare a directory to be zipped and
-released (remember to remove uneccessary files, like .gitignore):
+released (remember to remove unneccessary files, like .gitignore):
 
 ::
 
   scalive-<version>/
     scalive
-    scalive.cmd
+    scalive.bat
     scalive-<version>.jar  <- Doesn't depend on Scala, thus doesn't follow Scala JAR naming
 
-    scala-library-2.10.4.jar
-    scala-compiler-2.10.4.jar
-    scala-reflect-2.10.4.jar
+    scala-library-2.12.8.jar
+    scala-compiler-2.12.8.jar
+    scala-reflect-2.12.8.jar
 
-    scala-library-2.11.4.jar
-    scala-compiler-2.11.4.jar
-    scala-reflect-2.11.4.jar
+    README.md
 
 Then zip it:
 

dev/zip/scalive.cmd renamed to dev/zip/scalive.bat

@@ -1 +1 @@
-sbt.version=0.13.12
+sbt.version=1.2.8

project/build.properties

@@ -1,2 +1,2 @@
-// Run sbt eclipse to create Eclipse project file
-addSbtPlugin("com.typesafe.sbteclipse" % "sbteclipse-plugin" % "4.0.0")
+// Run "sbt eclipse" to create Eclipse project file
+addSbtPlugin("com.typesafe.sbteclipse" % "sbteclipse-plugin" % "5.2.4")

project/plugins.sbt

@@ -7,6 +7,8 @@
 import java.net.URL;
 import java.net.URLClassLoader;
 import java.util.Arrays;
+import java.util.Objects;
+import java.util.stream.Collectors;
 
 public class Classpath {
     private static final Method addURL = getAddURL();
@@ -51,7 +53,7 @@ public static String findJar(String[] jarSearchDirs, String jarPrefix) throws Il
         }
 
         if (maxFile == null)
-            throw new IllegalStateException("Could not find " + jarPrefix + " in " + join(jarSearchDirs, File.pathSeparator));
+            throw new IllegalStateException("Could not find " + jarPrefix + " in " + String.join(File.pathSeparator, jarSearchDirs));
         else
             return maxFile.getPath();
     }
@@ -78,7 +80,7 @@ public static void findAndAddJar(
      * but only find and add the JAR to classpath if the representativeClass has not been loaded.
      */
     public static void findAndAddJar(
-        URLClassLoader cl, String representativeClass, String[] jarSearchDirs, String jarPrefix
+            URLClassLoader cl, String representativeClass, String[] jarSearchDirs, String jarPrefix
     ) throws IllegalAccessException, MalformedURLException, InvocationTargetException {
         try {
             Class.forName(representativeClass, true, cl);
@@ -90,7 +92,7 @@ public static void findAndAddJar(
     // http://stackoverflow.com/questions/4121567/embedded-scala-repl-inherits-parent-classpath
     public static String getClasspath(URLClassLoader cl) {
         URL[] urls = cl.getURLs();
-        return join(urls, File.pathSeparator);
+        return Arrays.stream(urls).map(Objects::toString).collect(Collectors.joining(File.pathSeparator));
     }
 
     public static String getScalaVersion(
@@ -100,15 +102,4 @@ public static String getScalaVersion(
         Method   m = k.getDeclaredMethod("versionNumberString");
         return (String) m.invoke(k);
     }
-
-    //--------------------------------------------------------------------------
-
-    private static String join(Object[] xs, String separator) {
-        StringBuilder b = new StringBuilder();
-        for (Object x: xs) {
-            if (b.length() > 0) b.append(separator);
-            b.append(x);
-        }
-        return b.toString();
-    }
 }

src/main/java/scalive/Classpath.java

@@ -36,15 +36,12 @@ public static void throwSocketTimeoutExceptionForLongInactivity(Socket socket) t
      * The sockets are closed in the order they are given.
      */
     public static Runnable getSocketCleaner(final Socket... sockets) {
-        return new Runnable() {
-            @Override
-            public void run() {
-                for (Socket socket : sockets) {
-                    try {
-                        socket.close();
-                    } catch (IOException e) {
-                        // Ignore
-                    }
+        return () -> {
+            for (Socket socket : sockets) {
+                try {
+                    socket.close();
+                } catch (IOException e) {
+                    // Ignore
                 }
             }
         };

src/main/java/scalive/Net.java

@@ -1,6 +1,6 @@
 package scalive.client;
 
-import jline.console.ConsoleReader;
+import scala.tools.jline_embedded.console.ConsoleReader;
 
 import scalive.Log;
 import scalive.Net;
@@ -23,7 +23,7 @@ public void run() {
         });
 
         ConsoleReader reader = new ConsoleReader(System.in, System.out);
-        Completer.setup(completerSocket, reader);
-        Repl.run(replSocket, reader);
+        ClientCompleter.setup(completerSocket, reader);
+        ClientRepl.run(replSocket, reader);
     }
 }

src/main/java/scalive/client/Client.java

@@ -0,0 +1,51 @@
+package scalive.client;
+
+import scala.tools.jline_embedded.console.ConsoleReader;
+
+import java.io.BufferedReader;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.OutputStream;
+import java.net.Socket;
+import java.nio.charset.StandardCharsets;
+import java.util.List;
+
+/**
+ * Input: cursor buffer
+ *
+ * Output: cursor candidate1 candidate2 candidate3...
+ */
+class ClientCompleter {
+    static void setup(Socket socket, ConsoleReader reader) throws Exception {
+        final InputStream in  = socket.getInputStream();
+        final OutputStream out = socket.getOutputStream();
+
+        final BufferedReader b = new BufferedReader(new InputStreamReader(in, StandardCharsets.UTF_8));
+
+        reader.addCompleter((String buffer, int cursor, List<CharSequence> candidates) -> {
+            try {
+                String request = String.format("%d %s\n", cursor, buffer);
+                out.write(request.getBytes(StandardCharsets.UTF_8));
+                out.flush();
+
+                String response = b.readLine();
+
+                // socket closed; the client should exit
+                if (response == null) return -1;
+
+                String[] args = response.split(" ");
+
+                int c = Integer.parseInt(args[0]);
+
+                for (int i = 1; i < args.length; i++) {
+                    String candidate = args[i];
+                    candidates.add(candidate);
+                }
+
+                return c;
+            } catch (Exception e) {
+                throw new RuntimeException(e);
+            }
+        });
+    }
+}