Add startup options. Improve documentation

Author: mrsarm

README.md

@@ -1,11 +1,18 @@
 JShell Plugin
 =============
 
-This Gradle plugin helps you to explore your code and dependencies in your gradle project
+This **Gradle plugin** helps you to explore your code and dependencies in your gradle project
 with in [jshell](https://docs.oracle.com/javase/9/jshell/introduction-jshell.htm),
 the official Java REPL tool.
 
-Hosted on (NOT published yet): https://plugins.gradle.org/plugin/com.github.mrsarm.jshell.plugin
+Hosted on _(NOT published yet)_: https://plugins.gradle.org/plugin/com.github.mrsarm.jshell.plugin
+
+ - [Getting started](#getting-started)
+ - [Startup options](#startup-options)
+ - [Troubleshooting](#troubleshooting)
+ - [System Requirements](#system-requirements)
+ - [Build and Publish](#build-an-publish)
+ - [About](#about)
 
 
 Getting started
@@ -19,7 +26,7 @@ plugins {
 }
 ```
 
-or for Gradle < 2.1:
+or in Gradle < 2.1:
 
 ```groovy
 buildscript {
@@ -44,14 +51,54 @@ Following is an example:
 
     $ gradle --no-daemon --console plain jshell
 
+Startup options
+---------------
+
+The shell console starts with the options
+`--startup DEFAULT --startup PRINTING` so always
+the following imports and functions are available:
+
+ - java.io
+ - java.math
+ - java.net
+ - java.nio.file
+ - java.util
+ - java.util.concurrent
+ - java.util.function
+ - java.util.prefs
+ - java.util.regex
+ - java.util.stream
+ - print (alias of `System.out.print`)
+ - println (alias of `System.out.println`)
+
+If the plugin founds at the root of the project a
+[JShell Script](https://docs.oracle.com/javase/9/jshell/scripts.htm)
+named `startup.jsh`, it will append to the JShell session
+the argument `--startup startup.jsh`, executing
+at the beginning all the instruction in the script,
+so you can add there all the imports, object definitions
+or any Java instruction that you want to execute
+at the begging of the session. You can override
+the startup script path with the project property
+`jshell.startup` in the `gradle.properties` file,
+or set the same property in the command line
+arguments, like: 
+
+    $ gradle --no-daemon --console plain jshell -Pjshell.startup=/path/to/run.jsh
+
+
+Troubleshooting
+---------------
+
 If you see this warning and the jshell console does not detect your classes:
 
 > :jshell task :classes not found, be sure to compile the project first
 
 Means the `classes` task needed to compile your project before launch `jshell`
-does not exist, just append the task needed to compile the project,
-some times is the same `classes` task but is not detected in multi-modules
-projects, so you need to add it explicitly in the Gradle command:
+does not exist, just append in the command line the task needed to compile
+the project, some times is the same `classes` task but is not detected
+in multi-modules projects, so you need to add it explicitly in the
+Gradle command:
 
     $ gradle --no-daemon --console plain classes jshell
 
@@ -63,8 +110,8 @@ System Requirements
  * Gradle
 
 
-Build & Publish
----------------
+Build and Publish
+-----------------
 
 Compile and build the .jar locally with:
 
@@ -74,6 +121,7 @@ Publish to your local Maven repo:
 
     $ ./gradlew publishToMavenLocal
 
+
 About
 -----
 
@@ -84,14 +132,17 @@ and this version solve some issues and adds the following features:
  - It works with **multi-module projects**
  - There is no need to set the env variable `JAVA_OPTS` with a bunch of
    of arguments _"--add-exports jdk.jshell/jdk.intern..."_
- - _Coming soon_: add special support to the **Spring Framework**
+ - It allows to run at the beginning of the session a _.jsh_ startup script
+ - _Coming soon_: special support to the **Spring Framework**
 
 Project: https://github.com/mrsarm/jshell-plugin
 
-Authors:
+### Authors
 
  - Mariano Ruiz <mrsarm@gmail.com>
  - https://github.com/bitterfox
    (original [project](https://github.com/bitterfox/jshell-gradle-plugin))
 
-License: (2020) [Apache Software License 2.0](https://www.apache.org/licenses/LICENSE-2.0).
+### License
+
+ - (2020) [Apache Software License 2.0](https://www.apache.org/licenses/LICENSE-2.0).

src/main/groovy/com/github/mrsarm/jshell/plugin/JShellPlugin.groovy

@@ -44,8 +44,30 @@ class JShellPlugin implements Plugin<Project> {
             }
             Thread.currentThread().setContextClassLoader(ClassLoader.getSystemClassLoader()) // promote class loader
             def path = pathSet.join(System.properties['os.name'].toLowerCase().contains('windows') ? ';' : ':')
-            jshellTask.logger.debug(":jshell executing with --class-path \"{}\"", path)
-            JavaShellToolBuilder.builder().run((String[])["--class-path", path].toArray())
+            jshellTask.logger.info(":jshell executing with --class-path \"{}\"", path)
+            String[] args = [
+                "--class-path", path,
+                "--startup", "DEFAULT",
+                "--startup", "PRINTING"
+            ]
+            if (project.findProperty("jshell.startup")) {
+                def jshellStartup = project.findProperty("jshell.startup")
+                jshellTask.logger.info(":jshell executing with --startup DEFAULT --startup PRINTING " +
+                                       "--startup \"{}\"", jshellStartup)
+                args = args + (String[]) ["--startup", jshellStartup]
+            } else {
+                def startupJsh = new File("${project.projectDir}/startup.jsh")
+                if (startupJsh.exists()) {
+                    def startupJshPath = startupJsh.absolutePath
+                    jshellTask.logger.info(":jshell executing with --startup DEFAULT --startup PRINTING" +
+                                           " --startup \"{}\"", startupJshPath)
+                    args = args + (String[]) ["--startup", startupJshPath]
+                } else {
+                    jshellTask.logger.info(":jshell did not find a startup.jsh script at the project dir " +
+                                           "nor a `jshell.startup` configuration")
+                }
+            }
+            JavaShellToolBuilder.builder().run(args)
         }
     }
 }