Gradle & Groovy

https://github.com/udacity/ud867

1. 

Gradle is a project automation tool that builds upon the concepts of Apache Ant and Apache Mavenand introduces a Groovy-based domain-specific language (DSL) instead of the more traditional XMLform of declaring the project configuration. Gradle uses a directed acyclic graph ("DAG") to determine the order in which tasks can be run.

Gradle was designed for multi-project builds which can grow to be quite large, and supports incremental builds by intelligently determining which parts of the build tree are up-to-date, so that any task dependent upon those parts will not need to be re-executed.

The initial plugins are primarily focused around Java, Groovy and Scala development and deployment, but more languages and project workflows are on the roadmap.

2. 

Groovy is an object-oriented programming language for the Java platform. It is a dynamic languagewith features similar to those of Python, Ruby, Perl, and Smalltalk. It can be used as a scripting language for the Java Platform, is dynamically compiled to Java Virtual Machine (JVM) bytecode, and interoperates with other Java code and libraries. Groovy uses a Java-like curly-bracket syntax. Most Java code is also syntactically valid Groovy, although semantics may be different.

3. how to run gradle

(1) create a file called "build.gradle", this is the default file that gradle will execute 

(2)run command

this command will execute the "build.gradle" file without execute any task in this file.

gradlew

this command will execute the task called "hello" in the "build.gradle" file

gradlew hello