Chapter 1 Chapter 2

1. What is a build tool 
    A programmable tool that allows you to express automation requirements in executable and ordered tasks. 
    For example: you need to compile the source code, copy the class file to the specified directory, and then package it into usable software: 
        Step 1: Compile, Step 2: Copy the Class file to the specified directory, Step 3: Assemble and build. These steps are in order. 
        These tasks form a directed five-ring graph. 
2. Analysis of build tools 
    Build files: Contains configuration information, external dependencies, dependencies between tasks, etc. required for the build. 
    Build engine: Process the rules in the build file and execute them in the correct way. 
    Dependency Manager: Handles dependency definitions declared in build files. 
3. Java build tool 
    1: Ant 
    2: Maven 
    3: Gradle 
4. Next-generation build tool Gradle 
    Gradle is based on JVM and uses a Groovy-based language DSL. Learn from ant and maven. Provide support for multi-project builds 
5. Install Grade with 
    JDK1.5 or above, configure GRADLE_HOME, and verify that gradle is correctly installed with gradle -v. 
6. Start using the Gradle 
    Hello World example: 
        1: Create a build.gradle file. 
        2: Define an independent atomic operation --task 
        3: Use groovy syntax to write the following code:

            task helloWorld{
                doLast{
                    println 'Hello world'
                }
            }

        Note: tasks and actions are important elements of a DSL. The action doLast indicates the last execution of the task execution (<< also indicates doLast)

           task startSession <<{
                chant()
           }
           def chant(){
                ant.echo(message: 'repeat after me ...')      // Good integration with ant 
           }
            3 .times{
                task "yayGradle$it" <<{              // loop 3 times, exposing a parameter it 
                    println 'Gradle rocks'
                }
           }
           yayGradle0.dependsOn startSession             // The dependsOn keyword is used to describe dependencies between tasks. 
           yayGradle2.dependsOn yayGradle1 , yayGradle0
           task groupTherapy(dependsOn: yayGradle2)

7. List all tasks 
    gradle -q tasks 
    gradle -q tasks --all will list dependencies 
8. Multiple tasks execute 
    gradle -q yayGradle0 groupTherapy first execute yayGradle0 and then execute groupTherapy 
    //Usually the task is executed only once, in dependencies The same is true in the relationship. In the above sentence, yayGradle0 is only executed once. 
9. Run 
    gradle yG0 gT //gradle yayGradle0 groupTherapy     with 
camel case abbreviation