73. Spring Boot AntLib Module

The Spring Boot AntLib module provides basic Spring Boot support for Apache Ant. You can use the module to create executable jars. To use the module, you need to declare an additional spring-boot namespace in your build.xml, as shown in the following example:

<project xmlns:ivy="antlib:org.apache.ivy.ant"
	xmlns:spring-boot="antlib:org.springframework.boot.ant"
	name="myapp" default="build">
	...
</project>

You need to remember to start Ant using the -lib option, as shown in the following example:

$ ant -lib <folder containing spring-boot-antlib-2.1.11.BUILD-SNAPSHOT.jar>
[Tip]Tip

The “Using Spring Boot” section includes a more complete example of using Apache Ant with spring-boot-antlib.

73.1 Spring Boot Ant Tasks

Once the spring-boot-antlib namespace has been declared, the following additional tasks are available:

73.1.1 spring-boot:exejar

You can use the exejar task to create a Spring Boot executable jar. The following attributes are supported by the task:

AttributeDescriptionRequired

destfile

The destination jar file to create

Yes

classes

The root directory of Java class files

Yes

start-class

The main application class to run

No (the default is the first class found that declares a main method)

The following nested elements can be used with the task:

ElementDescription

resources

One or more Resource Collections describing a set of Resources that should be added to the content of the created jar file.

lib

One or more Resource Collections that should be added to the set of jar libraries that make up the runtime dependency classpath of the application.

73.1.2 Examples

This section shows two examples of Ant tasks.

Specify start-class. 

<spring-boot:exejar destfile="target/my-application.jar"
		classes="target/classes" start-class="com.example.MyApplication">
	<resources>
		<fileset dir="src/main/resources" />
	</resources>
	<lib>
		<fileset dir="lib" />
	</lib>
</spring-boot:exejar>

Detect start-class. 

<exejar destfile="target/my-application.jar" classes="target/classes">
	<lib>
		<fileset dir="lib" />
	</lib>
</exejar>

73.2 spring-boot:findmainclass

The findmainclass task is used internally by exejar to locate a class declaring a main. If necessary, you can also use this task directly in your build. The following attributes are supported:

AttributeDescriptionRequired

classesroot

The root directory of Java class files

Yes (unless mainclass is specified)

mainclass

Can be used to short-circuit the main class search

No

property

The Ant property that should be set with the result

No (result will be logged if unspecified)

73.2.1 Examples

This section contains three examples of using findmainclass.

Find and log. 

<findmainclass classesroot="target/classes" />

Find and set. 

<findmainclass classesroot="target/classes" property="main-class" />

Override and set. 

<findmainclass mainclass="com.example.MainClass" property="main-class" />