Cheat Sheet di Apache Ant

Installazione

Piattaforma	Comando
Ubuntu/Debian	`sudo apt update && sudo apt install ant`
RHEL/CentOS/Fedora	`sudo yum install ant` or `sudo dnf install ant`
Arch Linux	`sudo pacman -S apache-ant`
macOS (Homebrew)	`brew install ant`
Windows (Chocolatey)	`choco install ant`
Manual (All Platforms)	Download from apache.org, extract, set `ANT_HOME` and add `bin/` to `PATH`
Prerequisiti: È richiesto Java JDK 8+. Impostare `JAVA_HOME`variabile di ambiente.

Comandi di Base

Comando	Descrizione
`ant -version`	Visualizza la versione di Ant, la versione di Java e le informazioni del sistema operativo
`ant`	Esegui il target predefinito specificato in build.xml
`ant compile`	Esegui il target “compile” da build.xml
`ant clean`	Esegui il target “clean” (tipicamente rimuove gli artefatti di build)
`ant -projecthelp`	Elenca tutti i target disponibili con le relative descrizioni
`ant -p`	Forma breve di -projecthelp
`ant -f custom-build.xml`	Utilizzare un file di build alternativo invece di build.xml
`ant -buildfile mybuild.xml compile`	Specificare il file di build e il target da eseguire
`ant -verbose compile`	Mostra informazioni dettagliate di esecuzione
`ant -v test`	Forma breve di -verbose
`ant -debug package`	Verbosità massima per la risoluzione dei problemi
`ant -d deploy`	Forma breve di -debug
`ant -quiet test`	Output minimo, mostra solo gli errori
`ant -q build`	Forma breve di -quiet
`ant -logfile build.log compile`	Reindirizza l’output al file di log specificato
`ant -l output.log test`	Forma breve di -logfile

Utilizzo Avanzato

Comando	Descrizione
`ant -Denv=production deploy`	Imposta il valore della proprietà dalla riga di comando
`ant -Dversion=1.2.3 -Dbuild.number=456 package`	Imposta più proprietà
`ant -propertyfile custom.properties build`	Carica proprietà da file esterno
`ant -find`	Cerca nelle directory genitore il file build.xml
`ant -s`	Forma breve di -find
`ant -keep-going test`	Continuare l’esecuzione di target indipendenti dopo un errore
`ant -k test`	Forma abbreviata di -keep-going
`ant -diagnostics`	Visualizza informazioni di sistema e dettagli di configurazione
`ant -listener org.apache.tools.ant.listener.Log4jListener compile`	Aggiungi listener personalizzato per evento di build
`ant -logger org.apache.tools.ant.NoBannerLogger compile`	Utilizzare un’implementazione personalizzata di logger
`ant -inputhandler org.apache.tools.ant.input.SecureInputHandler deploy`	Utilizzare un gestore di input personalizzato per un input sicuro
`ant -noclasspath compile`	Ignora la variabile di ambiente CLASSPATH
`ant -autoproxy download`	Configura automaticamente le impostazioni del proxy Java
`ant -lib /path/to/jars compile`	Aggiungi directory di JARs al classpath di Ant
`ant -Dant.executor.class=org.apache.tools.ant.helper.ParallelExecutor build`	Abilitare l’esecuzione di attività parallele
`ant compile test package`	Esegui più target in sequenza
`ant -Dskip.tests=true package`	Salta condizionalmente le attività in base alla proprietà

Configurazione

Struttura Base di build.xml

<?xml version="1.0" encoding="UTF-8"?>
<project name="MyProject" default="build" basedir=".">
    
    <!-- Properties -->
    <property name="src.dir" value="src"/>
    <property name="build.dir" value="build"/>
    <property name="dist.dir" value="dist"/>
    <property name="lib.dir" value="lib"/>
    
    <!-- Classpath -->
    <path id="classpath">
        <fileset dir="${lib.dir}">
            <include name="**/*.jar"/>
        </fileset>
    </path>
    
    <!-- Clean target -->
    <target name="clean" description="Remove build artifacts">
        <delete dir="${build.dir}"/>
        <delete dir="${dist.dir}"/>
    </target>
    
    <!-- Init target -->
    <target name="init" depends="clean">
        <mkdir dir="${build.dir}"/>
        <mkdir dir="${dist.dir}"/>
    </target>
    
    <!-- Compile target -->
    <target name="compile" depends="init" description="Compile source code">
        <javac srcdir="${src.dir}" 
               destdir="${build.dir}"
               classpathref="classpath"
               includeantruntime="false"
               debug="true"
               source="11"
               target="11"/>
    </target>
    
    <!-- Build target -->
    <target name="build" depends="compile" description="Build JAR file">
        <jar destfile="${dist.dir}/${ant.project.name}.jar" 
             basedir="${build.dir}">
            <manifest>
                <attribute name="Main-Class" value="com.example.Main"/>
            </manifest>
        </jar>
    </target>
    
</project>

File build.properties

# Project configuration
project.name=MyApplication
project.version=1.0.0

# Directory structure
src.dir=src/main/java
test.dir=src/test/java
resources.dir=src/main/resources
build.dir=target/classes
dist.dir=dist

# Compiler settings
java.source.version=11
java.target.version=11
javac.debug=true
javac.deprecation=true

# Dependencies
lib.dir=lib

Caricamento delle Proprietà in build.xml

<property file="build.properties"/>
<property file="build-${env}.properties"/>
<property environment="env"/>

Filesets e Pattern Comuni

<!-- Include all Java files -->
<fileset dir="${src.dir}" includes="**/*.java"/>

<!-- Exclude test files -->
<fileset dir="${src.dir}">
    <include name="**/*.java"/>
    <exclude name="**/*Test.java"/>
</fileset>

<!-- Pattern sets for reuse -->
<patternset id="source.patterns">
    <include name="**/*.java"/>
    <include name="**/*.properties"/>
    <exclude name="**/*Test.java"/>
</patternset>

Casi d’Uso Comuni

Caso d’Uso: Compilazione di un’Applicazione Java Completa

# Clean previous builds
ant clean

# Compile, test, and package in one command
ant compile test package

# Build with specific environment properties
ant -Denv=production -propertyfile prod.properties package

# Create distribution with documentation
ant clean compile test package javadoc dist

Target di build.xml:

<target name="test" depends="compile">
    <junit printsummary="yes" haltonfailure="yes">
        <classpath>
            <path refid="classpath"/>
            <pathelement location="${build.dir}"/>
        </classpath>
        <batchtest fork="yes">
            <fileset dir="${test.dir}">
                <include name="**/*Test.java"/>
            </fileset>
        </batchtest>
    </junit>
</target>

<target name="javadoc">
    <javadoc sourcepath="${src.dir}" 
             destdir="${dist.dir}/docs"
             packagenames="com.example.*"/>
</target>

Caso d’Uso: Creazione di File WAR per Applicazione Web

# Build and package web application
ant clean compile war

# Deploy to application server
ant -Dserver.path=/opt/tomcat/webapps deploy

Configurazione di build.xml:

<target name="war" depends="compile">
    <war destfile="${dist.dir}/${project.name}.war" 
         webxml="web/WEB-INF/web.xml">
        <classes dir="${build.dir}"/>
        <lib dir="${lib.dir}"/>
        <fileset dir="web">
            <include name="**/*.jsp"/>
            <include name="**/*.html"/>
            <include name="**/*.css"/>
            <include name="**/*.js"/>
        </fileset>
    </war>
</target>

<target name="deploy" depends="war">
    <copy file="${dist.dir}/${project.name}.war" 
          todir="${server.path}"/>
</target>

Caso d’Uso: Compilazione di Progetto Multi-Modulo

# Build all modules in parallel
ant -Dant.executor.class=org.apache.tools.ant.helper.ParallelExecutor build-all

# Build specific module
ant -Dmodule=core build-module

# Build and run integration tests
ant build-all integration-test

build.xml con sottoprogetti:

<target name="build-all">
    <subant target="build">
        <fileset dir="." includes="*/build.xml"/>
    </subant>
</target>

<target name="build-module">
    <ant dir="${module}" target="build" inheritAll="false"/>
</target>

Caso d’Uso: Build Condizionali con Verifica delle Proprietà

# Skip tests during build
ant -Dskip.tests=true package

# Build only if sources changed
ant -Dincremental=true compile

# Production build with optimizations
ant -Doptimize=true -Ddebug=false production-build

build.xml con condizioni:

<target name="compile">
    <javac srcdir="${src.dir}" 
           destdir="${build.dir}"
           debug="${debug}"
           optimize="${optimize}">
        <classpath refid="classpath"/>
    </javac>
</target>

<target name="test" unless="skip.tests">
    <junit printsummary="yes">
        <classpath>
            <path refid="classpath"/>
            <pathelement location="${build.dir}"/>
        </classpath>
        <batchtest>
            <fileset dir="${test.dir}" includes="**/*Test.java"/>
        </batchtest>
    </junit>
</target>

<target name="package" depends="compile,test">
    <jar destfile="${dist.dir}/${ant.project.name}.jar" 
         basedir="${build.dir}"/>
</target>

Caso d’Uso: Migrazione e Distribuzione Database

# Run database migrations
ant -propertyfile db-config.properties db-migrate

# Deploy application with database updates
ant -Denv=staging db-migrate deploy

# Rollback database changes
ant -Dversion=1.2.0 db-rollback

build.xml con task SQL:

<target name="db-migrate">
    <sql driver="${db.driver}"
         url="${db.url}"
         userid="${db.user}"
         password="${db.password}"
         src="migrations/migrate-${version}.sql"
         print="yes"
         output="migration.log"/>
</target>

<target name="db-rollback">
    <sql driver="${db.driver}"
         url="${db.url}"
         userid="${db.user}"
         password="${db.password}"
         src="migrations/rollback-${version}.sql"/>
</target>

Migliori Pratiche

Utilizzare file di proprietà per la configurazione: Separare le impostazioni specifiche dell’ambiente dalla logica di build. Caricare le proprietà con <property file="build.properties"/> to keep build.xml clean and reusable.
Define meaningful target descriptions: Add descrizione attributes to public targets for better ant -aiutoprogetto output. This serves as built-in documentation for your build process.
Leverage target dependencies: Use dipende attribute to establish build order and avoid redundant task execution. Ant automatically handles dependency resolution.
Set includeantruntime="false" in javac tasks: Prevents Ant runtime libraries from polluting your application classpath, avoiding potential conflicts and reducing JAR size.
Use filesets and pattern sets for flexibility: Define reusable file patterns with <insiemedimodelli> and reference them in multiple targets. This makes maintenance easier and reduces duplication.
Implement incremental builds: Use <finoadata> conditions to skip compilation when source files haven’t changed, significantly speeding up development builds.
Version control your build files: Include build.xml, property files, and custom tasks in version control. Exclude generated directories like build/ and dist/ using .ignoragit.
Use macros for repeated task sequences: Define <definizionemacro> elements for common operations performed across multiple modules or targets, promoting DRY principles.
Separate concerns with imported build files: Split large build files into logical components (build-comune.xml, test-build.xml) e importarli per migliorare la manutenibilità.
Documentare la logica complessa con commenti: Utilizzare commenti XML per spiegare la logica di build non ovvia, l’utilizzo delle proprietà e le dipendenze, soprattutto in progetti condivisi o legacy.

Risoluzione dei problemi

Problema	Soluzione
`BUILD FAILED: build.xml does not exist`	Run `ant -find` to search parent directories, or specify file with `ant -f path/to/build.xml`
`Unable to locate tools.jar`	Set `JAVA_HOME` to JDK (not JRE) directory. Verify with `echo $JAVA_HOME` and ensure it points to JDK installation
`ClassNotFoundException` for custom tasks	Add JAR to Ant’s classpath using `-lib` option: `ant -lib /path/to/jars compile` or use `<taskdef>` with correct classpath
Compilation fails with encoding errors	Add `encoding="UTF-8"` attribute to `<javac>` task: `<javac srcdir="${src.dir}" encoding="UTF-8"/>`
Out of memory during build	Increase heap size: `export ANT_OPTS="-Xmx1024m -Xms512m"` (Linux/Mac) or `set ANT_OPTS=-Xmx1024m` (Windows)
Target not found error	Verify target name with `ant -projecthelp`. Check for typos and ensure target is defined in active build file
Circular dependency detected	Review `depends` attributes in targets. Ant cannot resolve circular references - redesign target dependencies
Permission denied when writing files	Verificare i permessi della directory e assicurarsi che Ant abbia accesso in scrittura. Eseguire con privilegi utente appropriati o modificare la proprietà della directory
`fork="true"` required but task fails	Some tasks (junit, java) require forking. Ensure `fork="true"` is set and `JAVA_HOME` points to valid JDK
Properties not being overridden	Properties are immutable in Ant - first definition wins. Set properties via command line (`-D`) before build file loads them
Slow builds with large filesets	Use `<uptodate>` conditions for incremental builds. Enable parallel execution with `-Dant.executor.class=org.apache.tools.ant.helper.ParallelExecutor`
JAR file manifest not correct	Use `<manifest>` element within `<jar>` task to specify Main-Class and other attributes explicitly

Riferimento Attività Ant Comuni

Attività	Descrizione	Esempio
`<javac>`	Compilare file sorgente Java	`<javac srcdir="src" destdir="build" includeantruntime="false"/>`
`<jar>`	Crea archivio JAR	`<jar destfile="dist/app.jar" basedir="build"/>`
`<war>`	Creare archivio WAR	`<war destfile="dist/app.war" webxml="web/WEB-INF/web.xml"/>`
`<copy>`	Copia file o directory	`<copy todir="backup"><fileset dir="src"/></copy>`
`<delete>`	Elimina file o directory	`<delete dir="build"/>`
`<mkdir>`	Crea directory	`<mkdir dir="dist"/>`
`<echo>`	Stampa messaggio	`<echo message="Building version ${version}"/>`
`<exec>`	Esegui comando di sistema	`<exec executable="git" args="rev-parse HEAD"/>`
`<junit>`	Esegui test JUnit	`<junit printsummary="yes" fork="yes"/>`
`<zip>`	Crea archivio ZIP	`<zip destfile="dist/src.zip" basedir="src"/>`
`<sql>`	Esegui istruzioni SQL	`<sql driver="${db.driver}" url="${db.url}" src="schema.sql"/>`