While Jenkins technically runs on Java 1.5+, modern deployments should consider several technical factors:

// Example system property check in Groovy (Jenkins script console)
println "Current JVM: ${System.getProperty('java.version')}"
println "JVM Vendor: ${System.getProperty('java.vendor')}"
println "64-bit: ${System.getProperty('sun.arch.data.model')}"

For stable Jenkins operations:

• Minimum: Java 8u191+ (LTS version)
• Recommended: Java 11 (current LTS)
• Cutting-edge: Java 17 (next LTS) with plugin compatibility checks

Windows Server 2003 (32-bit):

# Batch script to launch Jenkins with specific Java version
set JENKINS_JAVA_CMD="C:\Program Files\Java\jre1.8.0_291\bin\java"
set JENKINS_JAVA_OPTIONS=-Xmx512m -Dfile.encoding=UTF-8
%JENKINS_JAVA_CMD% %JENKINS_JAVA_OPTIONS% -jar jenkins.war

64-bit Systems:

# Linux systemd unit file example
[Service]
Environment="JAVA_HOME=/usr/lib/jvm/java-11-openjdk-amd64"
ExecStart=/usr/bin/java -Xmx2g -XX:+UseG1GC -jar /opt/jenkins/jenkins.war

Common issues and solutions:

1. Plugin compatibility: Some older plugins may require Java 8
2. Memory management: 64-bit JVM recommended for large instances (>2GB heap)
3. Security: Always use the latest patch version of your chosen Java release

Comparative test results (Jenkins 2.346.1):

When setting up Jenkins on Windows, the Java version selection impacts both stability and performance. While the official documentation states Jenkins requires JRE 1.5 or later, practical considerations demand more nuanced decisions.

For modern Jenkins installations (2.346+), we recommend:

• Java 8 (LTS) for maximum plugin compatibility
• Java 11 (LTS) for security updates and performance
• Java 17 (LTS) for newest features (verify plugin support)

For 32-bit Windows Server 2003:

set JENKINS_JAVA_CMD="C:\Program Files (x86)\Java\jre1.8.0_301\bin\java.exe"
java -jar jenkins.war --httpPort=8080

For 64-bit systems:

set JENKINS_JAVA_HOME="C:\Program Files\Java\jdk-11.0.12"
java -XX:+UseG1GC -Xmx2048m -jar jenkins.war

Add these parameters to jenkins.xml for production environments:

<arguments>
  -Xrs -Xmx4g -XX:MaxMetaspaceSize=512m
  -Dhudson.model.DirectoryBrowserSupport.CSP=""
  -Djenkins.install.runSetupWizard=false
</arguments>

Check your current runtime with this Groovy script in Jenkins Script Console:

println "Java Version: ${System.getProperty('java.version')}"
println "JVM Vendor: ${System.getProperty('java.vendor')}"
println "JVM Architecture: ${System.getProperty('sun.arch.data.model')}bit"

Some legacy plugins (like Subversion 1.10) require Java 8. Test thoroughly before upgrading Java versions in existing installations.