Java Requirements Resolution

Java runtime detection and version validation for AutoRest Java-based extensions. Provides simple Java availability checking with version parsing from the standard java -version command output.

Capabilities

Java Requirement Resolution

Resolves Java runtime requirements by executing java -version and parsing the version output.

/**
 * Resolve Java runtime requirement
 * @param requirement - Java requirement configuration
 * @returns Resolution with Java command and version, or error details
 */
function resolveJavaRequirement(
  requirement: SystemRequirement
): Promise<SystemRequirementResolution | SystemRequirementError>;

Usage Example:

import { resolveJavaRequirement } from "@autorest/system-requirements";

// Basic Java requirement
const result = await resolveJavaRequirement({ version: ">=11" });
if ("error" in result) {
  console.error("Java not found or version incompatible:", result.message);
} else {
  console.log(`Java resolved: ${result.command}`);
  console.log(`Java name: ${result.name}`); // "java"
}

// Using custom Java path via environment variable
const customResult = await resolveJavaRequirement({
  version: ">=17",
  environmentVariable: "JAVA_HOME_PATH"
});

Java Detection Logic

The Java resolver follows this detection process:

1. Environment Variable: If environmentVariable is specified in the requirement, uses that path
2. System Java: Falls back to java command in system PATH
3. Version Parsing: Executes java -version and parses output using regex pattern
4. Version Validation: Compares parsed version against requirement using semantic versioning

Version Detection

Java version detection parses the output of java -version command, which typically looks like:

java version "11.0.12"
OpenJDK Runtime Environment...

The version string is extracted using the regex pattern: /java version "(.*)"/

Constants

/** Java executable name used in system requirement resolution */
const JavaExeName = "java";

Error Handling

Common Java resolution errors include:

• Command not found: java executable is not in PATH and no environment variable specified
• Version incompatible: Java version doesn't satisfy the requirement
• Version parsing failed: Unable to parse version from java -version output
• Execution failed: java -version command failed to execute

The resolver provides detailed error messages to help diagnose Java installation and configuration issues.