Most of the refactor. Need to switch machines.

crates/java/src/lib.rs

@@ -0,0 +1,49 @@
+pub mod compiler;
+pub mod error;
+pub mod runtime;
+
+use std::str::FromStr;
+
+pub use error::{Error, Result};
+use runtime::VMFlag;
+
+pub const JAVA_BIN_VM: &str = "java";
+pub const JAVA_BIN_COMPILER: &str = "javac";
+
+pub const JAVA_EXT_SOURCE: &str = "java";
+pub const JAVA_EXT_CLASS: &str = "class";
+
+pub const F_JAVA_VERSION: &str = ".java-version";
+
+/// Uses the java binary to parse its stdout for version information.
+///
+/// This is non-caching.
+pub fn get_javac_ver() -> Result<semver::Version> {
+    // TODO: Consider making this pull the version info from javac instead?
+
+    /*
+     * $ java --version
+     *      openjdk 21.0.9 2025-10-21
+     *      OpenJDK Runtime Environment (build 21.0.9+10)
+     *      OpenJDK 64-Bit Server VM (build 21.0.9+10, mixed mode, sharing)
+     */
+
+    Ok(semver::Version::from_str(
+        get_java_version_info()?
+            .lines()
+            .nth(0)
+            .ok_or(Error::EmptyStdout)?
+            .split_ascii_whitespace()
+            .nth(1)
+            .ok_or(Error::NthOutOfBounds)?,
+    )?)
+}
+
+/// Calls the java binary, returning the complete stdout version information.
+fn get_java_version_info() -> Result<String> {
+    Ok(
+        io::run_process(&[JAVA_BIN_VM, VMFlag::Version.to_string().as_str()])?
+            .0
+            .ok_or(Error::EmptyStdout)?,
+    )
+}