Merge branch 'java-home' into 'main'

graphmarkup: Support JAVA_HOME for plantuml launch

Closes #199

See merge request subplot/subplot!175

1 files changed, 26 insertions, 4 deletions

diff --git a/src/graphmarkup.rs b/src/graphmarkup.rs
index 4f6d737..1e6b7c1 100644
--- a/src/graphmarkup.rs
+++ b/src/graphmarkup.rs
@@ -2,7 +2,10 @@ use crate::{Result, SubplotError};
 
 // use roadmap;
 
+use std::env;
+use std::ffi::OsString;
 use std::io::prelude::*;
+use std::path::PathBuf;
 // use std::path::Path;
 use std::process::{Command, Stdio};
 
@@ -116,12 +119,28 @@ impl PlantumlMarkup {
             markup: markup.to_owned(),
         }
     }
+
+    // If JAVA_HOME is set, and PATH is set, then:
+    // Check if JAVA_HOME/bin is in PATH, if not, prepend it and return a new
+    // PATH
+    fn build_java_path() -> Option<OsString> {
+        let java_home = env::var_os("JAVA_HOME")?;
+        let cur_path = env::var_os("PATH")?;
+        let cur_path: Vec<_> = env::split_paths(&cur_path).collect();
+        let java_home = PathBuf::from(java_home);
+        let java_bin = java_home.join("bin");
+        if cur_path.iter().any(|v| v.as_os_str() == java_bin) {
+            // No need to add JAVA_HOME/bin it's already on-path
+            return None;
+        }
+        env::join_paths(Some(java_bin).iter().chain(cur_path.iter())).ok()
+    }
 }
 
 impl GraphMarkup for PlantumlMarkup {
     fn as_svg(&self) -> Result<Vec<u8>> {
-        let mut child = Command::new("java")
-            .arg("-Djava.awt.headless=true")
+        let mut cmd = Command::new("java");
+        cmd.arg("-Djava.awt.headless=true")
             .arg("-jar")
             .arg("/usr/share/plantuml/plantuml.jar")
             .arg("--")
@@ -130,8 +149,11 @@ impl GraphMarkup for PlantumlMarkup {
             .arg("-v")
             .stdin(Stdio::piped())
             .stdout(Stdio::piped())
-            .stderr(Stdio::piped())
-            .spawn()?;
+            .stderr(Stdio::piped());
+        if let Some(path) = Self::build_java_path() {
+            cmd.env("PATH", path);
+        }
+        let mut child = cmd.spawn()?;
         if let Some(stdin) = child.stdin.as_mut() {
             stdin.write_all(self.markup.as_bytes())?;
             let output = child.wait_with_output()?;