From 4b46aaca92d2a33f051e30b3e1a4a5563bdb5565 Mon Sep 17 00:00:00 2001
From: Patrick Dowler <pdowler.cadc@gmail.com>
Date: Tue, 26 Mar 2024 12:55:52 -0700
Subject: [PATCH] add getLibraryVersion and refactor

---
 cadc-rest/build.gradle                        |  2 +-
 .../java/ca/nrc/cadc/rest/InitAction.java     | 73 +++++++++++++++++++
 .../java/ca/nrc/cadc/rest/RestAction.java     | 20 ++---
 3 files changed, 80 insertions(+), 15 deletions(-)

diff --git a/cadc-rest/build.gradle b/cadc-rest/build.gradle
index c948a6d2..d83e66e6 100644
--- a/cadc-rest/build.gradle
+++ b/cadc-rest/build.gradle
@@ -16,7 +16,7 @@ sourceCompatibility = 1.8
 
 group = 'org.opencadc'
 
-version = '1.3.19'
+version = '1.3.20'
 
 description = 'OpenCADC REST server library'
 def git_url = 'https://github.com/opencadc/core'
diff --git a/cadc-rest/src/main/java/ca/nrc/cadc/rest/InitAction.java b/cadc-rest/src/main/java/ca/nrc/cadc/rest/InitAction.java
index cc14fa6e..4a0b98d1 100644
--- a/cadc-rest/src/main/java/ca/nrc/cadc/rest/InitAction.java
+++ b/cadc-rest/src/main/java/ca/nrc/cadc/rest/InitAction.java
@@ -67,6 +67,8 @@
 
 package ca.nrc.cadc.rest;
 
+import ca.nrc.cadc.util.StringUtil;
+import java.io.IOException;
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.util.Map;
@@ -135,6 +137,77 @@ protected URL getResource(String resource) throws MalformedURLException {
         return servletContext.getResource(resource);
     }
     
+    /**
+     * Read the VERSION file and extract the semantic version number from a line
+     * with VER=1.2.3
+     * 
+     * @return version or null if VERSION file not found or does not have expected content
+     */
+    protected Version getVersionFromResource() {
+        try {
+            URL resURL = getResource("VERSION");
+            return getVersionFromResource(resURL);
+        }  catch (Exception ex) { 
+            log.warn("failed to extract version from VERSION file: " + ex);
+        }
+        return null;
+    }
+    
+    static Version getVersionFromResource(URL resURL) throws IOException {
+        if (resURL != null) {
+            String versionFileContent = StringUtil.readFromInputStream(resURL.openStream(), "UTF-8");
+            String[] lines = versionFileContent.split("\n");
+            for (String s : lines) {
+                if (s.startsWith("VER=")) {
+                    String ver = s.substring(4);
+                    return new Version(ver);
+                }
+            }
+        }
+        return null;
+    }
+    
+    /**
+     * Get the library version that provides the specified class.
+     * 
+     * @param probe class to search for
+     * @return library version in {name}-{major}.{minor} form 
+     */
+    protected static Version getLibraryVersion(Class probe) {
+        String ret = "no-version-found";
+        String rname = probe.getSimpleName() + ".class";
+        try {
+            
+            URL resURL = probe.getResource(rname);
+            log.debug("library URL: " + resURL);
+            // assume maven-central naming conventions for jar
+            // jar:file:/path/to/{library}-{ver}.jar!/package/subpackage/{rname}
+            if (resURL != null) {
+                String[] parts = resURL.toExternalForm().split("[:!]");
+                int i = 0;
+                for (String p : parts) {
+                    if (p.endsWith(".jar")) {
+                        int s = p.lastIndexOf('/');
+                        String ver = p.substring(s + 1); // {library}-{ver}.jar
+                        ver = ver.replace(".jar", "");   // {library}-{ver}
+                        
+                        // extract {major}.{minor} only
+                        String[] mmp = ver.split("\\.");
+                        if (mmp.length > 2) {
+                            ret = mmp[0] + "." + mmp[1];
+                        } else {
+                            ret = ver;
+                        }
+                    }
+                }
+            }
+        } catch (Exception ex) {
+            log.error("failed to find version for " + rname + " from classpath", ex);
+        }
+        
+        return new Version(ret);
+    }
+    
     /**
      * Initialisation implemented by subclass. This method gets called once during startup/deployment.
      */
diff --git a/cadc-rest/src/main/java/ca/nrc/cadc/rest/RestAction.java b/cadc-rest/src/main/java/ca/nrc/cadc/rest/RestAction.java
index f191a383..abccc778 100644
--- a/cadc-rest/src/main/java/ca/nrc/cadc/rest/RestAction.java
+++ b/cadc-rest/src/main/java/ca/nrc/cadc/rest/RestAction.java
@@ -83,7 +83,6 @@
 import ca.nrc.cadc.net.TransientException;
 import ca.nrc.cadc.reg.client.RegistryClient;
 import ca.nrc.cadc.util.StringUtil;
-
 import java.io.IOException;
 import java.io.OutputStream;
 import java.net.MalformedURLException;
@@ -92,9 +91,7 @@
 import java.security.PrivilegedExceptionAction;
 import java.security.cert.CertificateException;
 import java.util.Map;
-
 import javax.servlet.ServletContext;
-
 import org.apache.log4j.Logger;
 
 /**
@@ -270,22 +267,17 @@ protected String getServerImpl() {
     protected Version getVersionFromResource() {
         try {
             URL resURL = getResource("VERSION");
-            if (resURL != null) {
-                String versionFileContent = StringUtil.readFromInputStream(resURL.openStream(), "UTF-8");
-                String[] lines = versionFileContent.split("\n");
-                for (String s : lines) {
-                    if (s.startsWith("VER=")) {
-                        String ver = s.substring(4);
-                        return new Version(ver);
-                    }
-                }
-            }
-        } catch (Exception ex) { 
+            return InitAction.getVersionFromResource(resURL);
+        }  catch (Exception ex) { 
             log.warn("failed to extract version from VERSION file: " + ex);
         }
         return null;
     }
     
+    protected static Version getLibraryVersion(Class probe) {
+        return InitAction.getLibraryVersion(probe);
+    }
+    
     /**
      * Create inline content handler to process non-form data. Non-form data could
      * be a document or part of a multi-part request). Null return value is allowed