WebLogic 라이브러리 안정성 검증 로직 강화:

- jboss-logging/Guava 클래스 로드시충돌 점검 추가
- ReadinessController에 관련 체크 로직 반영

src/main/java/com/eactive/apim/portal/apps/ReadinessController.java

@@ -5,6 +5,7 @@ import java.sql.SQLException;
 
 import javax.sql.DataSource;
 
+import org.jboss.logging.Logger;
 import org.springframework.beans.factory.annotation.Qualifier;
 import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
@@ -12,19 +13,28 @@ import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.RestController;
 import org.thymeleaf.spring5.SpringTemplateEngine;
 
+import com.google.common.util.concurrent.Futures;
+
 /**
  * Readiness probe.
  *
  * <p>Distinct from {@link HealthCheckController} (liveness — servlet alive?).
  * This endpoint validates both EMS and Gateway datasources via JDBC
- * {@code Connection.isValid(timeout)}, and the Thymeleaf {@link SpringTemplateEngine}
+ * {@code Connection.isValid(timeout)}, plus three libraries that WebLogic's
- * configuration, to confirm the app is ready to serve real page requests.
+ * oracle_common bundles at a different version from this app (see weblogic.xml
+ * {@code prefer-application-packages}): Thymeleaf's {@link SpringTemplateEngine}
+ * (jackson), jboss-logging, and Guava.
  *
- * <p>The template-engine check exists because this controller bypasses view
+ * <p>These exist because this controller bypasses view resolution entirely
- * resolution entirely (plain {@code @RestController} JSON) — a broken
+ * (plain {@code @RestController} JSON) — a classpath split between the app's
- * {@code TemplateEngine.getConfiguration()} (e.g. classpath split causing
+ * copy and WebLogic's bundled copy of a preferred package can throw
- * {@link java.util.ServiceConfigurationError} during dialect/module discovery)
+ * {@link LinkageError}/{@link java.util.ServiceConfigurationError} only on the
- * previously left every real page returning 500 while this probe still reported 200.
+ * real code paths that touch it, while this probe kept reporting 200. That
+ * already happened once for jackson (Thymeleaf's dialect/module discovery
+ * failed on every real page while /health/ready stayed green) — jboss-logging
+ * and Guava carry the same risk (confirmed version mismatch against
+ * oracle_common, not yet observed failing in production) so they get the same
+ * kind of forced-touch check here.
  *
  * <p>HTTP 200 + JSON when all checks pass.
  * <p>HTTP 503 + JSON when any check fails — body still includes the per-component
@@ -50,16 +60,21 @@ public class ReadinessController {
 
     @GetMapping(value = "/health/ready", produces = MediaType.APPLICATION_JSON_VALUE)
     public ResponseEntity<String> ready() {
-        String ems  = check(portalDataSource);
+        String ems     = check(portalDataSource);
-        String gw   = check(gatewayDataSource);
+        String gw      = check(gatewayDataSource);
-        String view = checkTemplateEngine();
+        String view    = checkTemplateEngine();
-        boolean ok = "UP".equals(ems) && "UP".equals(gw) && "UP".equals(view);
+        String logging = checkJbossLogging();
+        String guava   = checkGuava();
+        boolean ok = "UP".equals(ems) && "UP".equals(gw) && "UP".equals(view)
+                && "UP".equals(logging) && "UP".equals(guava);
 
         String body = "{"
                 + "\"status\":\""  + (ok ? "UP" : "DOWN") + "\","
-                + "\"ems\":\""     + ems  + "\","
+                + "\"ems\":\""     + ems     + "\","
-                + "\"gateway\":\"" + gw   + "\","
+                + "\"gateway\":\"" + gw      + "\","
-                + "\"view\":\""    + view + "\""
+                + "\"view\":\""    + view    + "\","
+                + "\"logging\":\"" + logging + "\","
+                + "\"guava\":\""   + guava   + "\""
                 + "}";
 
         return ResponseEntity.status(ok ? 200 : 503)
@@ -76,11 +91,40 @@ public class ReadinessController {
             templateEngine.getConfiguration();
             return "UP";
         } catch (Throwable t) {
-            String msg = t.getMessage() == null ? t.getClass().getSimpleName() : t.getMessage();
+            return down(t);
-            return "DOWN:" + msg.replace('"', '\'').replace('\n', ' ').replace('\r', ' ');
         }
     }
 
+    /** Forces jboss-logging's {@code Logger} + its bound provider (LogManager/JBoss/JUL
+     *  discovery) to load and actually run a log-level check, not just resolve the class. */
+    private static String checkJbossLogging() {
+        try {
+            Logger log = Logger.getLogger(ReadinessController.class);
+            log.isDebugEnabled();
+            return "UP";
+        } catch (Throwable t) {
+            return down(t);
+        }
+    }
+
+    /** {@code Futures.immediateFuture} touches Guava's {@code util.concurrent} machinery
+     *  (AbstractFuture/InternalFutureFailureAccess) — the part backed by the separate
+     *  {@code failureaccess} jar, which is exactly where an app/WebLogic version mismatch
+     *  would split across classloaders. */
+    private static String checkGuava() {
+        try {
+            Futures.immediateFuture(Boolean.TRUE).isDone();
+            return "UP";
+        } catch (Throwable t) {
+            return down(t);
+        }
+    }
+
+    private static String down(Throwable t) {
+        String msg = t.getMessage() == null ? t.getClass().getSimpleName() : t.getMessage();
+        return "DOWN:" + msg.replace('"', '\'').replace('\n', ' ').replace('\r', ' ');
+    }
+
     private static String check(DataSource ds) {
         if (ds == null) return "DOWN:NO_DATASOURCE";
         try (Connection c = ds.getConnection()) {